Gkgn0675 Iss 4.pdf

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Issue Four September 2015 Rail Industry Guidance Note for GK/RT0075 Lineside Signal Spacing and Speed Signage

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Guidance on Lineside Signal Spacing and Speed Signage

Published by

GN

GK/GN0675

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage Issue record Issue

Date

Comments

One

March 2011

Original document produced to support GK/RT0075 issue one, Lineside Signal Spacing and Speed Signage.

Two

September 2011

Three

September 2014

Small scale change to correct inconsistencies between GK/RT0075, issue one, Lineside Signal Spacing and Speed Signage, and its associated guidance note GK/GN0675. The only changes to this guidance note are the inclusion of missing word ‘section’ in 3.3.5.5 a), and deletion of section D.2.4.1 d) which was a duplication of D.2.4.1 c). Guidance revised to support the reissue of GK/RT0075 from issue two to three arising from project 12/033 to remove the requirement for a risk assessment before an emergency speed restriction is applied (E.2.1). Additional revisions include:

Four

September 2015

 Changes made to address typographical errors in GN Table 1, GN Table 2, Table B.1 and Table X-3.  Revisions to clauses 2.1.3b), 3.3.2.4, 3.4.1.4a), D.1.1.2, D.2.5.1a), D.2.5.2, D.4.2.1 and E.2 (with the addition of guidance GN268).  Removal of GN18b) - GN18c) becomes b).  New clause at D.2.5.3.  Updates to Figure D-21 (with the addition of guidance GN242) and Figure D-27.  The removal of clause D.4.2.3.  New guidance at GN65, GN191a and GN191b.  Last sentence of GN263 deleted.  Updates to document definitions. Guidance revised to support the reissue of GK/RT0075 from issue three to issue four to modify the requirements in 3.4.1.4 for the provision and position of warning boards for temporary speed restrictions (TSRs) with additional changes which include:  Minor clarification in clause 1.1.  Re-instatement of reference in clause 2.1.3 to excess signal braking distances.  Easement in clause D.2.1.2 for the non-standard positioning of warning boards (and associated AWS) for TSRs and associated GN202a.  Amendment of Tables X-1, X-2 and X-3 and the corresponding changes to the imperial (yards) braking distances tables at X-11, X-12 and X-13.

Amended or additional parts and / or sections of revised pages have been marked by a vertical black line in the adjacent margin.

Page 2 of 103 GK/GN0675 Issue Four September 2015

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Guidance on Lineside Signal Spacing and Speed Signage Superseded documents The following Rail Industry Guidance Note is superseded, either in whole or in part as indicated: Superseded Documents

Sections Superseded

Date when sections are superseded

GK/GN0675 issue three Guidance on Lineside Signal Spacing and Speed Signage

All

05 December 2015

GK/GN0675 issue three Guidance on Lineside Signal Spacing and Speed Signage, is withdrawn as of 05 December 2015.

Supply The authoritative version of this document is available at www.rgsonline.co.uk. Enquiries on this document can be forwarded to [email protected].

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Guidance on Lineside Signal Spacing and Speed Signage Contents Section Part 1 1.1 1.2 1.3 Part 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Part 3 3.1

Description Introduction Purpose of this document Copyright Approval and authorisation of this document Guidance on Requirements for Lineside Signal Spacing Compatibility requirements for lineside signal spacing Requirement for signal spacing Determining minimum signalling braking distances Acceptable variations in signal spacing Consistency of signalling braking distances Four-aspect signalling Use of attainable speed to determine minimum signal spacing Requirements at infrastructure manager boundaries Guidance on Requirements for Signing of Permissible Speeds and Speed Restrictions Compatibility requirements for signing of permissible speeds and speed restrictions Requirements for permissible speeds and temporary speed restrictions Signs for permissible speeds Provision of signs for temporary and emergency speed restrictions Application of this Document Application – infrastructure managers Application – railway undertakings Health and safety responsibilities

Page 7 7 7 7 8 8 9 10 14 17 18 21 22 24

Signalling Braking Distance Data for all Trains Composite table for all trains (metres)

24 25 29 45 50 50 50 50 51 51 51

Appendix B B.1

Signalling Braking Distances for Passenger Trains Composite table for passenger trains (metres)

55 55

Appendix C C.1

Signalling Braking Distances for Trains with Enhanced Braking (9%g mean) Table for trains with enhanced braking (9%g mean) in metres

59 59

Appendix D D.1 D.2 D.3 D.4

Temporary Speed Restrictions Position of speed indicators and termination indicators Temporary speed restriction warning boards and AWS equipment Requirements for adjacent temporary speed restrictions Altering temporary speed restrictions

63 63 65 79 83

Appendix E E.1 E.2

Emergency Speed Restrictions Management of emergency speed restrictions Provision of speed indicators, warning boards and AWS equipment

86 86 86

Appendix X Table X-1 Table X-2 Table X-3 Table X-4 Table X-5 Table X-6 Table X-7 Table X-8 Table X-9 Table X-10 GN Table X-11

Deceleration Distances Deceleration distance in metres to speed restriction of 10 mph Deceleration distance in metres to speed restriction of 20 mph Deceleration distance in metres to speed restriction of 30 mph Deceleration distance in metres to speed restriction of 40 mph Deceleration distance in metres to speed restriction of 50 mph Deceleration distance in metres to speed restriction of 60 mph Deceleration distance in metres to speed restriction of 70 mph Deceleration distance in metres to speed restriction of 80 mph Deceleration distance in metres to speed restriction of 90 mph Deceleration distance in metres to speed restriction of 100 mph Deceleration distance in yards to speed restriction of 10 mph

88 88 89 90 90 91 91 92 92 92 93 93

3.2 3.3 3.4 Part 4 4.1 4.2 4.3 Appendices Appendix A A.1

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Guidance on Lineside Signal Spacing and Speed Signage GN Table X-12 GN Table X-13 GN Table X-14 GN Table X-15 GN Table X-16 GN Table X-17 GN Table X-18 GN Table X-19 GN Table X-20

Deceleration distance in yards to speed restriction of 20 mph Deceleration distance in yards to speed restriction of 30 mph Deceleration distance in yards to speed restriction of 40 mph Deceleration distance in yards to speed restriction of 50 mph Deceleration distance in yards to speed restriction of 60 mph Deceleration distance in yards to speed restriction of 70 mph Deceleration distance in yards to speed restriction of 80 mph Deceleration distance in yards to speed restriction of 90 mph Deceleration distance in yards to speed restriction of 100 mph

94 95 95 96 96 97 97 97 98

Appendix Y

Key to Symbols Used in this Standard

99

Definitions

100

Abbreviations and Acronyms

102

References

103

Tables Table 1 Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure D-1 Figure D-2 Figure D-3 RSSB

Exemptions from the compatibility check

9

Example of a permissible speed indicator Example of two or more successive reductions in speed Example of a standard differential permissible speed indicator Example of a standard differential permissible speed warning indicator Examples of a non-standard differential permissible speed indicator Examples of a non-standard differential permissible speed warning indicator Example of permissible speed indicator at converging junction Example of permissible speed indicator at diverging junction with speed reduction on diverging route only Example of permissible speed indicator at diverging junction with speed reduction (equal speed) on both routes Example of permissible speed indicator at diverging junction with speed reduction on both routes (different speeds) Example of permissible speed indicator at diverging junction with no straight route Example of permissible speed warning indicator (simple case) Example of permissible speed warning indicator for successive reductions in speed Example of successive reductions in speed where a further permissible speed warning indicator is required Example of positioning of permissible speed warning indicator where deceleration distance falls within lower speed section Example of positioning of permissible speed warning indicator where deceleration distance encompasses lower speed section Example of permissible speed warning indicators at converging junction Example of permissible speed warning indicator for diverging junction positioned at a signal that displays a cautionary aspect Example of permissible speed warning indicator for speed reduction on a diverging route Example of movement via crossing not requiring temporary speed restriction signs Example of a commencement and termination indicator Example of an emergency indicator Example of differential speed indicators Example of speed indicators at converging junction (D.1.2.1) Example of TSR over trailing end of crossover (D.1.3.2) Example of TSR over facing end of crossover (D.1.3.3)

29 30 32 32 33 33 34 35 35 36 36 36 37 38 39 39 41 42 43 45 46 47 48 64 65 65

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Guidance on Lineside Signal Spacing and Speed Signage Figure D-4 Figure D-5 Figure D-6 Figure D-7 Figure D-8 Figure D-9 Figure D-10 Figure D-11 Figure D-12 Figure D-13 Figure D-14 Figure D-15 Figure D-16 Figure D-17 Figure D-18 Figure D-19 Figure D-20 Figure D-21 Figure D-22 Figure D-23 Figure D-24 Figure D-25 Figure D-26 Figure D-27 Figure D-28 Figure E-1

Example of TSR with a higher permissible speed on approach (D.2.1.4) Example of TSR with a lower permissible speed on approach (D.2.1.5) Example of TSR with warning board at commencement of higher permissible speed (D.2.1.6) Example of warning board positioning at a converging junction (D.2.2.1) Example of warning board positioning at a diverging junction (D.2.3.1) Example of a diverging junction with warning board located at the facing points (D.2.3.2) Example of a diverging junction where signal is approach released from red (D.2.3.3) Example of a diverging junction where signal is approach released from a higher aspect (D.2.3.4) Example of a diverging junction where no previous routing advice is given (D.2.3.5) Example of usual positioning of AWS magnets. (D.2.4.1a) Example of critical positioning of AWS magnets (D.2.4.1c) Example of warning board at signal with signal AWS electromagnet disconnected (D.2.4.4) Example of disconnection of suppressor on existing magnet (D.2.4.5) Example showing use of AWS cancelling indicator (D.2.4.6 / D.2.4.7) Another example showing use of AWS cancelling indicator (D.2.4.6 / D.2.4.7) Example showing provision of a warning board on an unfitted line leading to a fitted line (D.2.4.8) Example showing disconnection of AWS in advance of protecting signal leading to a fitted line (D.2.4.9) Example showing use of repeater warning boards (D.2.5.2) Example of a lower TSR followed by a higher TSR (D.3.1.1) Example of a higher TSR followed by a lower TSR (D.3.2.1) Another example of a higher TSR followed by a lower TSR (D.3.2.1) Example of co-incident warning boards for diverging routes (D.3.3.2) Example of successive speed restrictions on the same line (D.3.3.3) Example showing a moving TSR where the warning board cannot be moved (D.4.1.2) Example of a TSR not imposed or withdrawn early (D.4.2.2) Example of arrangements for emergency speed restriction (E.2.2)

66 67 67 68 68 69 70 71 72 73 73 74 75 76 76 77 78 79 80 80 80 81 82 83 84 87

Figures (Guidance) GN Figure 1 Spacing of 4-aspect signals – preferred arrangement (see 2.6.1) GN Figure 2 Spacing of 4-aspect signals – alternative arrangement (see 2.6.2) GN Figure 3 Spacing of 4-aspect signals with consecutive double yellows GN Figure 4 Spacing of 4-aspect signals at station with mid-platform signal GN Figure 5 Use of attainable speed at signal beyond converging junction GN Figure 6 Showing the use of excess speed approaching a signal GN Figure 7 Composite curves for all trains (metres) GN Figure 8 Composite curves for all trains (yards) GN Figure 9 Composite curves for passenger trains (metres) GN Figure 10 Composite curves for passenger trains (yards) GN Figure 11 Curves for trains with enhanced braking (9%g mean) in metres GN Figure 12 Curves for trains with enhanced braking (9%g mean) in yards

18 19 19 20 21 22 52 54 56 58 60 62

Tables (Guidance) GN Table 1 Composite table for all trains (yards) GN Table 2 Composite table for passenger trains (yards) GN Table 3 Table for trains with enhanced braking (9%g mean) in yards

53 57 61

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Guidance on Lineside Signal Spacing and Speed Signage Part 1 1.1

Introduction Purpose of this document This document gives guidance on interpreting the requirements of Railway Group Standard GK/RT0075 issue three Lineside Signal Spacing and Speed Signage. It does not constitute a recommended method of meeting any set of mandatory requirements. Relevant requirements in GK/RT0075 are reproduced in the sections that follow. Guidance is provided as a series of sequentially numbered sections prefixed ‘GN’ immediately below the text to which it relates. Where there is no guidance given, this is stated. The scope of this document does not include compatibility of lineside signalling and speed signage with train driving processes when an in-cab signalling system is in use. Specific responsibilities and compliance requirements are laid down in the Railway Group Standard itself.

1.2

Copyright Copyright in the Railway Group documents is owned by Rail Safety and Standards Board Limited. All rights are hereby reserved. No Railway Group document (in whole or in part) may be reproduced, stored in a retrieval system, or transmitted, in any form or means, without the prior written permission of Rail Safety and Standards Board Limited, or as expressly permitted by law. Rail Safety and Standards Board (RSSB) members are granted copyright licence in accordance with the Constitution Agreement relating to Rail Safety and Standards Board Limited. In circumstances where Rail Safety and Standards Board Limited has granted a particular person or organisation permission to copy extracts from Railway Group documents, Rail Safety and Standards Board Limited accepts no responsibility for, nor any liability in connection with, the use of such extracts, or any claims arising therefrom. This disclaimer applies to all forms of media in which extracts from Railway Group Standards may be reproduced.

1.3

Approval and authorisation of this document The content of this document was approved by the Control Command and Signalling (CCS) Standards Committee on 09 July 2015. This document was authorised by RSSB on 31 July 2015.

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Guidance on Lineside Signal Spacing and Speed Signage Part 2 2.1

Guidance on Requirements for Lineside Signal Spacing Compatibility requirements for lineside signal spacing 2.1.1

GE/RT8270 sets out the process for the assessment of compatibility that is required whenever a material change is to be made that affects the interface between the signalling system and railway undertakings or any infrastructure managers that operate stations.

2.1.2

The assessment of compatibility shall check that the signalling spacing data used to determine minimum signalling braking distances (further requirements are set out in 2.3) is compatible with all of the following:

2.1.3

a)

The types of rolling stock that will be operated on the route.

b)

The maximum speeds that the rolling stock will be authorised to operate on the route.

c)

The maximum attainable speeds of the rolling stock, where this is used to determine minimum signalling braking distances.

The assessment of compatibility shall check that the actual signalling braking distance is compatible with the SPAD risk mitigation measures that will be put in place by the railway undertakings, where any of the following apply: a)

There is more than 50% excess signalling braking distance, except where an exemption applies (see Table 1).

b)

A variation in excess signalling braking distances means that the distance between the signals displaying the first cautionary aspect and the stop aspect is reduced by 34% or more, compared with the excess signalling braking distance for the preceding sequence of signals on the same line. In four-aspect signalling areas, where the distance between the signals displaying the single yellow aspect and the red aspect is less than one third of the distance between the signals displaying the double yellow aspect and the red aspect.

c)

Situation

a

b

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50%

Where signals control movements in the same direction on parallel lines that have different permissible speeds, and signals are positioned adjacent to each other to minimise the risk of driver misread or disregard

The compatibility check is only required for signalling braking distances on the higher speed line.

Where trains join a higher speed line at a converging junction from a lower speed line or start from a siding, loop or another platform line

The compatibility check is only required for signalling braking distances on the higher speed line.

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Signal braking distances on the lower speed line are exempt from the compatibility check

Signal braking distances for train movements from the lower speed line are exempt from the compatibility check

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Guidance on Lineside Signal Spacing and Speed Signage

Situation

c

Where trains start from a platform on a through line

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50% The compatibility check is only required for signalling braking distances associated with non-stopping trains. Signal braking distances for train movements that start from rest are exempt from the compatibility check

d

Where the signal spacing is designed using particular signalling braking distance data (for example, Appendix A for a mixed traffic line)

The compatibility check is only required for signalling braking distances associated with the appendix to which the line is signalled

e

Where the signal spacing is designed to Appendices B or C, and a differential speed restriction is applied to enable traffic with an inferior braking characteristic to operate

The compatibility check is only required for signalling braking distances associated with the appendix to which the line is signalled

f

At the approach to buffer stops at terminal stations or at bay platforms

The compatibility check does not apply to the spacing distance between the approach signals and the buffer stops

Table 1 Exemptions from the compatibility check Note:

2.2

Further guidance GN42 to GN50 is provided in 2.4 on the topic of acceptable variations in signal spacing addressed in this Table 1, which is reproduced from GK/RT0075. For ease of reference, extracts from Table 1 have been reproduced in this Guidance Note.

Requirement for signal spacing 2.2.1

The position of lineside signals shall be compatible with the braking performance of rolling stock so that trains moving at the permissible speed (or attainable speed in the circumstances set out in 2.7) can stop within the actual signalling braking distance.

GN01

The signalling system provides information to the driver by means of the aspects displayed, to identify that the train is approaching the end of its movement authority.

GN02

The cautionary aspects should be displayed at a sufficient distance on the approach to the signal where the train is required to stop, so that the train can brake from the permissible speed using a full service brake application and stop at the signal.

GN03

Inadequate signal spacing between the first cautionary aspect and the end of the movement authority could be a causal factor of a signal passed at danger (SPAD), if the train cannot stop before reaching the end of its movement authority.

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Guidance on Lineside Signal Spacing and Speed Signage GN04

The signal spacing between the first cautionary aspect and the end of the movement authority should take account of the permissible speeds and braking performance of all trains that operate over the route. If appropriate, use may be made of differential permissible speeds, in order to optimise the signal spacing for trains with different braking characteristics (see 2.3.4 and 2.3.5).

GN05

The requirements for signal aspect sequences approaching the end of a movement authority are set out in GK/RT0045.

2.3

Determining minimum signalling braking distances 2.3.1

Minimum signalling braking distances shall be determined using the data in Appendices A to C, as set out in 2.3.3 to 2.3.5. The associated guidance note (GK/GN0675) contains signalling braking distance data in imperial (yards) as well as metric units. Additionally, in respect of Appendices A, B and C, these data are included in graphical form.

2.3.2

Additional requirements for assessing compatibility of the data used and rolling stock performance are set out in 2.1.2.

GN06

The infrastructure manager is responsible for deciding which signalling braking distance data to use for each line of route.

GN07

The decision is taken at the scheme development stage and should take account of: a)

All types of rolling stock to be operated over the route by each railway undertaking, including braking performance information.

b)

The speeds at which trains are to be operated by each railway undertaking.

GN08

The railway undertakings operating trains over the route should provide the information to the infrastructure manager about rolling stock types, braking performance and train speeds.

GN09

The processes set out in GE/RT8270: Assessment of Compatibility of Rolling Stock and Infrastructure should be used to check compatibility between rolling stock and the signalling system before: a)

New or modified trains are introduced onto the network.

b)

Any changes are made to the signalling system which could affect the ability of any trains to stop within the available signalling braking distances.

c)

Railway undertakings operate any trains at speeds higher than that previously allowed.

GN10

The infrastructure register and rolling stock register (required by the Interoperability Regulations) may be referred to when managing changes.

GN11

Railway Group Standards GM/RT2041: Braking System Requirements and Performance for Trailer Coaching Stock, GM/RT2042: Braking System Requirements and Performance for Traction Units, GM/RT2043: Braking System and Performance for Freight Trains and GM/RT2044: Braking System Requirements and Performance for Multiple Units, specify the braking performance of rail vehicles that is compatible with the signal spacing derived from the data in Appendices A, B and C of GK/RT0075.

GN12

The rolling stock standards specify the braking rates that the trains are designed to achieve. They include various allowances and contingencies to cater for variation in operational performance (for example, errors in speed, and the potential reduction in the available braking rate due to partial failure of the braking system). However, these standards only specify the stopping distance to be achieved on level track; the

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Guidance on Lineside Signal Spacing and Speed Signage corresponding stopping distances for different gradients, which are used in determining minimum signal spacing, are only specified in the appendices to GK/RT0075. 2.3.3

The minimum signalling braking distance shall be established from Appendix A, based on the maximum permissible speed for freight trains (taking account of standard differential speeds and speed limits imposed by special instructions).

GN13

GK/RT0075 Appendix A is based on the braking rates specified in GM/RT2041 Figure 1, GM/RT2042 Figure 1, GM/RT2043 Figure 1 and GM/RT2044 Figure 1. These are the minimum braking rates specified for rolling stock (referred to in GM/RT2041 etc as the ‘V’ curve).

GN14

Trains that do not conform to these minimum requirements (for example, engineering trains or abnormal freight loads) are operated only in accordance with special operating rules, which are a condition of allowing them to operate on the network. 2.3.4

Where passenger trains (including those with enhanced braking where specific non-standard differentials are not provided) are authorised to travel at speeds greater than the permissible freight train speed (by means of standard or nonstandard differential speeds), the signalling braking distance shall be equal to or exceed the distance derived from Appendix B, for the maximum permissible speed of those trains.

GN15

GK/RT0075 Appendix B is based on the braking rates specified in GM/RT2041 Figure 2, GM/RT2042 Figure 2 and GM/RT2044 Figure 2. These are the standard braking rates for all types of passenger rolling stock (often referred to as the ‘W’ curve). Below 100 mph this curve is based on the friction characteristic of cast-iron brake blocks.

GN16

Appendix B is used to determine the signal spacing on lines where it is advantageous to optimise the signal spacing for passenger train operations and either: a)

It is acceptable to impose differential speeds to limit the speed of trains that do not meet the braking performance of Appendix B, or

b)

Only trains which meet the braking performance of Appendix B normally operate and it is acceptable either to prohibit the operation of trains which do not meet the braking performance of Appendix B, or to permit such trains to operate only under special operating procedures.

GN17

Where Appendix B is used to establish the signal spacing, the infrastructure manager should also consider the signal spacing required by trains that do not meet the braking performance of Appendix B, unless no such trains are permitted to operate on the line, or impose differential speed restrictions to ensure that the signal spacing is adequate for these trains also to stop, from the lower speed, within the distance available.

GN18

Where it is proposed to resignal a line using Appendix B (or Appendix C) on a route where a differential speed restriction for certain types of trains is currently imposed by an operational rule without the provision of differential speed signs (for example the ‘twothirds’ rule for freight trains), and the minimum signal spacing does not provide adequate stopping distance for trains operating at a differential speed in accordance with the existing rule, one of the following solutions should be applied:

GN19

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a)

Provide differential speed signs showing the differential speed determined in accordance with GN17 above, or

b)

Use Appendix A, which is compatible with all trains.

In particular, it should be noted that the existing ‘two-thirds’ rule which has been applied to limit the speeds of freight trains on lines of the former Southern Region was based on Page 11 of 103 GK/GN0675 Issue Four September 2015

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Guidance on Lineside Signal Spacing and Speed Signage signalling set out in Appendix D of GK/RT0034 (now withdrawn), which provided adequate signal spacing for freight trains travelling at two-thirds of the speed set out in Appendix D. The minimum signalling braking distances in Appendix B may not provide adequate spacing at all speeds and gradients for freight trains travelling at two-thirds of the permissible speed, and thus the provisions of GN18 may need to be applied. GN20

Differential speeds may be imposed for reasons other than restricted signal spacing. For instance, it may be possible to take advantage of differential permissible speeds imposed for other reasons, to optimise the signal spacing in relation to the speed profile and braking capability of different types of trains. The infrastructure manager should record the reason for the imposition of the differential speed, for instance in the Sectional Appendix or an attachment to it. 2.3.5

Where passenger trains with enhanced braking are authorised to travel at speeds greater than the permissible freight train speed (by means of nonstandard differential speeds), the signalling braking distance shall be equal to or exceed the distance derived from Appendix C, for the maximum permissible speed of passenger trains with enhanced braking.

GN21

GK/RT0075 Appendix C is based on the braking rates specified in GM/RT2041 Figure 3, GM/RT2042 Figure 3 and GM/RT2044 Figure 3. These are the enhanced braking rates achieved by certain types of passenger rolling stock (referred to in GM/RT2041 etc as the ‘Y’ curve, and sometimes referred to as the ‘9%g curve’).

GN22

Appendix C is used to determine the signal spacing on lines where it is advantageous to optimise the signal spacing for trains meeting the enhanced braking performance of Appendix C and either: a)

It is acceptable to impose differential speeds to limit the speed of trains that do not meet the braking performance of Appendix C, or

b)

It is acceptable either to prohibit the operation of trains which do not meet the braking performance of Appendix C, or to permit such trains to operate only under special operating procedures.

GN23

The use of Appendix C for low/medium speed mixed traffic lines should be avoided as the speed differentials are generally excessive.

GN24

Where Appendix C is used to establish the signal spacing, the infrastructure manager should also consider the signal spacing required by trains that do not meet the braking performance of Appendix C (unless no such trains are permitted to operate on the line) and impose differential speed restrictions to ensure that the signal spacing is adequate for these trains also to stop, from the lower speed, within the distance available.

GN25

Differential speeds may be applied using non-standard differential permissible speed indicators (see 3.3.2.1) showing a higher speed for a category of train which applies only to trains with braking compatible with Appendix C (for example HST).

GN26

Where differential speeds are applied using non-standard differential permissible speed indicators (see 3.3.2.1) showing a category of train which is not restricted to trains with braking compatible with Appendix C (for example MU or SP), Appendix C can be used to determine the signal spacing for trains running at the speed indicated on these signs only if means are taken to ensure that only those trains with braking compatible with Appendix C are permitted to run at this speed. If other trains in this category, which do not have braking compatible with Appendix C, are permitted to run on the line, they must be restricted to lower speeds, for example by an instruction in the Sectional Appendix.

GN27

Where it is proposed to resignal a line using Appendix C on a route where a differential speed restriction for certain types of trains is currently imposed by an operational rule

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Guidance on Lineside Signal Spacing and Speed Signage without the provision of differential speed signs, the minimum signal spacing may not provide adequate stopping distance for trains operating at a differential speed in accordance with the existing rule. When this is the case, one of the following solutions should be applied: a)

Use differential speed signs in place of the operational rule, or

b)

Change the operational rule to impose speeds compatible with the actual signalling braking distance, or

c)

Reposition the signal to provide the signalling braking distance compatible with the existing operational rule.

GN28

Some changes to differential speeds have to be applied in conjunction with changes to entries in the ‘Route Clearance Table’ in the Sectional Appendix. For example, multiple unit differentials can only be used for Appendix C signal spacing if non-9%g braked multiple units are restricted.

GN29

Differential speeds may be imposed for reasons other than restricted signal spacing. For instance it may be possible to take advantage of differential permissible speeds imposed for other reasons, to optimise the signal spacing in relation to the speed profile and braking capability of different types of trains. The infrastructure manager should record the reason for the imposition of the differential speed, for instance in the Sectional Appendix or an attachment to it. 2.3.6

GN30

The minimum signalling braking distance shall be determined using: a)

The permissible speed at the signal displaying the first cautionary aspect, and

b)

The average gradient of the line between the signals displaying the first cautionary aspect and the stop aspect.

2.3.7

For gradients between two values shown in the tables, the signalling braking distance for that gradient shall be calculated by linear interpolation between the signalling braking distances for the two adjacent gradient values.

2.3.8

Where a falling gradient varies and the mean gradient is 1 in 200 or steeper, the minimum signalling braking distance to be used shall be the shorter of either: a)

The distance for the mean gradient plus 10% of that distance, or

b)

The distance for the steepest falling gradient.

There are two SPAD traps associated with falling gradients: a)

Where the gradient steepens on the final approach to the end of movement authority.

b)

Where an initial rising gradient is followed by a steep falling gradient.

In both cases because the driver may not be able to initiate a brake application at the caution aspect sufficient to bring the train to a stand at the red, the provision of a reminder (for instance a lineside sign or banner repeating signal) should be considered, located at the commencement of the more steeply falling gradient. GN31

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Locations which include combinations of rising and falling gradients, both steeper than 1 in 100, within the distance between the first caution and the associated stop signal, require special consideration. Each case should be considered separately in relation to the performance of trains authorised to operate on the route, to ensure that signals are spaced to enable all such trains to be stopped safely. Page 13 of 103 GK/GN0675 Issue Four September 2015

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Guidance on Lineside Signal Spacing and Speed Signage 2.4

Acceptable variations in signal spacing 2.4.1

GN32

The position of signals shall be designed so that the actual signalling braking distance is no less than the minimum signalling braking distance.

The signalling should be designed such that the distance from the first caution aspect to the limit of movement authority, for each train travelling at its permissible speed, should be not less than the signalling braking distance quoted in the relevant appendix (A, B or C) to this document. 2.4.2

Wherever practicable, the position of signals shall be designed so that excess signalling braking distance does not exceed 50%.

GN33

It is good practice to design signal positions with some excess spacing over the minimum required so that drivers do not have to use the full service brake in order to stop at signals. Also, some variation in actual signal spacing arises because signals have to be positioned to provide good sighting, and positioned appropriately in relation to stations, junctions and other constraining features. This also allows for adjustment of the signal positions to cater for sighting difficulties or other constraints not fully identified at the initial design stage.

GN34

Excessive signal spacing may be a causal factor of a SPAD. Ideally, the first cautionary aspect identifies the point at which the driver should apply the brake.

GN35

If the distance between the first cautionary aspect and the end of the movement authority is significantly greater than the distance required for braking, drivers may not apply the brake at the cautionary aspect, but may delay braking until they reach a point that they judge to be the required braking point. This could potentially lead to a driver error in judging the position that the brakes need to be applied, resulting in a SPAD. 2.4.3

Additional requirements for assessing compatibility of actual signalling braking distances and train operations, where there is more than 50% excess signalling braking distance, are set out in 2.1.3.

GN36

Signals should, wherever possible, be positioned with no more than 50% excess over the minimum spacing distance. However, there are circumstances where excess spacing greater than 50% may be preferable to the alternatives.

GN37

Nevertheless, it may be necessary to accept excessive signal spacing if its avoidance would result in signals being positioned such as to be non-compliant with other requirements.

GN38

Whereas inadequate signal spacing significantly increases the likelihood of a SPAD, and is therefore unacceptable, excessive signal spacing is only one of a number of potential factors that can lead to an increased risk of a SPAD.

GN39

On a route where rolling stock operates with differing permissible speeds and braking characteristics, the degree of excess in respect of a particular signal may vary widely between different trains, and this should be reflected in the professional driving policies of railway undertakings that operate over the routes concerned.

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Guidance on Lineside Signal Spacing and Speed Signage GN40

GN41

GN42

Where the excess signal spacing exceeds 50%, the infrastructure manager should assess the SPAD risk arising from excessive signal spacing, taking account of the balance of the various factors, including: a)

Factors that contribute to a SPAD risk (see below).

b)

Factors that mitigate the SPAD risk (see below).

The assessment of SPAD risk should include (but not be limited to) the following factors: a)

Driver distraction (particularly between the caution signal and the point where trains need to start braking).

b)

Signal sighting.

c)

Aspect sequences.

d)

Signal spacing and location.

e)

Junction signalling controls.

f)

Effect of rising and/or falling gradients.

g)

Effect of intervening changes in permissible speed.

Table 1 sets out a number of circumstances where it is often not practicable to avoid excess spacing greater than 50%. Guidance on each of these circumstances is addressed in the following extracts:

Situation

a

Where signals control movements in the same direction on parallel lines that have different permissible speeds, and signals are positioned adjacent to each other to minimise the risk of driver misread or disregard

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50% The compatibility check is only required for signalling braking distances on the higher speed line. Signal braking distances on the lower speed line are exempt from the compatibility check

Table 1 extract (a) Parallel lines GN43

GK/RT0045 includes a requirement to position signals on parallel lines adjacent to each other to minimise the risk of misreading, even when this results in excess spacing on the slower speed line. Where there are parallel lines with different signal spacing requirements (due to different permissible speeds), the excess signal spacing on a slower line is a secondary issue to the requirement in GK/RT0045.

GN44

Where there are parallel fast and slow lines and 4-aspect signalling is provided on the fast lines, 3-aspect signalling at the same spacing may provide adequate signalling braking distance for trains at the slower maximum permissible speed applicable on the slow lines. However, if provision of this arrangement requires extension of the signalling braking distance to provide the required spacing for the 3-aspect signalling on the slow line and this results in excess signal spacing for the 4-aspect signalling on the fast line, the excess signal spacing on the fast line should be subject to a risk assessment. In addition, the risk assessment should consider the alternative of providing 4-aspect signalling on both fast and slow lines.

RSSB

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Guidance on Lineside Signal Spacing and Speed Signage

Situation

b

Where trains join a higher speed line at a converging junction from a lower speed line or start from a siding, loop or another platform line

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50% The compatibility check is only required for signalling braking distances on the higher speed line. Signal braking distances for train movements from the lower speed line are exempt from the compatibility check

Table 1 extract (b) Converging lines GN45

Where trains join a through line from another line, including from a siding, loop or platform, and the permissible speed through the connection is lower than that on the through line, the signal spacing is determined using the higher permissible speed on the through line. This may result in excess signal spacing in relation to the lower speed of trains on the connecting line.

Situation

c

Where trains start from a platform on a through line

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50% The compatibility check is only required for signalling braking distances associated with non-stopping trains. Signal braking distances for train movements that start from rest are exempt from the compatibility check

Table 1 extract (c) Starting from platforms GN46

Where trains may start from rest (for example, from a station platform on a through line), the signal spacing is determined by trains running through the station at permissible speed. This results in excess signal spacing when considered in relation to the lower speed of trains starting from rest.

Situation

d

Where the signal spacing is designed using particular signalling braking distance data, (for example, Appendix A for a mixed traffic line)

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50% The compatibility check is only required for signalling braking distances associated with the appendix to which the line is signalled

Table 1 extract (d) Trains with better braking characteristics GN47

Wherever trains with different braking capabilities (conforming to the different appendices of GK/RT0075) operate, except where differential speeds are used to match the different

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Guidance on Lineside Signal Spacing and Speed Signage braking performances to the signal spacing, the signal spacing is determined by the trains with the lowest braking rate. This results in excess signal spacing when considered in relation to the required braking distance for trains with better braking performance.

Situation

e

Where the signal spacing is designed to Appendices B or C, and a differential speed restriction is applied to enable traffic with an inferior braking characteristic to operate

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50% The compatibility check is only required for signalling braking distances associated with the appendix to which the line is signalled.

Table 1 extract (e) Differential permissible speeds GN48

Where the signalling system is optimised for a particular type of operation (for example, passenger), in most cases the differential permissible speed is determined by the reduced signal spacing and should be compatible with the excess signal spacing requirements.

GN49

Where a lower differential permissible speed is applied for other reasons (for example, axle load), it is not necessary to consider trains restricted to a lower permissible speed than that required to conform to the signal spacing requirements.

Situation

f

At the approach to buffer stops at terminal stations or at bay platforms

Scope of compatibility check where actual signal spacing exceeds the minimum signalling braking distance by more than 50% The compatibility check does not apply to the spacing distance between the approach signals and the buffer stops.

Table 1 extract (f) Terminal platforms GN50

2.5

GN51

RSSB

On lines where the minimum signalling braking spacing is less than 500 m, a maximum signalling spacing distance of 1000 m is permitted, subject to a compatibility/risk assessment as set out in 2.1.3. Where signals are closely spaced, speeds will be moderate and drivers will probably be able to see several signals ahead at the same time.

Consistency of signalling braking distances 2.5.1

Variation in the excess signalling braking distances between successive signals shall be kept to a minimum in order to control the risk associated with signals passed at danger (SPAD).

2.5.2

Additional requirements for assessing compatibility of variation of excess signalling braking distances and train operations are set out in 2.1.3.

Variation in excess signal spacing is also a causal factor of a SPAD risk. A particular risk may arise where one or more signal sections with a large excess of spacing are followed by a signal section with little or no excess. Large variations in signal spacing, when combined

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Guidance on Lineside Signal Spacing and Speed Signage with minimum yellow to red distance in a four aspect sequence (see 2.6) can be particularly hazardous. GN52

Existing good practice has established a desirable limit for the maximum variation of 34% in excess signal spacing between successive signals, above which a risk assessment is required to determine whether there is an unacceptable increase in SPAD risk. Any relaxation in this limit would need to be justified. The distance between a red-green stop signal and the next isolated distant signal is not relevant as it is not involved in braking.

GN53

At locations where there is a reduction in permissible speed from one signal section to the next, the required signal spacing between successive signals reduces. Thus, the actual signal spacing between one signal section and the next may reduce substantially without any significant variation in excess spacing. While this does not fall within the scope covered by 2.5.1, requiring a SPAD risk assessment, it should be recognised that there may still be a potential SPAD risk, particularly if the reduction in spacing is not expected, and any potential risk should still be considered.

GN54

On the approach to a major terminal station, or other significant area where permissible speeds are low, the reduction in actual signal spacing is more likely to be expected by the driver and therefore SPAD risk may be less.

2.6

Four-aspect signalling 2.6.1

In areas of 4-aspect signalling, the distance between the single yellow aspect and the red aspect shall be no less than one-third of the actual signalling braking distance between the double yellow aspect and the red aspect, unless the criteria set out in either 2.6.2 or 2.6.3 apply.

GN55

Variation in the distance between consecutive signals in a 4-aspect sequence may be misleading to drivers. A particular SPAD risk may arise where the distance from the single yellow to the red aspect is significantly less than the distance from the double yellow to the single yellow aspect. This could lead to the driver not reducing speed adequately before passing the single yellow aspect and not expecting the red aspect to be so close. It should be noted that this is a case of inconsistency of signal spacing (see 2.5 above).

GN56

To avoid this potentially misleading situation, the preferred arrangement set out in 2.6.1, (as shown in GN Figure 1) requires the distance from the single yellow aspect to the red aspect to be at least one-third of the actual signalling braking distance between the double yellow aspect and the red aspect. This means that the distance from the single yellow to the red aspect should not be less than half the distance between the double yellow aspect and the single yellow aspect. Minimum signalling braking distance (YY-R) [MSD] Actual signalling braking distance 101-105 [ASD] ≥⅓ ASD

101

103

105

GN Figure 1 Spacing of 4-aspect signals – preferred arrangement (see 2.6.1)

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Guidance on Lineside Signal Spacing and Speed Signage 2.6.2

It is permissible for the distance between the single yellow aspect and the red aspect to be reduced to no less than one-third of the required minimum signalling braking distance between the double yellow aspect and red aspect.

GN57

Section 2.6.2 permits a relaxation of the arrangement set out in 2.6.1, subject to an assessment of the additional SPAD risk arising. This permits the distance between the single yellow and the red aspect to be reduced to one-third of the minimum required signalling braking distance, as shown in GN Figure 2.

GN58

If the actual distance between the double yellow and the red aspect includes an excess over the minimum signalling braking distance, this may result in the distance from the single yellow to the red aspect being less than half the distance between the double yellow and the single yellow. The risk assessment should consider any additional risk of a SPAD which may be introduced by this arrangement.

Minimum signalling braking distance (YY-R) [MSD] Actual signalling braking distance 101-105 [ASD] ≥⅓ MSD

101

105

103

GN Figure 2 Spacing of 4-aspect signals – alternative arrangement (see 2.6.2) GN59

Where two or more consecutive double yellow aspects are displayed in the aspect sequence approaching a signal at red (see GK/RT0045), the actual signalling braking distance between the single yellow aspect and the red aspect should not be less than onethird of the minimum required signalling braking distance between the first cautionary aspect and the red aspect (as set out in 2.6.2) as shown in GN Figure 3. It is likely that this will be greater than one-third of the actual signalling braking distance between the inner double yellow and the red (since the reason for providing consecutive double yellow aspects is generally that the inner double yellow is less than the required minimum spacing distance from the red aspect).

GN60

Where two or more consecutive single yellow aspects are displayed in the aspect sequence approaching a signal at red (see GK/RT0045), the constraints set out in this section should be applied to the distance between the outer single yellow aspect and the red aspect.

Minimum signalling braking distance (YY-R) [MSD] ≥⅓ MSD

99

101

103

105

GN Figure 3 Spacing of 4-aspect signals with consecutive double yellows RSSB

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Guidance on Lineside Signal Spacing and Speed Signage 2.6.3

2.6.4

GN61

It is permissible for mid-platform signals to be located so that the distance from the single yellow aspect at the mid-platform signal to the red aspect at the platform starting signal is less than one-third of the required minimum signalling braking distance between the double yellow aspect and the red aspect. In this case the permissible speed and the location of the mid-platform signal shall be configured to comply with all of the following requirements: a)

The distance between the running-in platform ramp and the platform starting signal is greater than the minimum signalling braking distance at the permissible speed.

b)

The mid-platform signal is sighted so that it is visible to the driver from the running-in platform ramp, as set out in GE/RT8037.

c)

The platform starting signal is sighted so that it is visible to the driver from the mid-platform signal, as set out in GE/RT8037.

Additional requirements for assessing compatibility of four-aspect signal spacing and train operations are set out in 2.1.2.

Section 2.6.3 permits a further relaxation of the ‘one-third rule’ set out in 2.6.1 and 2.6.2 at stations, subject to the specific conditions stated. This arrangement (shown in GN Figure 4) is applicable only at stations where the permissible speed for through trains is low, since the distance between the running-in platform ramp and the platform starting signal should be greater than the minimum braking distance at the permissible speed. While this arrangement contravenes the principle set out in the preceding sections, by allowing what could be an unexpectedly short distance between the single yellow and the red aspect, this is mitigated by the visibility requirements stated. Minimum signalling braking distance (YY-R) at speed PS1 MSD] Actual signalling braking distance 101-105 [ASD] ≥ Minimum braking distance at speed PS2 May be <⅓ MSD

101

Permissible speed = PS1

103

105

Permissible speed = PS2

PLATFORM

GN Figure 4 GN62

Spacing of 4-aspect signals at station with mid-platform signal

If this relaxation was not permitted, and it was not possible to meet the spacing requirements set out in 2.6.1 or 2.6.2 in respect to the distance between the mid-platform signal and the platform starting signal, a standard YY-Y-R aspect sequence up to the platform starting signal would not be possible. The alternative arrangement which would have to be implemented would require a (YY)-Y-R sequence up to the mid-platform signal at red, which could then be approach released to single yellow to allow the train to continue to the platform starting signal. This arrangement would have the disadvantage of requiring a cautionary (double yellow) aspect to be shown at an earlier signal than necessary. It also introduces an additional risk, since the aspect sequence approaching the station would be the same whether the train is to stop at the mid-platform signal or the platform starting signal. If drivers are expecting to be allowed to proceed to the starting signal when the train is in fact required to stop at the mid-platform signal, they may expect and anticipate the clearance of the mid-platform signal as they approach it, resulting in a SPAD if it remains at danger.

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Guidance on Lineside Signal Spacing and Speed Signage 2.7

Use of attainable speed to determine minimum signal spacing 2.7.1

Where attainable speed is used to determine minimum signalling braking distances, the maximum attainable speed shall be derived using current acceleration data for the appropriate types of rolling stock. Additional requirements for assessing compatibility of minimum signalling braking distances and rolling stock performance are set out in 2.1.2.

GN63

Where attainable speed is used to determine signal spacing, the infrastructure manager should review all types of rolling stock that operate over the route to ensure that the greatest possible acceleration rate is identified and used. GE/RT8270 sets out the requirements and responsibilities for assessing the compatibility between rolling stock and infrastructure assets, including control, command and signalling equipment and their operations.

GN64

Where differential permissible speed limits apply, it is permissible for these to be taken into account when determining the required signalling braking distances.

GN65

Where attainable speed is used to determine signal spacing, consideration should be given to making this attainable speed a permanent speed restriction (PSR) and signing it accordingly. 2.7.2

On a 4-aspect signalled line, at a converging junction, the distance between the first signal beyond the junction and the next stop signal shall be compatible with both of the following: a) The permissible speed and aspect sequence through the junction on the straight route. b) The permissible speed and aspect sequence on the converging route.

GN66

Where a connection onto a 4-aspect signalled line has a permissible speed which is lower than the permissible speed on the through line, the attainable speed at the signal beyond the connection should be used to determine the required signal spacing between that signal and the next stop signal.

GN67

If the distance provides adequate signal spacing for a train travelling at the attainable speed, the signal on the converging line on the approach to the connection may be a 3-aspect signal. An example is shown in GN Figure 5. This can apply where the converging line is a running line with 3-aspect signalling or a bay platform, siding or depot exit line.

201

Attainable speed at X for train from converging line = 50 mph ≥ Minimum signalling braking distance at attainable speed (50 mph)

101

Permissible speed through junction = 30 mph

103

105

X

GN Figure 5 Use of attainable speed at signal beyond converging junction GN68

Where the spacing from the signal beyond the connection to the next stop signal does not provide adequate spacing for a train travelling at the attainable speed, the signal before the connection on the converging line should be a 4-aspect signal.

RSSB

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Guidance on Lineside Signal Spacing and Speed Signage 2.7.3

Where the converging route is a 3-aspect signalled line and the permissible speed through the convergence is lower than the permissible speed on the straight route, one of the following shall apply: a) The attainable speed at the first (4-aspect) signal beyond the junction (taking account of any permissible speed restriction through the junction) shall be compatible with the actual signalling braking distance to the next signal so that the train can stop when the signal is displaying a single yellow aspect, or b) The last signal on the converging route shall be a 4-aspect signal.

GN69

Where the converging line is a crossover from a parallel line with 3-aspect signals, it is undesirable to provide an isolated 4-aspect signal at the junction solely for moves over the crossover. Particular care is therefore needed in the positioning of the first signal beyond the crossover to ensure that a movement onto the 4-aspect line is not underbraked. Permissible arrangements, allowed by GK/RT0045 are: a)

Provide a minimum signalling braking distance for the attainable speed from 103 to 105, as set out in GN Figure 5.

b)

Imposing a lower permissible speed over the crossover to ensure that the attainable speed at 103 is compatible with the minimum signalling braking distance from 103 to 105. Although this is undesirable, it is considered preferable to the provision of an isolated 4-aspect signal on the slower speed line.

c)

Control the aspect of 103, so as to give a caution aspect at 201.

2.7.4.

GN70

Where there is signalling braking distance from the commencement of an existing reduction of permissible speed and the stop signal, it is permissible to use the attainable speed at the first caution.

In GN Figure 6, the YY is not at the required signal braking distance for 125 mph, but the 25 mph lower permitted speed imposes a speed at the YY sufficient to stop at the red signal without the need for an additional warning indicator. MSD 25

125

25

25

P

GN Figure 6 Showing the use of assessed speed approaching a signal

2.8

Requirements at infrastructure manager boundaries 2.8.1

GN71

The requirements for signal spacing set out in this document shall apply also to the transitions between different signalling systems that are part of Network Rail managed infrastructure.

This covers transitions between conventional lineside signalling and other signalling systems, including cab-signalling [Transmission Voie-Machine (TVM), European Train Control System (ETCS)], as well as transitions to other forms of lineside signalling (such as metro-type signalling) which do not conform to the signal spacing requirements set out in GK/RT0075.

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Guidance on Lineside Signal Spacing and Speed Signage 2.8.2

Where a signalling braking distance crosses a boundary between infrastructure managers, the minimum distance between a caution signal and the associated stop signal (or equivalent end of movement authority) shall be determined using the signalling braking criteria specified by the infrastructure manager controlling the stop signal (or responsible for the end of movement authority).

GN72

The principle is that the signal spacing for the aspect sequence leading up to a stop signal should always be determined in accordance with the requirements applicable to that stop signal, as determined by the infrastructure manager who controls it, regardless of the ownership of the preceding signals which provide the cautionary aspects.

GN73

There may be variations in requirements arising from the different types of rolling stock using the line. For example, requirements for Network Rail signals leading up to a London Underground (LUL) controlled stop signal differ between those locations where main line trains (conforming to the braking characteristics set out in the appendices to GK/RT0075) run onto the LUL line, and those locations where only LUL trains (conforming to LUL braking standards) use the LUL line.

RSSB

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Guidance on Lineside Signal Spacing and Speed Signage Part 3 3.1

Guidance on Requirements for Signing of Permissible Speeds and Speed Restrictions Compatibility requirements for signing of permissible speeds and speed restrictions 3.1.1

GE/RT8270 sets out the process for the assessment of compatibility that is required whenever a material change is to be made that affects the interface between the signalling system and railway undertakings or any infrastructure managers that operate stations.

3.1.2

The assessment of compatibility shall check that permissible speeds and temporary speed restrictions are compatible with existing and planned train operations on each route, including a check of all of the following:

3.1.3

a)

The permissible speed profile.

b)

The configuration and position of permissible speed indicators and permissible speed warning indicators.

c)

The provision of additional speed signs, where this is a permitted option to manage operational risk, including: i)

Additional permissible speed warning indicators (see 3.3.1).

ii)

Repeater permissible speed indicators at converging junctions (see 3.3.3).

d)

Where the nature of engineering work results in complex signage arrangements. The propose configuration and position of temporary speed indicators and warning boards and the arrangements for their implementation and withdrawal.

e)

The configuration and position of signs that display standard and nonstandard differential speeds, where trains compatible with the signalling braking distances set out in Appendices B and C are authorised to operate at higher permissible speeds (see 3.3.2).

f)

The omission of differential speed signs, where differential speeds are implemented by instruction (see 3.3.1).

g)

The display of metric speed information, where this is required (see 3.2.1).

h)

The overall presentation of information to the driver (further requirements are set out in 3.2.2).

The assessment of compatibility shall check that the deceleration distances (see 3.2.3) used, which are the minimum spacing distances between the warning indicator and the speed indicator, are compatible with all of the following: a)

The types of rolling stock that will be operated on the route.

b)

The maximum speeds that the rolling stock will be authorised to operate on the route.

c)

The maximum attainable speeds of rolling stock, where these are used to determine the signal spacing.

d)

The permissible speed(s) on every signalled approach to the speed reduction, including differential speeds which are authorised for different types of rolling stock.

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Guidance on Lineside Signal Spacing and Speed Signage e) The speed reduction(s) required on every signalled approach. f)

The applicable speed restriction, including differential speeds.

g) The average gradient on the approach to the speed indicator/board. GN74

The consultation in respect of permissible speed signing should cover all permanent arrangements for the application of, or changes to, speed restrictions and the associated signs. Consultation should include the use of signal sighting committees to agree the position and sighting of permissible speed signs (see 3.3.1.1).

GN75

It is not practicable for the infrastructure manager to consult with the railway undertaking(s) in respect of the implementation and withdrawal of all temporary speed restrictions. However, consultation should be carried out in cases of complex engineering work, particularly where the configuration and positioning of signs could be confusing to drivers or could create a risk of misunderstanding.

3.2

Requirements for permissible speeds and temporary speed restrictions

3.2.1

Display of speed information 3.2.1.1 The infrastructure manager shall provide lineside operational safety signs to display permissible speeds and temporary speed restriction information, applicable to each running line, for each direction that trains can be operated under signalled movement authorities for main running movements. 3.2.1.2

Speed signs shall display speed information in units of miles per hour.

3.2.1.3

Where trains are operated using speedometers calibrated in kilometres per hour, speed signs shall also display speed information in units of kilometres per hour.

3.2.1.4

Speed signs that display differential speeds shall display the lower (or lowest) speed above the higher speed(s).

3.2.1.5

Speed signs shall be positioned on the left-hand side of the line in the direction of travel, unless they cannot be accommodated there.

3.2.1.6

Speed signs shall be configured so that all applicable speeds (including differential speeds) over the same section of track are displayed together at the same position and location. It is permitted for nominally co-located signs to be separated by a short distance where readability would not be impaired.

GN76

Section 3.2 sets out the general requirements for the display of speed information to drivers, including the requirement to provide appropriate speed signs and the position and format of the speed information that is displayed.

GN77

Section 3.3 sets out the provision and positioning requirements for permissible speed signs, including the circumstances in which a permissible speed warning indicator and automatic warning system (AWS) should be provided.

GN78

Section 3.4 sets out the requirements for provision of speed signs in connection with temporary and emergency speed restrictions. Because of the potential complexity associated with implementation of temporary and emergency speed restrictions, the detailed requirements for the positioning of the speed signs are set out in the following appendices: a)

RSSB

Appendix D sets out the positioning requirements for speed signs on plain line areas and at junctions.

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Guidance on Lineside Signal Spacing and Speed Signage b)

Appendix E sets out the requirements for emergency speed restrictions.

GN79

Speed signs always display speeds in units of miles per hour because these are the units by which the railway is currently operated and signed in lineside signalled areas. Where trains are operated using speedometers calibrated in kilometres per hour and lineside speed signs are required, the speed signs should additionally display speed information in units of kilometres per hour because drivers have to correlate the speed information displayed at the lineside with the speed information displayed on the speedometer.

GN80

Where dual speed signage in mile/h and km/h would result in a multiplicity of signs, compatibility should be checked in accordance with 3.2 1 above.

3.2.2

Overall presentation of information to the driver 3.2.2.1 Speed signs and associated automatic warning system (AWS) equipment shall be positioned so that the totality of information (including lineside signs, signal aspects, indications and lineside equipment) displayed to the train driver is not liable to cause confusion. 3.2.2.2

GN81

3.2.3

Where train protection systems are in use, the position of speed signs shall be compatible with the warning and intervention functionality of these systems so that a driver obeying the lineside signs does not receive unwarranted warnings or interventions.

In some complex layouts, strict application of all the requirements in this standard may not achieve the objective of providing clear and unambiguous information to the driver. In such cases, the infrastructure manager should seek an alternative solution, which meets this objective. Possible solutions include: a)

Alterations to the proposed geographical limits of the permissible speeds or speed restrictions.

b)

Alterations to the speed value(s) of the permissible speeds or speed restrictions.

c)

Alteration to the signalling arrangements.

Deceleration distances 3.2.3.1 Where attainable speed is used to determine the deceleration distance (only permitted for temporary speed restrictions), the maximum attainable speed shall be derived using current acceleration data for the appropriate types of rolling stock. Additional requirements for assessing compatibility of deceleration distances and rolling stock performance are set out in 3.1.3.

GN82

Permissible speed warning indicators are only necessary for some reductions in permissible speed, where the required speed reduction meets the criteria set out in 3.3.1.4.

GN83

Warning boards should be provided on the approach to all temporary speed restrictions. (Exceptions are permitted as set out in GK/RT0075, 3.4.1.4.)

GN84

Permissible speed warning indicators and temporary speed restriction warning boards should be positioned at a sufficient distance on the approach to the point where the reduced speed commences, to ensure that each train can brake from its permissible speed, using normal service braking rate, to achieve the required speed reduction. The permissible speed for certain trains may be limited by: a)

Differential speed limits.

b)

Maximum speeds applicable to particular types of train.

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Guidance on Lineside Signal Spacing and Speed Signage c) GN85

Other speed restrictions applied by instruction (for example, the two-thirds rule for freight trains in operation on former Southern Region lines).

Every type of train authorised to operate over the route should be considered where differential speeds apply, including the following speed transition combinations: a)

One differential speed to another differential speed.

b)

A standard speed to a differential speed.

c)

A differential speed to standard speed.

3.2.3.2

Where differential speeds are associated with a speed reduction to a lower permissible speed or a temporary speed restriction (whether they are applicable to the permissible speed on the approach, the lower permissible speed or temporary speed restriction, or both), the deceleration distance shall be determined for each type of train, taking account of: a)

The applicable speeds for that train, and

b)

The longest deceleration distance required.

GN86

Where differential speeds apply, all applicable combinations of differential approach speed and differential speed restriction should be considered so that the correct speed differentials are used to determine the required deceleration distance.

GN87

There may be circumstances in which a different type of train with better braking performance is to be operated over an existing route (for example, a train compatible with Appendix C, which is to be operated on a route signalled to Appendix A). In this case the braking performance of the train should be checked against the signalling braking distances and the position of speed signs, before an increased speed is authorised.

GN88

The higher permissible speed should be signed as a differential speed unless all other trains that may be operated over the route are also compatible with the signalling braking distances and the position of speed signs.

GN89

GE/RT8270 sets out the procedure to be followed between the railway undertaking and the infrastructure manager to enable the latter to verify the braking performance of trains that are authorised to operate on any given route.

3.2.3.3

RSSB

Deceleration distances shall be determined using one of the following: a)

The deceleration data set out in Appendix X, which is compatible with Appendix A (composite data for all trains).

b)

The signalling braking distance, where minimum signalling braking distances have been determined using Appendix B (composite data for passenger trains), and the deceleration distance derived from Appendix X is greater than the minimum signalling braking distance.

c)

The signalling braking distance, where minimum signalling braking distances have been determined using Appendix C (data for trains with enhanced braking), and the deceleration distance derived from Appendix X is greater than the minimum signalling braking distance.

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Guidance on Lineside Signal Spacing and Speed Signage GN90

The deceleration distances set out in Appendix X are compatible with the train braking performance used to determine the signalling braking distances in Appendix A. Use of the distances in Appendix X, therefore, provides adequate deceleration distances for all trains.

GN91

Deceleration tables for trains with higher braking rates (based on the braking performance used to determine the signalling braking distances in Appendices B and C) have not been published. On lines where signalling braking distances are based on Appendices B or C, the deceleration distance set out in Appendix X for some speed reductions is greater than the required signal spacing (from the first caution aspect to a signal at danger).

GN92

Where the signalling braking distance set out in Appendices B or C for the applicable approach speed is less than the deceleration distance set out in Appendix X, the appropriate signalling braking distance from Appendices B or C should be used as the required deceleration distance, instead of the distance set out in Appendix X.

3.2.3.4

Appendices B or C shall only be used to determine deceleration distances for permissible speeds and temporary speed restrictions where all of the trains that operate over the route have a braking performance that is compatible with the required reduction in speed, taking account of the following factors: a)

The permissible speed, including enhanced permissible speeds and differential speeds, and

b)

The authorised speed limits applicable to each category and type of train.

GN93

Signalling braking distances from Appendices B or C should be used as deceleration distances only for the types of trains, for which those signalling braking distances are applicable.

GN94

Trains with a lower braking performance (that is to say, compatible with Appendix A) may be restricted to a maximum operating speed that is lower than the permissible speed on the approach to the warning indicator or warning board, even where differential speed restrictions are not specifically applied. Where this is the case, the deceleration distance should be based on signalling braking distances from Appendices B or C, for trains approaching at a higher speed, provided that this also gives sufficient deceleration distance in accordance with Appendix X, for trains to which Appendix A is applicable at their maximum operational speed. Similar considerations apply to trains restricted to a speed that is lower than the permissible speed for other reasons, for example, freight trains that are limited to 75 mph.

GN95

Where differential speeds apply on the approach to a reduction in speed, and the higher approach speed requires a higher braking rate in order to conform to the required speed reduction, the higher speeds should only apply to those categories of trains which have the required braking performance.

GN96

The maximum attainable speed should only be used to determine the deceleration distance for temporary speed restrictions where none of the rolling stock authorised to use the line is capable of achieving the permissible speed (or the differential permissible speed applicable to that type of train).

GN97

Attainable speed should not be used to determine the deceleration distance approaching reductions in permissible speed. Instead, the designed permissible speeds should be compatible with the attainable speed of trains.

GN98

Since the use of attainable speed is applicable only to temporary speed restrictions, it is not generally practicable for the infrastructure manager to request validated acceleration data from the railway undertakings for each specific application.

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Guidance on Lineside Signal Spacing and Speed Signage 3.3

Signs for permissible speeds

3.3.1

Position and sighting of signs 3.3.1.1 A signal sighting committee (as set out in GE/RT8037) shall agree the position and sighting of:

GN99

a)

Permissible speed indicators.

b)

Permissible speed warning indicators.

The positioning and sighting of signs for permissible speeds should be agreed by signal sighting committees. These signs should be considered in the context of the overall arrangement of signals and operational signs. 3.3.1.2

Permissible speed indicator(s) shall: a)

Display the relevant speed(s).

b)

Be provided for every increase or decrease of permissible speed, except where differential speeds applying to certain types of train are implemented by instruction. This applies where speed is required to be restricted for particular types of train that do not constitute a recognised category for which differential speed signs are specified in the Rule Book.

c)

Be positioned where the change of permissible speed occurs (see Figure 1).

40 90

40

Figure 1 Example of a permissible speed indicator GN100

Where differential speeds apply (see 3.3.2), there may be a change in permissible speed at a particular location for some categories of trains, but not for others. In this case a permissible speed sign should be provided, which displays all the differential speeds.

GN101

In some circumstances, speed restrictions are imposed using operating instructions, instead of lineside signs. Typically, these speed restrictions may be associated with: a)

Specific train movements (for example, degraded operations).

b)

Axle load criteria associated with particular vehicle types.

c)

Defined classes of train (for example, the ‘two-thirds’ rule – see GN19).

GN18 sets out additional guidance on determining signalling braking distances where differential speed restrictions are imposed using operating instructions. GN102

RSSB

On sections of line where it is not possible for trains to achieve the maximum permissible speed, for example on the approach to a reduction in permissible speed or immediately beyond an increase in permissible speed, the infrastructure manager should determine appropriate maintenance requirements based on the maximum attainable speed on that section of line. Where attainable speeds are used solely to determine maintenance specifications, it is not necessary to advise these speeds to drivers as changes in permissible speed, and in this case they will not be shown either in the Sectional Appendix or on lineside signs.

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Guidance on Lineside Signal Spacing and Speed Signage 3.3.1.3 3.3.1.4

Permissible speed indicators shall be provided at converging and diverging junctions in accordance with 3.3.3 and 3.3.4. Except where the criteria in 3.3.1.5 apply, a permissible speed warning indicator shall be provided on all signalled approaches to each permissible speed reduction, where either: a)

The permissible speed on the approach, including any differential speed, is 60 mph or greater and the required speed reduction is one-third or more, taking account of any differential permissible speeds that apply, or

b)

There are two or more successive reductions in permissible speed within a distance of 3.2 km (2 miles), none of which individually represents a reduction of one-third, but which together require a speed reduction of one-third or more from an approach speed of 60 mph or greater (see Figure 2). < 3.2 km (2 miles)

125

90

125

65

P 90

65 90

50

65 Note:

50

Depending on spacing of speed reductions and relevant deceleration distances, the warning indicator for the second speed reduction could fall before the speed indicator for the first speed reduction

Figure 2 Example of two or more successive reductions in speed

GN103

The criteria for provision of permissible speed warning indicators and associated AWS magnets (sometimes referred to as the ‘Morpeth rules’) were introduced following a number of incidents where drivers entered a section of line with a severe speed restriction at excessive speed, in some cases leading to derailment. The criteria are intended to ensure that drivers cannot approach a severe speed reduction without being aware of it.

GN104

Where differential speeds apply, either on the approach to a speed reduction or to the speed beyond the reduction, the speed reduction applicable to each category of train should be considered. A permissible speed warning indicator is required when any category of train has a permissible approach speed of 60 mph or greater and a required speed reduction of one-third or more.

GN105

The additional criteria set out in 3.3.1.4b) apply where there is a series of successive speed reductions, each of which, considered individually, does not come within the conditions of 3.3.1.4a), but together still result in a risk of a driver approaching a low-speed area at excessive speed.

GN106

See 3.3.5.3 and 3.3.5.4 for further details of the positioning of the permissible speed warning indicators in these cases.

GN107

Additional permissible speed warning indicators may be provided for speed reductions falling outside the criteria of 3.3.1.4, where this increases safety and does not cause confusion to drivers. Such provision should be applied consistently on each section of route.

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Guidance on Lineside Signal Spacing and Speed Signage 3.3.1.5

Permissible speed warning indicators shall not be provided for: a)

A speed reduction over a diverging route where the signalling system is configured to display signal aspects that provide for the required speed reduction (see 3.3.7).

b)

A speed reduction over a level crossing where a Level Crossing Warning Sign (St Georges Cross) is provided.

GN108

Where a junction signal is approach controlled from red for a diverging route, the aspect sequence may be used to inform the driver of the need to control the speed of the train approaching the divergence. In this case, a permissible speed warning indicator would not provide any additional value and is not required. The driver should use route knowledge of the permissible speed at the divergence.

GN109

Where the speed reduction required for a divergence is within the criteria of 3.3.1.4, and an aspect sequence other than approach control from red is used for the diverging route, a permissible speed warning indicator is used to advise the driver of the necessary speed reduction. See 3.3.7 for further details. 3.3.1.6

GN110

Detailed requirements concerning the positioning of permissible speed warning indicators, for simple cases and for diverging routes, are set out in 3.3.5, 3.3.6 and 3.3.7. 3.3.1.7

GN111

3.3.2

RSSB

Where provided, permissible speed warning indicators shall be positioned in accordance with 3.3.5, 3.3.6 and 3.3.7, using the appropriate deceleration distance set out in 3.2.3.3.

Only one permissible speed warning indicator shall be provided on each approach to a permissible speed indicator, unless an additional indicator is required to mitigate safety risk and will not cause confusion to drivers. Further requirements are set out in 3.1.2.

To avoid confusion, a train should normally only pass one permissible speed warning indicator associated with a particular permissible speed indicator. Section 3.3.6 sets out the arrangement normally provided at converging junctions to achieve this. Display of differential permissible speeds 3.3.2.1 Permissible speed indicators and permissible speed warning indicators shall display a maximum of three differential speeds (applicable to different categories of trains), including standard and non-standard differential speeds. For the purposes of this section, an enhanced permissible speed as defined in GE/RT8012 shall be considered as a non-standard differential speed. The only permitted combinations are: a)

Two displayed speeds, each for one of two standard categories of train, where standard differential speeds apply.

b)

One displayed speed for a standard category of train and either one or two displayed non-standard speeds applicable to the train categories set out in GE/RT8000 Rule Book module SP.

c)

Two displayed speeds for the two standard categories of train (standard differential speeds), together with one displayed non-standard differential speed applicable to a train category set out in GE/RT8000 Rule Book module SP.

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Guidance on Lineside Signal Spacing and Speed Signage 3.3.2.2

Further requirements applicable to differential speeds are set out in 3.1.2.

3.3.2.3

Where standard differential speeds apply, the two speeds shall be displayed on a single permissible speed indicator (see Figure 3) and, where a warning indicator is provided, on a single permissible speed warning indicator (see Figure 4).

20 50

90

20/50

Figure 3 Example of a standard differential permissible speed indicator

20 50

Figure 4 Example of a standard differential permissible speed warning indicator

GN112

‘Standard’ differential speeds are shown on speed indicators and warning indicators by two speed values, one above the other (see 3.2.1.4), without any specific indications to identify particular categories of trains. The bottom figure (which shows the higher speed) applies to passenger trains (loaded or empty), parcels and postal trains (loaded or empty), and light locomotives; the top figure (which shows the lower speed) applies to all other trains.

GN113

The arrangement for displaying ‘standard’ differential speeds, with the lower speed value shown by the top figure and the higher speed value by the bottom figure: a)

Provides a consistent display.

b)

Means that the lower speed value, which is a safe speed for all trains, should be read first by the driver.

3.3.2.4

Non-standard differential permissible speeds shall be displayed by a separate speed sign, which shall incorporate an indication of the applicable train category. The meanings of letter abbreviations for non-standard speeds are set out in Rule Book Module SP. The classes of train that apply in a given situation are set out in the Sectional Appendices.

3.3.2.5

A non-standard permissible speed indicator shall be mounted on the same post as the associated standard permissible speed indicator (see Figure 5) and: a)

Where the non-standard speed is higher than the standard speed(s), it shall be displayed below the standard speed(s).

b)

Where the non-standard speed is lower than the standard speed(s), it shall be displayed above the standard speed(s).

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Guidance on Lineside Signal Spacing and Speed Signage HST 90 60 90

60/90

HST 50 90 75 90

50/75/90

CS 90 75 90

75/90

Figure 5 Examples of a non-standard differential permissible speed indicator 3.3.2.6

Where a permissible speed warning indicator is required, non-standard differential speeds shall be displayed by a separate speed sign, which shall incorporate an indication of the applicable train category. Further requirements about train categories are set out in GE/RT8000 Rule Book.

3.3.2.7

A non-standard permissible speed warning indicator shall be mounted on the same post as the standard permissible speed warning indicator (see Figure 6) and: a)

Where the non-standard speed is higher than the standard speed(s), it shall be displayed below the standard speed(s).

b)

Where the non-standard speed is lower than the standard speed(s), it shall be displayed above the standard speed(s).

HST 90 60

HST 50 90 75

90

Figure 6

CS 75

Examples of a non-standard differential permissible speed warning indicator

GN114

‘Non-standard’ differential speeds are shown on speed indicators and warning indicators by an additional speed value on a separate sign, with additional letters above the speed value that identify the category of train to which the speed applies. The letters used to indicate the different categories of trains are set out in the Sectional Appendices.

GN115

Most non-standard differential speeds (for example, HST, MU, SP) apply to categories of trains that are permitted to travel at a higher speed than the standard permissible speed(s)

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Guidance on Lineside Signal Spacing and Speed Signage applying at that location. The sign showing a non-standard differential speed that is higher than the standard permissible speed(s) is placed on the same post, but below the standard speed indicator, for the same reason that this arrangement is used for signing of standard differential speeds (see 3.3.2.3). GN116

There are cases where a non-standard differential speed (for example, CS) applies to a particular category of train that is required to travel at a lower speed than the standard permissible speed(s) applying at that location. In this case the sign showing a nonstandard differential speed that is lower than the standard permissible speed(s) is placed above the standard speed indicator.

3.3.3

Permissible speed indicators at converging junctions 3.3.3.1 A permissible speed indicator shall be provided at converging junctions if the permissible speed beyond the converging junction is different from the permissible speed on the higher speed route (see Figure 7). 20 70

90 90

Figure 7 Example of permissible speed indicator at converging junction

GN117

A permissible speed indicator is provided so that the different permissible speed beyond the converging junction is displayed to all trains after they have passed the junction.

3.3.3.2

It is permissible to provide a miniature permissible speed indicator as a repeating sign immediately after a converging junction, where all of the following apply: a)

The permissible speed beyond the junction is the same as the permissible speed of the approach on the higher speed route, and

b)

The permissible speed beyond the junction is higher than that on the converging route, and

c)

The junction is not located within the deceleration distance approaching a lower speed for which warning has already been given.

GN118

A miniature permissible speed sign positioned immediately beyond a converging junction may be provided for operational performance purposes.

GN119

A miniature speed indicator is considered sufficient for use as a repeating sign because it is not critical for the driver to observe the higher permissible speed and it is only relevant to the train approaching from the converging route.

GN120

The decision on whether to use a miniature permissible speed sign involves co-operation between the infrastructure manager and railway undertakings in assessing the compatibility between the signage arrangements and train operations.

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Guidance on Lineside Signal Spacing and Speed Signage 3.3.4

Permissible speed indicators at diverging junctions 3.3.4.1 A permissible speed indicator with an arrow indicating the direction of the diverging (lower speed) route shall be provided immediately before a diverging junction (including a facing crossover) over which there is a reduction in permissible speed (see Figure 8). Where the permissible speed of the straight route does not change at the junction, a speed indicator shall not be provided for the straight route.

50

50

90

90

Figure 8 Example of permissible speed indicator at diverging junction with speed reduction on diverging route only

GN121

A permissible speed indicator with an arrow applies only to the diverging route (or routes) in the direction indicated by the arrow. Where only an indicator with an arrow is provided, drivers understand that the permissible speed on the straight route does not change at the junction.

GN122

Where a position light junction indicator is provided, the direction of the arrow should correspond with the orientation of the indicator. This is particularly important where the speed over the straight route is lower than that over the diverging route.

3.3.4.2

Where a lower permissible speed applies equally to both routes, a single permissible speed indicator shall be provided without directional arrows (see Figure 9).

40 90

40 40

Figure 9 Example of permissible speed indicator at diverging junction with speed reduction (equal speed) on both routes

GN123

It is not necessary to provide a permissible speed indicator at a diverging junction where the permissible speed through the junction is the same for all routes, and is the same as the permissible speed that applies on the approach to the junction. Typically, this applies in low-speed areas such as on the approach to a large station. 3.3.4.3

RSSB

Where different permissible speeds commence for each route at a diverging junction or crossover, two permissible speed indicators shall be positioned side-by-side. Arrow(s) shall be incorporated into the sign to indicate any divergence (see Figures 10 and 11).

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Guidance on Lineside Signal Spacing and Speed Signage 40 90

40 90

125

Figure 10

Example of permissible speed indicator at diverging junction with speed reduction on both routes (different speeds) 40

40

50 125

50

Figure 11 Example of permissible speed indicator at diverging junction with no straight route GN124

Permissible speed signs applying to different routes should be placed side-by-side, not vertically on the same post. This is so that drivers do not interpret the indicated speeds as differential speeds for the same route.

GN125

Where space is limited and it is not practicable to position the signs side-by-side, a signal sighting committee may decide to position the two signs one after the other.

3.3.5

Positioning of permissible speed warning indicators 3.3.5.1 Where provided, permissible speed warning indicators shall: a)

Be positioned as close as practicable to (but not less than) the deceleration distance from the permissible speed indicator taking account of the longest deceleration distance required (see Figure 12), and

b)

Not be positioned between a signal or other sign applicable in the same direction of travel and the AWS equipment associated with that signal or sign. DD 70–40 P

40 70

40 70

40

Figure 12 Example of permissible speed warning indicator (simple case)

GN126

Section 3.3.1.4 sets out the circumstances in which a permissible speed warning indicator is required to be provided.

GN127

The permissible speed warning indicator should provide sufficient deceleration distance for all types of trains. Where differential speeds apply, the longest deceleration distance applies.

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Guidance on Lineside Signal Spacing and Speed Signage GN128

The longest required deceleration distance may be significantly greater than the distance required by some trains, and this is acceptable.

GN129

The distance between the permissible speed warning indicator and the speed indicator may need to be increased to provide adequate sighting, or to avoid AWS conflicts or positions where it is not practicable to site the warning indicator.

3.3.5.2

Where two permissible speed indicators are located at the same position (for example, at a diverging junction) and permissible speed warning indicators are required for both, the position of the permissible speed warning indicators shall be determined using the greatest deceleration distance required.

GN130

If speed indicators are at the same position, the associated warning indicators should also be at the same position; if the speed indicators are in different places the warning indicators should be considered separately for each. It is not acceptable to have warning indicators at different locations applying to permissible speed indicators at the same location, since this could be misleading to drivers. However, it is permitted for nominally co-located signs to be separated by a short distance, as permitted by 3.2.1.6, where space is limited.

GN131

Where a warning indicator is required only for the lower speed diverging route, and the speed reduction for the higher speed route is not great enough to require a warning indicator to be provided, it is permissible to provide the warning indicator only for the lower speed (diverging) route.

GN132

Where the speed reduction required for a diverging route is enforced by the signalling system approach releasing the junction signal from red (see 3.3.1.5 and 3.3.7.1), a warning indicator is not provided for the speed on the diverging route. Where there is also a speed reduction on the straight route which commences at the same point and requires a warning indicator, the warning indicator should be provided only for the speed reduction on the straight route with no warning indicator for the speed reduction on the diverging route.

3.3.5.3

Where the circumstances set out in 3.3.1.4b) apply, the deceleration distance used to position the permissible speed warning indicator shall be determined using the permissible speed applicable prior to the commencement of the series of reductions in speed (see Figure 13).

< 3.2 km (2 miles) 125 125

90

65

P 90

65 90

DD 125-65

Figure 13

RSSB

65

50 50

Note: depending on spacing of speed reductions and relevant deceleration distances, warning indicator for second speed reduction could fall before speed indicator for first speed reduction

Example of permissible speed warning indicator for successive reductions in speed

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Guidance on Lineside Signal Spacing and Speed Signage GN133

The criteria for provision of permissible speed warning indicators and associated AWS magnets (see 3.3.1.4) are intended to ensure that drivers cannot approach a severe speed reduction without being an AWS warning. If the driver fails to respond to the warning, the AWS applies the brakes.

GN134

Where a series of successive speed reductions apply, as shown in Figure 13, the first speed reduction (from 125 mph to 90 mph) is not considered severe enough to cause a significant risk of derailment if the driver continues at the approach speed (125 mph), and therefore a warning indicator is not provided. Similarly, if the driver correctly reduces speed to 90 mph but fails to observe the further reduction to 65 mph, the risk from overspeeding is again small. It is only if the driver fails to observe both reductions in speed, and continues at the approach speed (125 mph) into the second (lower) speed restriction (65 mph), that a significant risk arises.

GN135

To provide protection against this possibility, the permissible speed warning indicator (and associated AWS) for the second speed reduction to 65 mph are positioned to provide deceleration distance from the initial approach speed of 125 mph. This should enable drivers (or the AWS brake application if they fail to respond) to reduce speed to 65 mph before reaching the start of the 65 mph restriction, even if they have failed to observe the earlier reduction to 90 mph.

GN136

Where application of these criteria (or those in 3.3.5.5), might result in a potentially confusing arrangement of signs, for instance where the warning indicator for a reduction in speed would be required to be positioned before the speed indicator for a previous reduction in speed, consideration should be given to providing a warning indicator (with AWS) for the first speed reduction even though the requirements set out in 3.3.1.4 do not apply.

3.3.5.4

Where further permissible speed reductions occur beyond a reduction for which a permissible speed warning indicator and associated AWS magnet is provided, these shall be assessed separately. A further permissible speed warning indicator shall be provided if the criteria set out in 3.3.1.4 are met (see Figure 14). < 3.2 km (2 miles) 125

P

80

125

80 125 DD 125–80

80

65 65

P

50

50

65

50

DD 80–50

Figure 14 Example of successive reductions in speed where a further permissible speed warning indicator is required

GN137

The principle applied in 3.3.5.3 is extended to cover further reductions in speed, based on the assumption that the driver responds to the speed reduction for which a warning indicator and AWS are provided.

GN138

Therefore, in Figure 14 it is assumed that the driver has responded to the reduction from 125 mph to 80 mph (for which a warning indicator and AWS are provided). The subsequent reduction from 80 mph to 65 mph, even if it is within the two-mile zone, is assessed in relation to an approach speed of 80 mph, and therefore does not require a warning indicator. The further reduction from 65 mph to 50 mph is also assessed for an approach speed of 80 mph (since no warning indicator was provided for the reduction to 65 mph), and the warning indicator for this should be located to provide the required deceleration distance from 80 mph to 50 mph.

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Guidance on Lineside Signal Spacing and Speed Signage 3.3.5.5

Where exceptionally the speed profile is such that the deceleration distance would either: a)

Position a permissible speed warning indicator within a section of line with a lower permissible speed than that immediately preceding the speed reduction (see Figure 15), or

b)

Encompass a section of line with a lower permissible speed (see Figure 16), and this lower speed is equal to or less than the speed displayed on the permissible speed warning indicator, one of the following arrangements shall be used:

c)

The permissible speeds shall be adjusted to avoid this arrangement (preferred), or

d)

The permissible speed warning indicator shall be positioned at the end of the lower speed section, beneath the permissible speed indicator for the higher speed (non-preferred).

DD 70–40 40 125

Figure 15

40

40

40 70

40

40

70

40

Example of positioning of permissible speed warning indicator where deceleration distance falls within lower speed section

DD 70–40 40

30 30

40 70

40

125

125

70

40

Figure 16

Example of positioning of permissible speed warning indicator where deceleration distance encompasses lower speed section

Note The arrangements shown in Figures 15 and 16 are non-preferred. Where practicable, permissible speeds should be specified to obviate such arrangements.

GN139

RSSB

In the example shown in Figure 15, the deceleration distance from 70 mph to 40 mph is longer than the length of line to which the 70 mph permissible speed applies, and this would position the warning indicator within the previous 40 mph section. In this case the 40 mph warning indicator is placed at the end of the previous 40 mph section, below the 70 mph permissible speed indicator. This should provide adequate warning to drivers, who should then accelerate only to a speed from which they can decelerate back to 40 mph before reaching the start of the subsequent 40 mph section.

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Guidance on Lineside Signal Spacing and Speed Signage GN140

In the example shown in Figure 16, the deceleration distance from 70 mph to 40 mph is again longer than the length of line to which the 70 mph permissible speed applies; in addition it would extend through the previous 30 mph section into the preceding section of line on which the permissible speed is 125 mph. However, as trains are restricted to 30 mph in the intervening section, placing the 40 mph warning indicator at the end of the 30 mph section, below the 70 mph permissible speed indicator, provides adequate warning to drivers to accelerate only to a speed from which they can decelerate back to 40 mph.

GN141

In the above cases it may not be appropriate to sign the intermediate section for 70 mph, particularly where this section is short and it is not possible for any trains to accelerate to this speed before decelerating again to the 40 mph restriction. The signed speed should be compatible with the acceleration and braking performance of trains.

3.3.5.6

If the permissible speed on the preceding lower speed section is higher than the permissible speed displayed on the permissible speed warning indicator and there is an intermediate higher permissible speed, the permissible speed warning indicator shall be positioned either: a)

At not less than the deceleration distance, or

b)

At the end of the lower speed section, beneath the permissible speed indicator for the higher speed

whichever is the greater distance. In this case the intermediate higher permissible speed shall be disregarded when determining the position of the permissible speed warning indicator. 3.3.5.7

Further requirements for checking the provision, position and configuration of permissible speed warning indicators are set out in 3.1.2.

GN142

Where the deceleration distance for the preceding lower speed would position the permissible speed warning indicator within the intermediate higher speed section, the permissible speed warning indicator should be positioned below the permissible speed indicator for the higher speed section, as set out in 3.3.5.5. This provides adequate warning to drivers, who should then accelerate only to a speed from which they can decelerate to the appropriate speed before reaching the start of the permissible speed restriction for which the warning indicator applies.

GN143

Where the deceleration distance for the preceding lower speed requires the permissible speed warning indicator to be positioned within the lower speed section, the warning board should be placed at not less than the deceleration distance.

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Guidance on Lineside Signal Spacing and Speed Signage 3.3.6

Permissible speed warning indicators at converging junctions 3.3.6.1 Where the criteria set out in 3.3.1.4 apply at converging junctions, permissible speed warning indicators shall be provided: a)

On each signalled approach to a permissible speed indicator (see Figure 17).

b)

So that all approaching trains receive one warning for each permissible speed reduction. 90

P

40

DD 90–40 P

40

125

40 125

DD 125–40 Note: 125 repeater sign omitted intentionally (3.3.3.2 refers)

Figure 17 Example of permissible speed warning indicators at converging junction

GN144

It is undesirable for a driver to pass more than one warning indicator for the same permissible speed indicator. Therefore, if the deceleration distance required for the higher speed approach places the warning indicator before a converging junction, the warning for a lower speed approach should also be placed before the converging junction.

GN145

In the example shown in Figure 17, the deceleration distance for the lower speed approach (90 mph to 40 mph) also requires the warning board to be placed before the converging junction.

GN146

If the speed on the lower speed approach was such that the deceleration distance for this speed would place the warning board on the main line beyond the converging junction, the warning board should still be placed on the approach to the converging junction, so that it is not passed by a train on the main line that has already passed a warning board for the same speed indicator.

3.3.7

Permissible speed warning indicators at diverging junctions 3.3.7.1 A permissible speed warning indicator incorporating a directional arrow shall be provided to indicate a permissible speed on a diverging route over or beyond a diverging route ahead, where:

GN147

RSSB

a)

The junction signal is not approach controlled from red (see GK/RT0045), and

b)

The required speed reduction meets the criteria set out in 3.3.1.4

Except where approach control of the junction signal from red enforces a reduction in speed, a warning indicator is required for the speed reduction over a diverging junction where it meets the normal criteria for provision of a warning indicator.

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Guidance on Lineside Signal Spacing and Speed Signage 3.3.7.2

Where a permissible speed warning indicator incorporating a directional indication is positioned at a signal that displays a cautionary aspect for the diverging route to which the warning indicator applies: a)

The caution indication given by the AWS magnet associated with the signal shall also apply to the warning indicator.

b)

A separate AWS magnet shall not be provided for the warning indicator (see Figure 18).

> DD 125–40 Not approach controlled from red

40

40 125

40 125

Figure 18 Example of permissible speed warning indicator for diverging junction positioned at a signal that displays a cautionary aspect

GN148

It is good practice to locate the permissible speed warning indicator, applying to a diverging route, at a signal which displays a cautionary aspect for the diverging route (see GK/RT0045).

GN149

In this case the same AWS inductor gives a caution indication for the signal and the warning indicator. This has the following advantages:

GN150

a)

It avoids the need for suppression of the AWS, which would be required for a separate AWS magnet (see 3.3.7.3).

b)

The driver receives information about the turnout speed, to supplement the signal aspect which advises him of the diverging route.

It is permissible for the warning indicator to be located at either the outer (flashing YY) or the inner (flashing Y) signal, depending on the required deceleration distance. If the deceleration distance is less than the Y to R spacing, the preferred arrangement is to locate the warning indicator at the inner signal.

3.3.7.3

GN151

Where a permissible speed warning indicator incorporating a directional indication is not positioned at a signal that displays only a cautionary aspect for the diverging route to which the warning indicator applies: a)

A separate AWS magnet shall be provided for the permissible speed warning indicator, and

b)

The AWS magnet shall be suppressed when the junction signal and any intervening signals between the permissible speed warning indicator and the junction signal have been cleared for a route for which the warning indicator does not apply.

Except where the arrangement of 3.3.7.2 is applied, a separate AWS magnet should be provided to alert the driver to the permissible speed warning indicator for the diverging route.

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Guidance on Lineside Signal Spacing and Speed Signage GN152

Except where the arrangement of 3.3.7.2 is applied, the AWS magnet associated with the speed warning indicator for the diverging route is suppressed when the signals have been cleared for the straight route at the junction, to avoid giving the driver an AWS caution indication which is not applicable when the train is approaching the junction under green signals.

GN153

When the signal at the junction has not been cleared for either route, an AWS caution indication is received. As this is associated with a permissible speed warning indicator incorporating a directional arrow, the driver should understand that this only applies to the diverging route ahead.

3.3.7.4

A permissible speed warning indicator, incorporating a directional arrow, shall be positioned adjacent to the permissible speed indicator (with directional arrow) at a diverging junction, or crossover (see Figure 19) where: a)

A reduction in permissible speed on the diverging route beyond the diverging junction (or crossover) requires a permissible speed warning indicator; or

b)

The deceleration distance would position the permissible speed warning indicator in the vicinity of the diverging junction or crossover; or

c)

Either it is not practicable to locate the warning indicator within the diverging junction or crossover, or it is necessary to make it clear to which line the warning indicator applies.

20 60 90

20 60

> DD 60–20 60

Figure 19 Example of permissible speed warning indicator for speed reduction on a diverging route

GN154

Where the deceleration distance would position the permissible speed warning indicator in the vicinity of a crossover, the arrangement shown in Figure 19 should be applied because it is not normally practicable to position a speed sign part way through a crossover.

GN155

Because the warning indicator with directional arrow is located adjacent to the permissible speed indicator (also with a directional arrow), which indicates the speed through the crossover, drivers should understand that the warning indicator applies to a further speed restriction on the diverging route beyond the crossover.

GN156

This warning indicator is not positioned on the approach side of the permissible speed indicator, because drivers would interpret the warning indicator with a directional arrow as an indication of the speed through the diverging route at the crossover (as set out in 3.3.7.1), rather than a speed restriction beyond the crossover.

GN157

If the speeds and distances shown in Figure 19 are such that the deceleration distance approaching the 20 mph speed indicator would require the warning indicator for the move through the crossover to be situated before the crossover, a possible solution would be to reduce the speed through the crossover, such that the deceleration distance is reduced to equal to, or less than, the distance between the crossover and the speed indicator. The arrangement shown in Figure 19 could then be applied.

RSSB

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Guidance on Lineside Signal Spacing and Speed Signage 3.3.8

GN158

Provision of AWS magnets for permissible speed warning indicators 3.3.8.1 An AWS magnet shall be provided on the approach to all permissible speed warning indicators provided to satisfy the criteria set out in 3.3.1.4, except a)

Where the AWS magnet associated with a signal displaying a cautionary aspect is configured to provide an equivalent warning (see 3.3.7.2).

b)

On lines not fitted with AWS.

c)

In AWS gap areas.

d)

In respect of additional warning indicators.

The AWS system should be configured so that a caution indication is given to the driver on the approach to every permissible speed warning indicator, except as shown above. 3.3.8.2

The AWS magnet shall: a)

Be positioned 180 m on the approach to the permissible speed warning indicator.

b)

Be positioned not less than 4 seconds running time from any other AWS equipment.

c)

Not be positioned between any other AWS equipment and its associated signal, board or indicator.

The constraints in b) and c) do not apply to other AWS equipment which is provided for movements in the opposite direction and which is suppressed for movements in the direction to which the permissible speed warning indicator applies.

GN159

GE/RT8075: AWS and TPWS Interface Requirements permits the distance from the AWS magnet to the permissible speed warning indicator to be reduced to a minimum of 3 seconds running time. This accounts for the 1 second delay after passing over the permanent magnet before the AWS equipment gives a warning indication and provides the driver with a minimum of 2 seconds to respond to the AWS indication, observe the speed sign and acknowledge the warning.

GN160

The 4 seconds requirement in 3.3.8.2b) is necessary so that the AWS receiver has time to reset, and be ready to respond correctly to the next AWS magnet following a caution indication, which could be acknowledged at the end of the acknowledgement delay period.

GN161

It is important that each AWS indication is directly associated with the signal or indicator that the driver is approaching, which means that AWS magnets provided in connection with permissible speed warning indicators should not be positioned between any other AWS magnet and the equipment associated with it.

3.3.8.3

The AWS magnet shall be configured to generate an AWS caution indication in the driving cab.

3.3.8.4

The AWS magnet shall be suppressed for signalled running movements for which it does not apply, unless AWS cancelling indicators are provided (see GE/RT8075).

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Guidance on Lineside Signal Spacing and Speed Signage GN162

Where independent AWS equipment is provided on the approach to a permissible speed warning indicator (there being no signalled movements in the opposite direction), it should incorporate a permanent magnet only.

GN163

GE/RT8075 specifies the circumstances in which it is acceptable to provide AWS which is not suppressed for signalled movements in the opposite direction, together with AWS cancellation indicators. In these circumstances the AWS magnets provided for permissible speed indicators do not have to be suppressed. In all other cases the AWS magnet should be suppressed for any signalled movements in the opposite direction.

3.3.9

GN164

Publication of alterations of permissible speeds 3.3.9.1 Details of alterations to permissible speeds shall be published in: a)

The Weekly Operating Notice (WON), prior to implementation, and

b)

The next available Periodical Operating Notice (PON), pending re-issue of the appropriate Table A entry in the Sectional Appendix.

GO/RT3215: Requirements for the Weekly Operating Notice, Periodical Operating Notice and Sectional Appendix, sets out the requirements for publication of weekly operating notices, periodical operating notices and sectional appendices. Alterations to permissible speeds are published by the infrastructure manager so that driver route knowledge, with respect to permissible speeds, can be managed by railway undertakings.

3.4

Provision of signs for temporary and emergency speed restrictions

3.4.1

Commencement and termination indicators and warning boards 3.4.1.1 The commencement of each temporary speed restriction shall be indicated by a speed indicator displaying the required speed(s) for all signalled movements entering the speed restriction (see Figure 21), except where: a)

Movements cross over a temporary speed restriction, via a ladder or diamond crossing, and

b)

The permissible speed for the movement via a ladder or diamond crossing is less than or equal to that of the temporary speed restriction (see Figure 20).

110

T

100

Figure 20

GN165

RSSB

20 20

20

110

20

50

Example of movement via crossing not requiring temporary speed restriction signs

Section 3.2.1 mandates provision of speed signs for all speed restrictions, including temporary speed restrictions. Normally, speed indicators should be provided, but where a route via a ladder or diamond crossing already incorporates a permissible speed indicator

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Guidance on Lineside Signal Spacing and Speed Signage that is equal to or less than the temporary speed restriction, a speed indicator is not required. GN166

Figure 20 sets out a typical example where a crossing movement is limited to 20 mph; therefore a 20 mph temporary speed restriction need not be signed for that movement.

3.4.1.2

Except in the case of abutting restrictions (see Appendix D, D.3), a termination indicator, displaying the letter ‘T’, shall be positioned at the end of each temporary speed restriction (see Figure 21).

20

T

Commencement of Speed Restriction Indicator (Speed in mph) Termination of Speed Restriction Indicator

90

20

90

Figure 21 Example of a commencement and termination indicator 3.4.1.3

Speed indicators shall be positioned in accordance with Appendix D.

3.4.1.4

Warning boards shall be provided for all signalled running movements towards temporary and emergency speed restrictions, except where trains always start from rest (for example, a siding or terminal station platform line) and the commencement of the speed restriction is less than 300 m ahead. In these cases the WON shall specify: ‘A warning board is not provided on the ___ line for trains proceeding to the ___ line for the temporary speed restriction at ___ miles ___ chains.’

GN167

GN168

See also the requirements for repeater warning boards set out in Appendix D, D.2.5, which may be provided in some cases for trains starting from rest at a distance of greater than 300 m.

3.4.1.5

Warning boards shall be positioned in accordance with Appendix D, using the deceleration distance criteria in Appendix X.

3.4.1.6

Only one warning board shall be provided on each approach to a temporary speed restriction, except where repeater warning boards are provided in accordance with Appendix D, D.2.5.

To avoid confusion, a train should normally only pass one warning board associated with a particular speed indicator. Appendix D, D.2.2, sets out the arrangement normally provided at converging junctions to achieve this.

Page 46 of 103 GK/GN0675 Issue Four September 2015

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Guidance on Lineside Signal Spacing and Speed Signage 3.4.1.7

Where an emergency speed restriction is to be imposed, an emergency indicator shall be provided in addition to the warning board (see Figure 22), and positioned in accordance with Appendix E.

20 90

90

90

emergency indicator

Figure 22 Example of an emergency indicator

GN169

Emergency speed restrictions are signed in the same way as temporary speed restrictions, with the addition of the emergency indicator and the additional AWS magnet associated with it. This is provided to draw the driver’s attention to the warning board, because details of the speed restriction have not been published in accordance with 3.4.4.

3.4.1.8

3.4.1.9

Speed signs provided for temporary and emergency speed restrictions shall be positioned on the left-hand side of the line in the direction of travel, except where: a)

It is not practicable to accommodate a speed sign on the left-hand side of the line, and

b)

The applicability of a sign positioned on the right-hand side of the line is unambiguous.

Where temporary speed restriction speed indicators or warning boards are positioned to the right of the track in the direction of travel, the WON shall specify either: ‘The temporary speed restriction equipment for trains travelling in the up/down direction on ___ line between ___ miles ___ chains and ___ miles ___ chains is situated to the right of the track,’ or ‘The warning board _________________ (for example, IN THE TUNNEL) on the ___ line at ___ miles ___ chains is situated to the right of the track.’

GN170

Drivers are generally aware of the normal speed profile of a route as part of their route knowledge, and only need to use the permissible speed signs as reminders. In the case of temporary and emergency speed restrictions, drivers are more dependent on the clarity of signage to give them the information they need. It is therefore important that the signs provided for temporary and emergency speed restrictions give clear and unambiguous information about the speed restrictions.

GN171

It is important that the driver understands which line each speed sign applies to, particularly where temporary speed signs are positioned between running lines. The normal position for speed signs is to the left of the line to which they apply, and signs should be placed on the left-hand side wherever practicable.

RSSB

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Guidance on Lineside Signal Spacing and Speed Signage GN172

If signs are placed on the right-hand side of the line on a multiple track railway, it may not be clear to the driver which line they apply to. The driver should, generally, be looking for signs on the left-hand side of the line, and may possibly miss a sign on the right-hand side if it is not drawn to his / her attention.

GN173

Temporary speed restriction signs should only be placed on the right-hand side where their application is clear and the driver has been alerted by the entry in the operating notice.

GN174

As the position of emergency speed restrictions is not published in the WON, there is an increased risk that a driver could miss a sign that is positioned on the right-hand side of the line and therefore this should be avoided wherever possible.

3.4.2

GN175

Display of differential speeds at temporary speed restrictions 3.4.2.1 Speed indicators and warning boards shall only display the two standard differential speeds.

The signs specified for use at temporary and emergency speed restrictions only cater for standard differential speeds (see 3.3.2). Non-standard differential speeds are not displayed at temporary and emergency speed restrictions, to simplify the implementation and publication of these restrictions, which are usually imposed in connection with engineering work or because of infrastructure degradation or failure. 3.4.2.2

The two standard differential speeds shall be displayed (see Figure 23) using: a)

A speed indicator displaying both speeds.

b)

A warning board displaying both speeds.

Differential Speeds (20 over 50)

20 50 90

T

90

20 50 20/50

Figure 23 Example of differential speed indicators

GN176

Standard differential speeds are shown on speed indicators and warning boards by two speed values, one above the other, without any specific indications to identify particular categories of trains. The bottom figure (which shows the higher speed) applies to passenger trains (loaded or empty), parcels and postal trains (loaded or empty), and light locomotives; the top figure (which shows the lower speed) applies to all other trains.

GN177

The arrangement for displaying standard differential speeds, with the lower speed value shown by the top figure and the higher speed value by the bottom figure: a)

Provides a consistent display.

b)

Means that the lower speed value, which is a safe speed for all trains, should be read first by the driver.

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Guidance on Lineside Signal Spacing and Speed Signage 3.4.3

Provision of AWS permanent magnets for temporary speed restriction warning boards 3.4.3.1 An AWS magnet shall be provided on the approach to:

3.4.3.2

a)

All warning boards, in accordance with Appendix D.

b)

All emergency indicators, in accordance with Appendix E.

Except where the criteria in Appendix D, D.2.4 apply, the AWS magnet shall: a)

Be positioned 180 m on the approach to the warning board or emergency indicator.

b)

Be positioned not less than 4 seconds running time from any other AWS equipment.

c)

Not be positioned between any other AWS equipment and its associated signal, board or indicator.

The constraints in b) and c) do not apply to other AWS equipment which is provided for movements in the opposite direction and which is suppressed for movements in the direction to which the permissible speed warning indicator applies. 3.4.3.3

AWS magnet(s) shall be configured to generate an AWS caution indication in the driving cab.

GN178

GE/RT8075 permits the distance from the AWS magnet to the warning board to be reduced to a minimum of three seconds running time. This accounts for the 1 second delay after passing over the permanent magnet before the AWS equipment gives a warning indication and provides the driver with a minimum of 2 seconds to respond to the AWS indication, observe the speed sign and acknowledge the warning.

GN179

The 4 seconds requirement in 3.4.3.2b) is necessary so that the AWS receiver has time to reset and is ready to respond correctly to the next AWS magnet following a caution indication, which could be acknowledged at the end of the acknowledgement delay period.

GN180

Each AWS indication should be directly associated with the signal or indicator that the driver is approaching, which means that AWS magnets provided in connection with warning boards should not be positioned between any other AWS magnet and the equipment associated with it.

3.4.4

Publication of temporary speed restrictions 3.4.4.1 Details of temporary speed restrictions shall be published in the WON prior to implementation. 3.4.4.2

Where this is not practicable, the speed restriction shall be implemented as an emergency speed restriction, as set out in Appendix E.

GN181

GO/RT3215 sets out the requirements for publication of WONs. Details of temporary speed restrictions are published by the infrastructure manager, so that drivers are aware and alert to temporary speed restrictions along the route.

GN182

Where a speed restriction has to be imposed at short notice (for example, as a result of a failure), and it cannot be published in accordance with 3.4.4.1, it should be implemented as an emergency speed restriction (see 3.4.1.7 and Appendix E).

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Guidance on Lineside Signal Spacing and Speed Signage Part 4

Application of this Document

4.1

Application - infrastructure managers

4.1.1

Scope 4.1.1.1

4.1.1.2

The requirements in Part 2 of this document apply to all work that affects the design of new or altered lineside signalling arrangements relating to signal spacing. Where it is known, or becomes known, that existing lineside signal spacing does not comply with the requirements of this document, action to bring it into compliance is required when the signalling is renewed, the signal spacing is modified or permissible speeds are amended. The requirements in Part 3 of this document apply to alterations to the speed profile, including the speed signage for temporary and emergency speed restrictions. Where it is known, or becomes known, that existing lineside speed signage does not comply with the requirements of this document, action to bring it into compliance is required when the speed signage is modified or renewed.

4.1.2

Exclusions from scope 4.1.2.1 There are no exclusions from the scope specified in 4.1.1 for infrastructure managers.

4.1.3

General compliance date for infrastructure managers 4.1.3.1 This Railway Group Standard comes into force and Parts 2 and 3 are to be complied with from 05 December 2015. 4.1.3.2

After the compliance dates or the date by which compliance is achieved if earlier, infrastructure managers are to maintain compliance with the requirements set out in this Railway Group Standard. Where it is considered not reasonably practicable to comply with the requirements, authorisation not to comply should be sought in accordance with the Railway Group Standards Code.

4.1.4

Exceptions to general compliance date 4.1.4.1 There are no exceptions to the general compliance date specified in 4.1.3 for infrastructure managers.

4.2

Application - railway undertakings 4.2.1

4.3

Health and safety responsibilities 4.3.1

GN183

There are no requirements applicable to railway undertakings.

Users of documents published by RSSB are reminded of the need to consider their own responsibilities to ensure health and safety at work and their own duties under health and safety legislation. RSSB does not warrant that compliance with all or any documents published by RSSB is sufficient in itself to ensure safe systems of work or operation or to satisfy such responsibilities or duties.

There is no guidance associated with Part 4.

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Guidance on Lineside Signal Spacing and Speed Signage Appendix A

Signalling Braking Distance Data for all Trains

The content of this appendix is mandatory

A.1

Composite table for all trains (metres) DISTANCE (METRES) GRADIENT (mm/m) Rising INITIAL SPEED (mph)

Falling

20 15 10 5 2.5 (1 in 50) (1 in 67) (1 in 100) (1 in 200) (1 in 400)

Level Level

2.5 5 10 15 20 (1 in 400) (1 in 200) (1 in 100) (1 in 67) (1 in 50)

10

62

65

69

75

78

82

89

97

118

146

190

15

100

107

117

128

136

144

156

168

200

244

311

20

155

165

180

200

210

220

238

255

295

365

480

25

220

235

260

290

303

325

345

375

445

575

770

30

295

315

350

390

418

445

485

530

645

820

1305

35

375

405

445

505

540

585

640

715

925

1265

2046

40

455

505

570

660

730

795

895

990

1300

1740

2046

45

580

650

740

855

945

1035

1185

1315

1520

1740

2046

50

629

684

747

855

945

1035

1185

1315

1520

1740

2046

55

704

760

824

899

955

1035

1185

1315

1520

1740

2046

60

776

833

896

970

1020

1070

1190

1315

1520

1740

2046

65

810

870

938

1019

1066

1116

1220

1315

1520

1740

2046

70

897

961

1033

1117

1165

1218

1280

1353

1520

1740

2046

75

953

1015

1084

1164

1215

1258

1320

1382

1534

1740

2046

80

953

1015

1084

1164

1215

1258

1320

1382

1534

1740

2046

85

1047

1110

1180

1261

1310

1354

1415

1471

1614

1788

2046

90

1181

1254

1334

1428

1485

1537

1610

1674

1842

2049

2330

95

1333

1418

1511

1621

1680

1750

1835

1913

2113

2366

2713

100

1528

1630

1745

1880

1960

2041

2143

2245

2503

2835

3312

105

1528

1630

1745

1880

1960

2041

2143

2245

2503

2835

3312

110

1528

1630

1745

1880

1960

2041

2143

2245

2503

2835

3312

115

1528

1630

1745

1880

1960

2041

2143

2245

2503

2835

3312

120

1585

1655

1745

1880

1960

2041

2143

2245

2503

2835

3312

125

1714

1789

1869

1957

2000

2054

2143

2245

2503

2835

3312

For gradients greater than 1 in 50 rising – use distances for 1 in 50 rising. For gradients greater than 1 in 50 falling – seek derogation.

RSSB

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Guidance on Lineside Signal Spacing and Speed Signage

GN Figure 7 GN184

Composite curves for all trains (metres) GN Figure 7 presents the graphical representation of the data of composite signalling braking distances for all trains in metres.

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Guidance on Lineside Signal Spacing and Speed Signage DISTANCE (YARDS) GRADIENT Rising

Falling

INITIAL SPEED (mph)

2.0% (1 in 50)

10

68

71

75

82

86

90

98

106

129

160

208

15

109

117

128

140

149

158

171

184

219

267

340

20

170

180

195

215

228

240

258

275

320

395

520

25

240

255

280

315

335

355

383

410

485

625

840

30

320

340

380

425

455

485

530

575

700

895

1425

35

405

440

485

550

592

635

707

780

1010

1380

2237

40

495

550

620

720

792

865

972

1080

1420

1903

2237

45

630

710

805

935

1032

1130

1282

1435

1660

1903

2237

50

688

748

816

935

1032

1130

1282

1435

1660

1903

2237

55

770

831

901

984

1057

1130

1282

1435

1660

1903

2237

60

849

911

980

1061

1113

1165

1300

1435

1660

1903

2237

65

886

952

1026

1115

1168

1221

1328

1435

1660

1903

2237

70

981

1051

1129

1222

1276

1331

1405

1479

1660

1903

2237

75

1042

1110

1185

1273

1324

1375

1443

1511

1677

1903

2237

80

1042

1110

1185

1273

1324

1375

1443

1511

1677

1903

2237

85

1145

1214

1290

1379

1430

1481

1545

1609

1765

1956

2237

90

1292

1371

1459

1561

1621

1681

1756

1831

2014

2241

2548

95

1458

1550

1652

1772

1843

1914

2003

2092

2311

2587

2967

100

1671

1783

1908

2056

2144

2232

2343

2455

2737

3100

3622

105

1671

1783

1908

2056

2144

2232

2343

2455

2737

3100

3622

110

1671

1783

1908

2056

2144

2232

2343

2455

2737

3100

3622

115

1671

1783

1908

2056

2144

2232

2343

2455

2737

3100

3622

120

1734

1810

1908

2056

2144

2232

2343

2455

2737

3100

3622

125

1874

1957

2044

2140

2193

2246

2343

2455

2737

3100

3622

1.5% 1.0% 0.5% 0.25% (1 in 67) (1 in 100) (1 in 200) (1 in 400)

Level

0.25% 0.5% 1.0% 1.5% (1 in 400) (1 in 200) (1 in 100) (1 in 67)

2.0% (1 in 50)

For gradients greater than 1 in 50 rising – use distances for 1 in 50 rising. For gradients greater than 1 in 50 falling – seek derogation. GN Table 1 GN185

RSSB

Composite table for all trains (yards)

GN Table 1 presents the corresponding signalling braking distances for all trains in yards and GN Figure 8 presents the graphical representation of these data.

Page 53 of 103 GK/GN0675 Issue Four September 2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage

GN Figure 8

Composite curves for all trains (yards)

Page 54 of 103 GK/GN0675 Issue Four September 2015

RSSB

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage Appendix B Signalling Braking Distances for Passenger Trains The content of this appendix is mandatory

B.1

Composite table for passenger trains (metres) DISTANCE (METRES) GRADIENT (mm/m) Rising

INITIAL SPEED (mph)

Falling

30 25 20 15 10 5 2.5 (1 in 33) (1 in 40) (1 in 50) (1 in 67) (1 in 100) (1 in 200) (1 in 400)

Level 2.5 5 10 15 20 25 30 Level (1 in 400) (1 in 200) (1 in 100) (1 in 67) (1 in 50) (1 in 40) (1in 33)

10

27

28

29

30

31

32

32

33

33

34

36

38

15

42

44

45

47

49

51

52

53

54

56

59

63

67

72

78

20

62

65

67

70

73

76

78

80

82

84

89

95

101

109

118

25

86

89

93

97

101

106

109

112

115

118

127

136

147

159

174

30

114

120

125

132

138

146

150

154

159

164

175

187

201

218

239

35

150

157

165

173

182

192

197

203

209

215

230

246

265

287

314

40

198

207

215

225

235

246

252

258

266

274

292

312

336

364

399

45

251

263

274

287

300

315

323

332

342

353

377

404

437

476

525

50

313

327

342

359

377

396

407

418

433

447

479

516

561

615

686

55

381

399

418

439

461

487

500

515

533

551

593

642

702

774

871

60

460

483

506

533

562

595

614

632

660

679

734

799

879

979

1117

65

537

564

592

624

658

698

720

742

770

798

864

942

1040

1162

1333

70

624

656

689

728

769

816

843

870

904

938

1018

1113

1234

1387

1607

75

727

766

807

853

904

963

995

1030

1075

1115

1216

1338

1496

1700

2007

80

832

877

925

980

1040

1110

1150

1190

1245

1291

1413

1561

1755

2013

2412

85

940

992

1047

1110

1180

1261

1310

1354

1410

1471

1614

1788

2021

2334

2834

90

1058

1118

1181

1254

1334

1428

1485

1537

1605

1674

1842

2049

2330

2715

3361

95

1190

1260

1333

1418

1511

1621

1680

1750

1835

1913

2113

2366

2713

3207

4100

100

1357

1440

1528

1630

1745

1880

1960

2041

2143

2245

2503

2835

3312

4044

5668

105

1357

1440

1528

1630

1745

1880

1960

2041

2143

2245

2503

2835

3312

4044

5668

110

1357

1440

1528

1630

1745

1880

1960

2041

2143

2245

2503

2835

3312

4044

5668

115

1357

1440

1528

1630

1745

1880

1960

2041

2143

2245

2503

2835

3312

4044

5668

120

1461

1522

1585

1655

1745

1880

1960

2041

2143

2245

2503

2835

3312

4044

5668

125

1579

1646

1714

1789

1869

1957

2000

2054

2143

2245

2503

2835

3312

4044

5668

RSSB

40

43

Page 55 of 103 GK/GN0675 Issue Four September 2015

46

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage

2900

2800

2800

2700

2700

2600

2600

2500

2500

95 M

i le /h

2900

2400

2400 2300

2200

2200 90 M

ile

/h

2300

2100

2000

1900

1900

Mi le/ h

2000

12

le/

h

1800 1700

Mi

le/

h

1700

i 5M

85

1800

h

1400 1300

1200

1200

70

M il e /h

1300

1100 1000

65

1100 h le/ Mi

900 Mi 60

800 700

1000 900

h le/

800 700

ile/h 55 M

600

600 ile/h 50 M

500

ile/h 45 M

400

300

/h 40 Mile

300

35 Mile

200 100 0

2.5% 1 in 40

2.0% 1 in 50

1.5% 1 in 67

1.0% 1 in 100

Rising

GN Figure 9 GN186

500

400

3.0% 1 in 33

(METRES)

80

1500

75

1400

0, 10

1600

ile /

1500

/h /h ile i le 0M 5M 12 1 ,1 0 11 5, 10

M

1600

(METRES)

Minimum Signal Spacing Distance

2100

0.5% 1 in 200

Level

0.5% 1 in 200

GRADIENT

1.0% 1 in 100

/h

/h 30 Mile 25 Mile/h 20 Mile/h 15 Mile/h

200

10 Mile/h

0

1.5% 1 in 67

2.0% 1 in 50

100

2.5% 1 in 40

3.0% 1 in 33

Falling

Composite curves for passenger trains (metres)

GN Figure 9 presents the graphical representation of the data of composite signalling braking distances for passenger trains in metres.

Page 56 of 103 GK/GN0675 Issue Four September 2015

RSSB

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage DISTANCE (YARDS) GRADIENT Rising

Falling

INITIAL SPEED (mph)

1 in 33 3.0%

1 in 40 2.5%

1 in 50 2.0%

10

30

31

32

33

34

15

46

48

49

51

20

68

71

73

77

25

94

97

102

30

125

131

35

164

172

40

217

45

275

50 55 60

1 in 400 0.25%

Level Level

1 in 400 0.25%

1 in 200 0.5%

1 in100 1.0%

35

36

36

37

37

39

54

56

57

58

60

61

65

69

73

79

85

80

83

86

88

90

92

97

104

110

119

129

106

110

116

120

123

126

129

139

149

161

174

190

137

144

151

160

164

168

174

179

191

205

220

238

261

181

189

199

210

216

222

228

235

252

269

290

314

344

226

235

246

257

269

276

283

291

300

319

341

367

398

436

287

300

314

328

345

354

363

374

385

412

442

478

520

574

342

358

374

392

412

434

446

458

473

488

524

564

614

673

750

416

436

457

480

504

532

548

563

583

603

649

702

767

846

953

503

528

554

583

615

651

671

692

717

743

803

873

962

1071

1222

65

587

616

648

682

720

763

787

812

842

873

945

1030 1137 1270

1458

70

682

717

754

796

841

892

921

951

988

1026

1113

1217 1350 1517

1758

75

795

838

882

933

989

1053

1089

1126

1172

1219

1330

1463 1636 1860

2195

80

910

959

1012

1072 1137

1214

1257

1301

1356

1412

1545

1707 1920 2201

2637

85

1028 1085

1145

1214 1290

1379

1430

1481

1545

1609

1765

1956 2210 2552

3099

90

1157 1222

1292

1371 1459

1561

1621

1681

1756

1831

2014

2241 2548 2969

3676

95

1302 1378

1458

1550 1652

1772

1843

1914

2003

2092

2311

2587 2967 3508

4484

100

1484 1575

1671

1783 1908

2056

2144

2232

2343

2455

2737

3100 3622 4423

6198

105

1484 1575

1671

1783 1908

2056

2144

2232

2343

2455

2737

3100 3622 4423

6198

110

1484 1575

1671

1783 1908

2056

2144

2232

2343

2455

2737

3100 3622 4423

6198

115

1484 1575

1671

1783 1908

2056

2144

2232

2343

2455

2737

3100 3622 4423

6198

120

1597 1665

1734

1810 1908

2056

2144

2232

2343

2455

2737

3100 3622 4423

6198

125

1727 1800

1874

1957 2044

2140

2193

2246

2343

2455

2737

3100 3622 4423

6198

GN Table 2 GN187

1 in 67 1 in 100 1 in 200 1.5% 1.0% 0.5%

1 in 67 1 in 50 1 in 40 1 in 33 1.5% 2.0% 2.5% 3.0%

42

44

47

Composite table for passenger trains (yards)

GN Table 2 presents the corresponding signalling braking distances for passenger trains in yards and GN Figure 10 presents the graphical representation of these data.

RSSB

Page 57 of 103 GK/GN0675 Issue Four September 2015

50

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage 3100

3100

3000

3000

2900

2900 2800

2700

2700

95

Mi le/

h

2800

2600

2600 2500

2400

2400

ile /h

2500

2300

90 M

2300

2200

2100

2100

Mi le

/h

2200

2000

1800

M

1700

1500

75

1500

1400

1300

1300

70

M

ile /h

1400

1200 1100

65

1000 900

60

1200

Mi

1100

h le/

1000

le/ Mi

h

900 800

800

55 M

700 600

50 M

500

45 M

400

700 600

ile/h

500

ile/h

400

40 Mile/

300

h

300

35 Mile/h 30 Mile/h

200

200

25 Mile/h 20 Mile/h 15 Mile/h 10 Mile/h

100 0

3.0% 1 in 33

ile/h

2.5% 1 in 40

2.0% 1 in 50

1.5% 1 in 67

Rising

1.0% 1 in 100

0.5% 1 in 200

Level

0.5% 1 in 200

GRADIENT

1.0% 1 in 100

1.5% 1 in 67

2.0% 1 in 50

100 0

2.5% 1 in 40

3.0% 1 in 33

Falling

GN Figure 10 Composite curves for passenger trains (yards)

Page 58 of 103 GK/GN0675 Issue Four September 2015

RSSB

(YARDS)

1600

/h

1600

h le/ h Mi ile/ 15 M 1 0 , 12 10 ,1 05 ,1 0 10

80

1700

1900

h ile/

M ile

1800

5M 12

ile /h

1900

(YARDS)

Minimum Signal Spacing Distance

85

2000

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage Appendix C Signalling Braking Distances for Trains with Enhanced Braking (9%g mean) The content of this appendix is mandatory

C.1 Table for trains with enhanced braking (9%g mean) in metres DISTANCE (METRES) GRADIENT (mm/m) Rising INITIAL SPEED (mph)

Falling

30 25 20 15 10 5 2.5 (1 in 33) (1 in 40) (1 in 50) (1 in 67) (1 in 100) (1 in 200) (1 in 400)

Level Level

2.5 5 10 15 20 25 30 (1 in 400) (1 in 200) (1 in 100) (1 in 67) (1 in 50) (1 in 40) (1 in 33)

10

23

24

25

25

26

27

27

28

29

30

31

33

34

15

37

38

40

41

43

45

46

47

48

49

52

55

59

64

70

20

55

57

60

62

65

68

72

72

74

76

81

86

92

100

110

25

78

81

85

89

93

98

100

103

106

109

117

126

136

149

164

30

105

110

115

121

128

135

139

143

148

153

164

176

191

208

230

35

139

146

153

162

170

180

185

191

197

204

218

235

254

277

306

40

188

196

205

214

224

234

240

246

254

262

279

298

321

347

380

45

232

243

253

264

276

289

296

304

313

322

343

366

393

425

464

50

282

294

306

320

334

351

359

368

379

390

415

442

475

511

557

55

336

350

365

381

399

418

428

438

451

464

493

525

563

606

660

60

395

411

429

448

468

490

502

514

529

544

578

615

659

709

770

65

458

478

497

519

543

568

582

597

614

631

670

712

762

819

890

70

526

548

571

596

623

652

668

684

703

723

767

816

873

937

1017

75

598

624

650

678

708

742

762

779

801

823

872

927

991

1064

1153

80

676

704

734

766

800

838

860

879

904

929

984

1046

1118

1199

1299

85

758

790

823

859

897

940

963

986

1014

1042

1103

1172

1252

1343

1455

90

846

882

919

959

1002

1049

1075

1101

1132

1163

1232

1309

1398

1499

1623

95

939

979

1020

1065

1112

1165

1193

1223

1257

1291

1368

1453

1552

1664

1802

100

1031

1075

1119

1168

1220

1278

1309

1341

1377

1415

1498

1590

1698

1819

1968

105

1132

1179

1228

1282

1339

1402

1437

1472

1514

1553

1644

1745

1862

1994

2157

110

1237

1289

1342

1401

1463

1532

1570

1608

1653

1697

1796

1905

2033

2177

2354

115

1346

1403

1461

1525

1593

1668

1709

1751

1799

1847

1955

2074

2212

2369

2561

120

1461

1522

1585

1655

1728

1810

1855

1900

1952

2004

2121

2250

2400

2569

2777

125

1579

1646

1714

1789

1869

1957

2005

2054

2111

2167

2293

2432

2594

2777

3001

RSSB

37

Page 59 of 103 GK/GN0675 Issue Four September 2015

40

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage 2900

2800

2800

2700

2700

2600

2600

M il e

/h

2900

2500

12 5

2500 2400

M

ile

/h

2400 2300

12 0

2300

2200

M i le

/h

2200

11 5

2100

/h

2100 2000

11 0

M

ile

2000

M il e /h

1900

1700

10 0

M ile

/h

1700

1500

9

1600

/h i le 5M

1400

M 90

1300 1200 1100

900

1300

/h

1200 1100

h le / Mi

80 75

1400

h ile/

le Mi

85

1500

1000

h le / Mi

900

h le / Mi

800

70

700

il 65 M

800

e/h 700

ile/h 60 M

600

il 55 M

500

il 50 M 400

600

e/h 500

e/h

e/h

400

300

/h 40 Mile

300

200

35 Mile/h 30 Mile/h

200

il 45 M

25 Mile/h 20 Mile/h 15 Mile/h 10 Mile/h

100 0

3.0% 1 in 33

2.5% 1 in 40

2.0% 1 in 50

1.5% 1 in 67

Rising

GN Figure 11

1.0% 1 in 100

0.5% 1 in 200

Level

0.5% 1 in 200

GRADIENT

1.0% 1 in 100

1.5% 1 in 67

2.0% 1 in 50

100 0

2.5% 1 in 40

3.0% 1 in 33

Falling

Curves for trains with enhanced braking (9%g mean) in metres

GN Figure 11 presents the graphical representation of the data for trains with enhanced braking (9%g mean) in metres.

Page 60 of 103 GK/GN0675 Issue Four September 2015

RSSB

(METRES)

1600

1000

GN188

1800

10 5

1800

(METRES)

Minimum Signal Spacing Distance

1900

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage DISTANCE (YARDS) GRADIENT Rising INITIAL SPEED (mph)

Falling

1 in 33 1 in 40 1 in 50 1 in 67 1 in 100 1 in 200 1 in 400 Level 3.0% 2.5% 2.0% 1.5% 1.0% 0.5% 0.25% Level

1 in 400 1 in 200 1 in 100 1 in 67 1 in 50 1 in 40 1 in 33 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 0.25%

10

25

26

27

27

28

30

31

31

32

33

34

36

37

40

44

15

40

42

44

45

47

49

50

51

53

54

57

60

65

70

77

20

60

62

66

68

71

74

77

79

81

83

89

94

101

109

120

25

85

89

93

97

102

107

110

113

116

119

128

138

149

163

179

30

115

120

126

132

140

148

152

156

162

167

179

193

209

228

252

35

152

160

167

177

186

197

203

209

216

223

238

257

278

303

335

40

206

215

224

234

245

256

263

269

277

286

305

326

351

380

415

45

254

265

276

289

302

317

325

333

343

353

375

400

430

464

507

50

308

321

335

350

366

383

393

403

415

426

453

484

519

559

609

55

367

383

399

417

436

457

468

479

494

508

539

575

616

663

722

60

432

450

469

489

511

536

550

563

579

595

632

673

721

775

842

65

501

522

544

568

593

622

638

653

671

690

732

779

834

896

973

70

575

599

624

652

681

713

731

748

770

791

839

892

954

1025 1112

75

654

682

710

742

775

811

831

851

876

900

954

1014 1084 1163 1261

80

739

770

802

837

875

916

939

962

989

1016 1076 1144 1222 1311 1421

85

829

864

900

939

981

1028 1053 1079

1109

1139 1207 1282 1370 1469 1591

90

925

965

1005 1049 1096 1148 1176 1205

1238

1272 1347 1431 1529 1639 1775

95

1027 1071 1115 1164 1216 1274 1305 1337

1375

1412 1496 1589 1697 1820 1970

100

1128 1175 1224 1278 1334 1397 1432 1467

1507

1548 1639 1739 1857 1989 2152

105

1238 1290 1343 1402 1464 1533 1571 1609

1654

1698 1798 1908 2036 2181 2359

110

1352 1409 1468 1532 1600 1675 1717 1759

1807

1855 1964 2084 2223 2381 2574

115

1472 1534 1598 1668 1742 1824 1869 1914

1967

2020 2137 2268 2420 2590 2800

120

1597 1665 1734 1810 1890 1979 2028 2078

2135

2192 2319 2460 2625 2810 3037

125

1727 1800 1874 1957 2044 2140 2193 2246

2308

2370 2507 2659 2837 3037 3282

GN Table 3 GN189

RSSB

Table for trains with enhanced braking (9%g mean) in yards

GN Table 3 presents the corresponding signalling braking distances for passenger for trains with enhanced braking (9%g mean) in yards and GN Figure 12 presents the graphical representation of these data.

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Guidance on Lineside Signal Spacing and Speed Signage 3100

3000

3000

2900

2900

2800

2800

M ile

/h

3100

2700

12 5

2700

2600

M ile

/h

2600

2500

12 0

2500

2400

M

ile

/h

2400

11 0 10 5

1900

M ile /h

1900

1800

10 0

1800 1700

9

1600

(YARDS)

2000

M ile /h

2000

2100

1700

h ile/ 5M

1600

h

1500

le/ Mi

1500

90 1400

1400

Mi 85

1300 1200

80

le Mi

1100

M 75

1000

le/

h 1300

/h

1200 1100

/h i le

1000

h le/ Mi

900

70

800

ile/h 65 M

800

700

ile/h 60 M

700

600

ile/h 55 M

600

500

ile/h 50 M

500

400

ile/h 45 M

400

900

e/h 40 Mil

300

300

/h 35 Mile /h ile 30 M

200

200

25 Mile/h 20 Mile/h 15 Mile/h 10 Mile/h

100 0

3.0% 1 in 33

2.5% 1 in 40

2.0% 1 in 50

1.5% 1 in 67

Rising

1.0% 1 in 100

0.5% 1 in 200

Level

0.5% 1 in 200

GRADIENT

1.0% 1 in 100

1.5% 1 in 67

2.0% 1 in 50

100 0

2.5% 1 in 40

3.0% 1 in 33

Falling

Curves for trains with enhanced braking (9%g mean) in yards

Page 62 of 103 GK/GN0675 Issue Four September 2015

RSSB

(YARDS)

2100

Minimum Signal Spacing Distance

2200

M ile /h

2200

GN Figure 12

2300

11 5

2300

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage Appendix D Temporary Speed Restrictions The content of this appendix is mandatory

D.1

Position of speed indicators and termination indicators

D.1.1

General requirements D.1.1.1 Where temporary speed restriction speed indicators are required (see 3.4.1.1), they shall be positioned:

D.1.1.2

a)

On the approach to the temporary speed restriction, and

b)

As close as practicable to the location where the temporary speed limit commences.

Additional speed indicator(s) shall be provided within a temporary speed restriction in the following circumstances: a)

At a position where trains are permitted to reverse direction (for example, at the signal at which the train may reverse direction). In this case the WON shall specify: ‘The speed indicator on the ___ line at ___ miles ___ chains is provided for trains turning back at this location.’

b)

Where there is an operational requirement to change drivers (for example, at stations). In this case the WON shall specify: ‘The speed indicator on the ___ line at ___ miles ___ chains applies to changing crews at this location.’

GN190

Drivers should normally observe only one speed indicator for each temporary speed restriction, positioned at the location where the speed restriction commences.

GN191

Where a train may stop part way through a temporary speed restriction, an additional indicator should be provided to display the applicable temporary speed restriction to the driver before the train is restarted, if either a different driver may take over or the train may reverse direction.

GN191a

The rationale for the provision of additional speed indicators is to remind the driver that the train is subject to a TSR.

GN191b

Clause D.1.1.2a) applies only to locations where trains are booked to reverse direction; it does not apply to shunting movements. Clause D.1.1.2b) applies only to locations where trains are booked to change drivers. This information should be obtained locally.

GN192

RSSB

D.1.1.3

Where differential speeds apply, all the required speed indicators and directional indicators shall be positioned together.

D.1.1.4

It is permitted for nominally co-located signs to be separated by a short distance where this would not impair readability.

Where differential speeds apply to a temporary speed restriction, the two applicable speeds are shown on the same sign at the warning indicator and at the commencement indicator. Where a directional arrow is required, this also should be on the same sign as the speed indicators, in order to convey the correct meaning to the driver.

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Guidance on Lineside Signal Spacing and Speed Signage GN193

Where space is restricted (for example, where a sign has to be mounted between adjacent tracks), there may be insufficient room for a speed indicator or warning indicator with differential speeds and a directional arrow. If it is not practicable to provide appropriate signage to allow the application of differential speeds, it may be necessary to impose a single speed limit (the lowest applicable speed) for all trains.

D.1.2

Position of speed indicators at converging junctions D.1.2.1 Where lines converge within a temporary speed restriction, a speed indicator shall be provided at each entry to the speed restriction before the convergence, so that trains pass only one speed indicator applicable to the restriction (see Figure D-1).

20

Additional indicator 20 for converging line

50

90

20

T

20 20

90

Figure D-1 Example of speed indicators at converging junction (D.1.2.1) GN194

The principle that a driver should normally observe only one speed indicator for each temporary speed restriction is the same as that applied for permissible speed warning indicators as set out in 3.3.6.1.

GN195

By exception, where the temporary speed restriction applicable through the converging junction is higher than the permissible speed for the converging line at the junction points, the speed indicator for trains from the converging line should be positioned beyond the junction points to avoid conflicting speed indications approaching the junction. In this case drivers on the higher speed route pass a second speed indicator within the speed restriction.

D.1.3

Position of speed and termination indicators at diverging junctions D.1.3.1 A speed indicator, with an arrow indicating the direction of divergence, shall be provided on the approach to any diverging junction or facing crossover on or over which there is a temporary speed restriction.

GN196

The speed indicator should be provided close to the diverging turnout so that it is obvious that it applies to the turnout, but it may be necessary to position it clear of existing signs (for example, permanent permissible speed indicators) adjacent to the turnout. D.1.3.2

Where a temporary speed restriction only applies to the trailing point end of a crossover and the speed indicator cannot be placed at a position within the crossover, the speed indicator (with directional arrow) shall be placed before the facing point end (see Figure D-2). In this case the WON shall specify: ‘The speed indicator on ___ line at ___ miles ___ chains applies only to trains using the crossover to ___ line.’

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Guidance on Lineside Signal Spacing and Speed Signage Directional indication required 20

90

T

90 20

50

110

50

20 20

20

90

Commencement of 20 speed restriction 110

Figure D-2 Example of TSR over trailing end of crossover (D.1.3.2) GN197

In the example shown in Figure D-2, the speed indicator for the 20 mph temporary speed restriction is placed before the facing points of the crossover (adjacent to the existing permissible speed indicator), even though the temporary speed restriction has been applied only to the line through the trailing end of the crossover.

GN198

Drivers observing the speed indicator and arrow should understand that the speed restriction only applies to the crossover move. D.1.3.3

Where a temporary speed restriction applies only over the facing point end of a crossover, a termination indicator (or, if entering another adjoining temporary speed restriction, a speed indicator displaying the value of that speed restriction) shall be placed adjacent to the trailing point end (see Figure D-3). In this case the WON shall specify: ‘The termination indicator on ___ line at ___ miles ___ chains applies only to trains using the crossover from ___ line.’

T 90 90

90 20

20

50 20 20

Termination of 20 speed restriction

T

110

50

110

Figure D-3 Example of TSR over facing end of crossover (D.1.3.3) GN199

In the example shown in Figure D-3, the termination indicator for the 20 mph temporary speed restriction (which applies only to the line through the facing end of the crossover) cannot be placed part way through the crossover, and is placed adjacent to the trailing end. Trains on the straight line through the trailing end of the crossover, therefore, pass this termination indicator, although it does not apply to them; the WON entry explains the situation.

D.2

Temporary speed restriction warning boards and AWS equipment

D.2.1

General requirements for warning boards D.2.1.1 Warning board(s) shall be positioned as close as practicable to (but not less than) the deceleration distance from the associated speed indicator. D.2.1.2

RSSB

Where the temporary speed restriction commences at an increase of permissible speed, and the speed of the TSR is the same as, or higher than, the speed on the approach, the warning board(s) shall be positioned at a minimum distance from the associated speed indicator equivalent to a running time of four seconds at the permissible speed.

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Guidance on Lineside Signal Spacing and Speed Signage GN200

The temporary speed restriction warning board should provide sufficient deceleration distance for all types of trains. Where differential permissible speeds apply on the approach to the temporary speed restriction, the longest deceleration distance required should be allowed for.

GN201

The longest deceleration distance required may be significantly longer than the distance required by some trains. Such excess spacing is undesirable, but unavoidable, given that Appendix X needs to accommodate the worst braked trains.

GN202

The distance between the warning board and the speed indicator should not be significantly greater than the longest deceleration distance required, because this may make it difficult for train drivers to judge where they need to begin braking. This could lead to early or late brake application by drivers. Therefore, the warning board should be positioned as close as possible to the position that provides the longest deceleration distance from the speed indicator.

GN202a

Four seconds provides the driver with enough time to comply with the TSR before the train reaches the speed indicator, including time to: a)

Interpret that the train is approaching the TSR.

b)

Decide what action, if any, is needed to comply with the TSR. In this case, the required action may be a change to the usual operation of increasing the speed of the train at that location.

c)

Take the necessary action, if any.

D.2.1.3

GN203

The distance from the warning board to the speed indicator shall be extended: a)

Where this is necessary to avoid AWS conflicts (see D.2.4).

b)

So that a warning board is not positioned between existing AWS equipment and the equipment to which the AWS applies.

The distance between the temporary speed restriction warning board and the speed indicator may need to be increased to provide adequate sighting, or to avoid AWS conflicts or positions where it is not practicable to provide the warning board. D.2.1.4

Where the required deceleration distance from the permissible speed on the immediate approach to the temporary speed restriction would result in the warning board being positioned in a section of line with a higher permissible speed, the deceleration distance shall be determined using that higher permissible speed (see Figure D-4).

DD 40 – 20 60

20 60

40

20

60

20 40

20

DD 60 – 20

Figure D-4 Example of TSR with a higher permissible speed on approach (D.2.1.4)

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Guidance on Lineside Signal Spacing and Speed Signage D.2.1.5

Where the required deceleration distance from the permissible speed on the immediate approach to the temporary speed restriction would result in the warning board being positioned in a section of line with a lower permissible speed, the deceleration distance required for this lower permissible speed shall be determined. If the revised position of the warning board still falls within that lower permissible speed section, it shall be positioned at that distance (see Figure D-5). DD 40 – 20

DD 60 – 20 40

20

20

40

60 40

20 60

20

Figure D-5 Example of TSR with a lower permissible speed on approach (D2.1.5) D.2.1.6

If the revised position of the warning board as set out in D2.1.5 lies between the permissible speed indicator at the commencement of the higher permissible speed section and the temporary speed restriction speed indicator, the warning board shall be positioned at the permissible speed indicator for the higher speed section to prevent acceleration (see Figure D-6).

(> DD 30 – 20) 20 30

20 30

20

60 30

DD 60 – 20

60

20 60

20

DD 30 – 20

Figure D-6 Example of TSR with warning board at commencement of higher permissible speed (D.2.1.6)

GN204

RSSB

In the examples shown in Figures D-4, D-5 and D-6, the initial calculation of warning board position for the 20 mph temporary speed restriction would result in either insufficient braking distance (Figure D-4), excess braking distance (Figure D-5) or in a confusing arrangement (Figure D-6). This is due to the variations in permissible speed on the approach to the temporary speed restriction. The aim of sensible positioning of the warning board is to avoid driver confusion and to enable them to drive their trains in the optimum manner.

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Guidance on Lineside Signal Spacing and Speed Signage D.2.2

Requirements for warning boards at converging junctions D.2.2.1 Where the deceleration distance requires a warning to be given on the approach to a converging junction, a warning board shall be positioned at the appropriate deceleration distance on each line approaching the speed indicator (see Figure D-7). DD 50 – 20 # 50

20 50

20

20

90

20 # DD 90 – 20

Figure D-7 Example of warning board positioning at a converging junction (D.2.2.1) D.2.2.2

GN205

D.2.3

Where the required deceleration distances would position one of the warning boards on the approach to a convergence, then all warning boards shall be positioned before the convergence so that a train passes only one warning board on any approach to the temporary speed restriction.

It is undesirable for a driver to pass more than one warning board for the same temporary speed restriction. Therefore, if the deceleration distance required for the higher speed approach places the warning board before a converging junction, the warning for a lower speed approach should also be placed before the converging junction.

Requirements for warning boards at diverging junctions D.2.3.1 Where a temporary speed restriction applies over or beyond a diverging junction, and the required deceleration distance places the warning board before the junction (see Figure D-8), the warning board shall incorporate an arrow indicating the direction of divergence. In this case the WON shall specify: ‘The warning board situated on the ___ line at ___ miles ___ chains applies to trains proceeding to the ___ line.’

< DD 60 – 20

20 20

20 110

60

60 110

Figure D-8 Example of warning board positioning at a diverging junction (D.2.3.1)

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Guidance on Lineside Signal Spacing and Speed Signage D.2.3.2

Where the deceleration distance would provide a warning board on a diverging line at a position that would cause the associated AWS permanent magnet to be located at or before the facing points, all of the following arrangements shall apply (see Figure D-9): a)

The warning board shall incorporate a directional arrow.

b)

The warning board shall be positioned at the facing points.

c)

The AWS magnet shall be positioned at the required distance on the approach to the warning board.

Figure D-9 Example of a diverging junction with warning board located at the facing points (D.2.3.2)

GN206

In certain cases the deceleration distance for a temporary speed restriction would place the warning board a short distance beyond the facing points of a diverging junction, and the associated AWS magnet would require to be positioned before the facing points. That arrangement would be unacceptable, since a train on the straight route would receive a warning on passing over the AWS magnet, but would not pass the warning board.

GN207

In such cases the arrangement shown in Figure D-9 should be adopted. The warning board is placed at the facing points, and in most cases is adjacent to the permissible speed indicator for the diverging route. All trains should pass over the AWS magnet and should also pass the warning board, which has a directional arrow to identify that it applies to the diverging route only.

RSSB

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Guidance on Lineside Signal Spacing and Speed Signage D.2.3.3

Where the deceleration distance would provide the warning board on the approach to a junction signal that is approach controlled from red (permanent or temporary approach control) all of the following arrangements shall apply: a)

The deceleration distance shall be determined using the junction speed.

b)

The warning board shall be positioned at or after the sighting point of the signal (including the route indicator), or of the splitting banner repeating signal, where provided (see Figure D-10).

c)

The WON shall specify: ‘The warning board situated on the ___ line at ___ miles ___ chains applies to trains proceeding to the ___ line.’

20 90

90

DD Junction Speed – 20 20

20

40

110

110 # Warning board positioned after the sighting point of signal & route indicator (or splitting banner where provided)

Figure D-10

Example of a diverging junction where signal is approach released from red (D.2.3.3)

GN208

The arrangement in Figure D-10 relies on the fact that, when a train is to be routed to the diverging route, the aspect sequence causes the approach speed of the train to be reduced. The driver should be prepared to stop at the junction signal until the proceed aspect (or the splitting banner repeating signal, where provided) is observed for the diverging route.

GN209

Because the warning board is positioned after the sighting point of the signal, the driver knows that if the signal displays a proceed aspect for the diverging route, it is necessary to control the speed of the train for the permissible speed restriction on the diverging route, and for the temporary speed restriction beyond the junction.

GN210

It is permissible for the AWS magnet for the warning board to be positioned before the sighting point of the signal.

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Guidance on Lineside Signal Spacing and Speed Signage D.2.3.4

Where the deceleration distance would provide the warning board on the approach to a junction signal and the signalling aspect sequence provides information to the driver on which route has been set (for example, the junction signal is approach controlled from yellow with flashing yellows or splitting distant in rear), all of the following arrangements shall apply: a)

The warning board shall be positioned at the deceleration distance calculated using the permissible speed of the line (see Figure D-11).

b)

The WON shall specify: ‘The warning board situated on the ___ line at ___ miles ___ chains applies to trains proceeding to the ___ line.’

20 90

90 20

20

70 110

110

# DD 110 – 20 Figure D-11 Example of a diverging junction where signal is approach released from a higher aspect (D.2.3.4) GN211

A junction signalling aspect sequence using flashing yellow aspects or splitting distant signals provides the driver with advance information about the route that is set, and so allows a train to approach a diverging junction at a higher speed than approach control from red would permit. It is therefore necessary to provide a warning board for a temporary speed restriction on the diverging route at an earlier position than shown in Figure D-10. The driver should be aware that the train is routed towards the temporary speed restriction and should be able to control the speed of the train accordingly. D.2.3.5

RSSB

Where the deceleration distance would provide the warning board on the approach to a junction signal that is not approach controlled or that displays a free single yellow with a standard 4-aspect sequence on the approach, all of the following arrangements shall apply: a)

Temporary approach control from red shall be applied to the signal for the applicable diverging route or straight route (see Figure D-12, which sets out an example of a temporary speed restriction on the straight route).

b)

The signal aspect release point shall be at or after the sighting point of the signal (including the route indicator, where applicable), or of the splitting banner repeating signal, where provided.

c)

The warning board shall be positioned so that it is visible to the driver when the signal aspect is released from red to display a proceed aspect.

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Guidance on Lineside Signal Spacing and Speed Signage 60 20

Temporary approach control of appropriate route 60 20 40 60

60

20

# Warning board positioned after the sighting point of signal & route indicator (or splitting banner where provided)

Figure D-12

Example of a diverging junction where no previous routing advice is given (D.2.3.5)

GN212

A junction signalling aspect sequence without approach control, or using free yellow with a standard 4-aspect sequence on the approach, allows a train to approach a diverging junction at a higher speed than approach release from red. It does not provide the driver with advance information about which route the train is to take.

GN213

The driver does not know which way the train is to be routed before the junction signal aspect (or splitting banner repeating signal, where provided) becomes visible. It would, therefore, be unacceptable to provide the warning board at full deceleration distance (as shown in Figure D-11) because the driver would not yet know whether the temporary speed restriction applied to that train movement.

GN214

It is therefore necessary to apply temporary approach control from red (where provided) to the junction signal for the route towards the temporary speed restriction (which may be the straight route or a diverging route), and apply a similar arrangement to that shown in Figure D-11. Where temporary approach control facilities are not provided, either:

D.2.4

a)

The speed indicator should be repositioned on the approach to the diverging junction, so that the temporary speed restriction applies to all routes through the junction, or

b)

A separate temporary speed restriction should be imposed before the diverging junction, of low enough value to allow positioning of the warning board for the required temporary speed restriction on the approach to the AWS magnet for the junction protecting signal.

Requirements for AWS permanent magnets and AWS cancelling indicators D.2.4.1 Except where D.2.4.2 applies, an AWS permanent magnet shall be positioned: a)

On all lines that signalled running moves approach the warning board, whether or not the line is fitted with AWS (see Figure D-13).

b)

180 m (200 yd) on the approach to the temporary speed restriction warning board, unless the criteria in D.2.4.3 apply.

c)

Where the criteria in D.2.4.3 apply, between 45 m (50 yd) and 180 m (200 yd) from the warning board, subject to a minimum of 4 seconds running time at permitted speed (see Figure D-14).

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Guidance on Lineside Signal Spacing and Speed Signage 50

DD 90 – 20

# 20

90

90 #

Figure D-13 Example of usual positioning of AWS magnets (D.2.4.1a)

(> DD 90 – 20)

20

#

DD 90 – 20 20

90 4 seconds (min 45 m [50 yd])

<#

Portable AWS not allowed within these limits Figure D-14 Example of critical positioning of AWS magnets (D.2.4.1c)

GN215

AWS magnet(s) should always be provided for each temporary speed restriction warning board, including where the line concerned is not fitted with AWS. This is so that the driver is specially alerted to the presence of the warning board, because the driver is not familiar with the position of temporary speed restrictions as part of route knowledge. A limited number of exceptions are set out in D.2.4.2.

GN216

The standard position for these AWS magnets is 180 m on the approach to the warning board.

GN217

Where conditions such as those set out in D.2.4.3 prevent the positioning of an AWS magnet 180 m from the warning board, the magnet should be positioned between 45 m and 180 m from the warning board, subject to a minimum of 4 seconds running time at the permissible speed. The minimum 4 seconds requirement is so that the AWS receiver has time to reset and is ready to respond correctly to the next AWS magnet following a caution indication, which could be acknowledged at the end of the acknowledgement delay period.

D.2.4.2

The AWS permanent magnet shall not be provided, either: a)

In an AWS gap area (see GE/RT8075), or

b)

On lines from which trains always start from rest, for example, bay or terminal platforms. In this case the WON shall specify: ‘No AWS at warning board on ___ line at ___ miles ___ chains.’

GN218

AWS magnets for temporary speed restriction warning boards are not provided within designated AWS gap areas, such as some major stations. While this means that drivers do not receive an AWS indication, AWS gap areas are generally associated with complex infrastructure layouts where train movements are diverse and permissible speeds are low.

GN219

AWS magnets are not provided in bay or terminal platform lines where trains always start from rest, because the AWS cannot be configured to provide 4 seconds advance warning for the stationary train in this situation. If an arriving train were to stop with the receiver on

RSSB

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Guidance on Lineside Signal Spacing and Speed Signage what would become the leading cab (upon reversal) directly over the magnet applicable to the starting signal, it would not be possible to correctly set up the leading cab. GN220

Where AWS is not provided, the WON is the means of drawing the driver’s attention to the absence of AWS on the approach to the temporary speed restriction warning board. D.2.4.3

D.2.4.4

The AWS permanent magnet shall not be positioned within 4 seconds running time of the AWS equipment associated with any of the following, which apply in the same direction: a)

A signal (including fixed distant boards and SPAD indicators).

b)

A permissible speed warning indicator.

c)

A level crossing advanced warning sign (St. Georges Cross).

By exception, where no other configuration of warning board and AWS position is practicable: a)

The warning board shall be positioned at a signal.

b)

The AWS equipment associated with the signal shall be re-configured to generate an AWS caution indication in the driving cab, regardless of the aspect displayed by the signal (see Figure D-15). In this case the infrastructure manager shall assess the SPAD risk arising from disconnection of the AWS, and ensure that the correct AWS functionality for the signal is restored at the earliest opportunity.

c)

The WON shall specify: ‘Warning Board positioned at signal no. ___ on ___ line, an AWS warning indication will be given irrespective of the aspect exhibited by the signal.’

20

Disconnect AWS Figure D-15 Example of warning board at signal with signal AWS electromagnet disconnected (D.2.4.4)

GN221

Wherever practicable, a separate AWS magnet should be provided for a temporary speed restriction warning board so that drivers receive an AWS caution specifically for the warning board.

GN222

Where it is not practicable to position the warning board so that a separate AWS magnet can be provided for it, the arrangement shown in Figure D-14 could be used. In this arrangement the warning board is positioned adjacent to a signal and makes use of the existing AWS magnet associated with the signal. The AWS electromagnet should be disconnected so that the AWS always gives a caution indication regardless of the aspect displayed by the signal.

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Guidance on Lineside Signal Spacing and Speed Signage GN223

GN224

This arrangement has the following disadvantages: a)

When the signal is displaying a cautionary aspect, drivers receive a single AWS caution indication for two different functions (that is to say, the signal and the warning board).

b)

When the signal is displaying a green aspect, the driver receives a caution indication at the AWS.

The risks in this situation are that: a)

Drivers associate the AWS warning with a cautionary aspect shown by the signal, and fail to observe the temporary speed restriction warning board, leading to insufficient deceleration for the temporary speed restriction.

b)

Drivers become accustomed to receiving an AWS caution for the temporary speed restriction warning board when the signal is green, and are not alerted by the AWS to the signal when it is showing a cautionary aspect, potentially leading to a SPAD.

GN225

Because of this possibility, the SPAD risk arising from the disconnection of the AWS should be assessed before this arrangement is implemented, and the period for which it is applied should be kept as short as possible.

GN226

This arrangement should not be applied at any signal where the consequences of a SPAD are high (for example, signals protecting converging or crossing movements, or the entry to bi-directional lines), or at a signal that displays a cautionary aspect on the approach to such a signal.

D.2.4.5

On single or bi-directional lines, where it is possible to utilise existing AWS equipment associated with a signal or sign for the opposing direction, which is normally suppressed for movements in the direction towards the warning board (see Figure D-16): a)

The warning board shall be positioned to utilise the existing AWS equipment for the opposing direction.

b)

The warning board shall be positioned at the required distance beyond the existing AWS equipment (see D.2.4.1).

c)

The suppression shall be disconnected.

d)

An AWS cancelling indicator shall not be provided.

Disconnect suppression

#

20 90

90 DD 90 – 20

Figure D-16 Example of disconnection of suppressor on existing magnet (D.2.4.5) GN227

On lines signalled for movements in the opposite direction to that required for the temporary speed restriction, the preferred arrangement is to use an existing magnet. Some latitude in the positioning of the warning board is permitted to enable this arrangement to be utilised.

GN228

Where the magnet is suppressed for movements in the direction of the temporary speed restriction, it is necessary to disconnect the suppressor so that a warning is given to trains approaching the warning board.

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Guidance on Lineside Signal Spacing and Speed Signage D.2.4.6

D.2.4.7

On single and bi-directional lines, except where the arrangement in D.2.4.5 is used, an AWS cancelling indicator shall: a)

Be provided.

b)

Be positioned 180 m (200 yd) beyond the portable AWS equipment when travelling in the direction for which the warning is not applicable (see Figures D-17 and D-18). This distance shall be adjusted to avoid conflict with other equipment so that the AWS cancelling indicator is positioned between 4 and 7 seconds running time from the AWS equipment, subject to a minimum of 45 m (50 yd).

On single or bi-directional lines: a)

The AWS permanent magnet and its AWS cancelling indicator shall not be positioned between a signal or a sign (that apply to movements in the same direction as the AWS cancelling indicator), and the AWS equipment associated with that signal or sign.

b)

The warning board shall be positioned accordingly (see Figures D-17 and D-18). # # 20 90

90

Figure D-17 Example showing use of AWS cancelling indicator (D.2.4.6 / D.2.4.7)

#

90

#

20 90

Figure D-18 Another example showing use of AWS cancelling indicator (D.2.4.6 / D.2.4.7)

GN229

Because it is not practicable to provide suppression for a temporary AWS magnet on a single or bi-directional line, the restrictions set out in GE/RT8075, (which normally apply to the use of AWS cancelling indicators) are not applicable, and a cancelling indicator should be provided for movements in the opposite direction (see D.2.4.6 and D.2.4.7).

GN230

Where use of existing AWS equipment is not practicable, the position of the AWS magnet (and therefore the warning board) is dictated by the positioning of the cancelling indicator, which should not conflict with other AWS indications, signals or signs.

GN231

Temporary AWS magnets or cancelling indicators should not be located between a signal or sign that applies to movements in the same direction as the AWS cancelling indicator (that is to say, in the opposite direction to movements to which the temporary speed restriction warning board applies) and the AWS equipment associated with that signal or sign. This is because passing a cancelling indicator after receiving a valid AWS indication could mislead the driver.

Page 76 of 103 GK/GN0675 Issue Four September 2015

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Guidance on Lineside Signal Spacing and Speed Signage GN232

Figure D-17 shows a situation where the required deceleration distance places the warning board at a position which allows the temporary AWS magnet and cancellation indicator to be positioned before the existing AWS magnet associated with the signal. This is an acceptable arrangement.

GN233

The distance between the temporary speed restriction warning board and the temporary AWS magnet, and between the temporary AWS magnet and the cancellation indicator, shown by ‘#’ in Figures D-17 and D-18, should both normally be 180 m, but could be reduced, as set out in D.2.4.

GN234

Where the required deceleration distance would place the warning board too close to the signal to permit the arrangement shown in Figure D-17 to be used, the warning board should be positioned as shown in Figure D-18. This allows the temporary AWS magnet to be located beyond the signal for a move towards the cancellation indicator.

GN235

The warning board should not be positioned between the locations shown in Figures D-17 and D-18. D.2.4.8

Where the deceleration distance means that a warning board is to be positioned on a line not fitted with AWS, between a junction leading onto an AWS fitted line and the protecting signal, the warning board shall be positioned at the signal and provided with its own portable AWS equipment (see Figure D-19). In this case the WON shall specify: ‘Warning Board positioned at signal no. ___ on ___ line applies to trains proceeding towards the ___ line. An AWS warning indication will be given irrespective of the aspect exhibited by the signal.’ DD 110 – 20 20

#

20

110

Fitted

110 20

Unfitted

40

40 #

Figure D-19

20

30 30 Unfitted

> DD 40 – 20

Example showing provision of a warning board on an unfitted line leading to a fitted line (D.2.4.8)

GN236

Where it is necessary to position a warning board on a line not fitted with AWS for a temporary speed restriction that only applies to an adjacent fitted line, and an AWS magnet for movements to the fitted line is provided beyond the signal in accordance with GE/RT8075, the warning board is normally located adjacent to the signal with a separate temporary AWS magnet on the approach.

GN237

The arrangements are similar to those in D.2.3.3. All trains should receive a warning at the AWS magnet, whether or not they are proceeding towards the temporary speed restriction, the applicability of which is indicated by the arrow on the warning board.

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Guidance on Lineside Signal Spacing and Speed Signage D.2.4.9

Where the deceleration distance means that a warning board is required on an AWS fitted line 4 to 7 seconds running time beyond a crossover from an unfitted line, where AWS equipment is provided ahead of the signal for trains proceeding onto the fitted line, all the following arrangements shall apply (see Figure D-20): a)

The existing AWS equipment shall be re-configured so that a caution indication is provided in the driving cab.

b)

A permanent magnet shall not be provided.

c)

The WON shall specify:

‘The AWS magnet for signal no. ___ on ___ line will give an AWS warning indication for trains proceeding towards the warning board on ___ line at ___ miles ___ chains irrespective of the aspect exhibited by the signal.’ #

DD 110 – 20 20

110

Fitted

110 30 30

40

Unfitted

40

Unfitted

# Disconnect electro-magnet

Figure D-20

Example showing disconnection of AWS in advance of protecting signal leading to a fitted line (D.2.4.9)

GN238

In the case where the warning board is located just beyond the junction from the unfitted line to the fitted line, it is permissible to disconnect the electromagnet of the AWS magnet, which is provided beyond the signal for movements to the fitted line in accordance with GE/RT8075, so that this gives a warning for the TSR warning board irrespective of the aspect shown by the signal. In this case the normal arrangements for suppression of this AWS magnet for a train proceeding along the unfitted route continues to apply, so that the warning is only received for trains travelling towards the temporary speed restriction.

GN239

The conditions associated with disconnecting the electromagnet at the AWS equipment associated with a signal, as set out in D.2.4.6, also apply in this case.

D.2.5

Repeater warning boards D.2.5.1 A repeater warning board, showing the restricted speed shall be provided where: a)

The deceleration distance means that the warning board is positioned on the approach to a passenger station, or on a bay platform line or siding, and

b)

The associated speed indicator is positioned at least 300 m beyond the station or siding connection.

D.2.5.2

Each repeater warning board shall be configured as shown in Figure D-21 and positioned so that it is visible to drivers before trains start from rest.

D.2.5.3

Repeater warning boards shall be provided from any other line where trains always start from rest.

D.2.5.4

AWS permanent magnets shall not be provided for repeater warning boards.

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Guidance on Lineside Signal Spacing and Speed Signage D.2.5.5

Where repeater warning boards are provided, the WON shall specify either: ‘Repeater warning board positioned ahead of ___ station, for temporary speed restriction on the ___ line commencing at ___ miles ___ chains.’ or ‘Repeater warning board positioned at signal no. ___, for temporary speed restriction on the ___ line commencing at ___ miles ___ chains.’

20 R

PLATFORM LOOP

20

R

SIDING GOODS LOOP

20 R

90

MAIN LINE

20

20

R

20

90

20

> 300 m Figure D-21 Example showing use of repeater warning boards (D.2.5.2)

GN240

Where trains may start from a station or siding situated between the warning board and the commencement of a temporary speed restriction, repeater warning boards, showing the restricted speed (or the ‘spate’ symbol if the speed restriction has been lifted or not imposed), are provided to remind the driver of a train starting from that location of the temporary speed restriction ahead, while avoiding giving multiple warnings to a through train which has already passed the normal warning board.

GN241

Section 3.4.1.4 states that repeater warning boards are not required on lines where trains always start from rest at a distance of less than 300 m from the commencement of the temporary speed restriction.

GN242

The ‘R’ is placed above the speed numeral to enhance drivability. With repeater boards located just beyond platform ramps, the previous arrangement of speed numeral over ‘R’ resulted in drivers seeing the speed first. This could be mistaken for the commencement of the TSR.

D.3

Requirements for adjacent temporary speed restrictions

D.3.1

Where a lower speed is followed by a higher speed D.3.1.1 Where a temporary speed restriction is immediately followed by another temporary speed restriction with a higher speed all of the following arrangements shall apply (see Figure D-22):

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a)

A speed indicator for the higher temporary speed restriction shall be positioned at the end of the lower speed restriction.

b)

A termination indicator shall not be provided for the lower temporary speed restriction.

c)

A warning board shall not be provided for the higher temporary speed restriction.

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Guidance on Lineside Signal Spacing and Speed Signage d)

The WON shall specify: ‘No warning board for ___ mph speed restriction on ___ line commencing at ___ miles ___ chains.’ DD 90 – 20

20

DD 90 – 50 20

50

90

20

20

50

90 (extended 50)

T

T

90

Commencement of work

50

50

90

Figure D-22 Example of a lower TSR followed by a higher TSR (D.3.1.1)

GN243

Where one temporary speed restriction is followed by another which is a higher speed, there is no requirement for a warning board for the second (higher) speed restriction as trains will already be travelling at the lower speed.

GN244

The second (higher) speed restriction should be extended to commence at the termination of the preceding lower speed restriction, so that the speed restriction board for the higher speed restriction can be located at the end of the lower restriction.

D.3.2

Where a higher speed is followed by a lower speed D.3.2.1 Where the deceleration distance means that the warning board for a temporary speed restriction falls within or before a higher temporary speed restriction all of the following arrangements shall apply (see Figures D-23 and D-24): a)

The higher temporary speed restriction shall be extended to terminate at the commencement of the lower temporary speed restriction.

b)

A termination indicator for the first temporary speed restriction shall not be provided.

c)

The warning board for the second restriction, if this is within the higher temporary speed restriction, shall be positioned at the deceleration distance calculated using the speed of the first temporary speed restriction (rather than the permissible speed of the line). DD 90 – 40 40

DD 90 – 20 40

DD 40 – 20

20

20

20 T

T

90

90

40

40

(extended 40)

20

90

20

90

Figure D-23 Example of a higher TSR followed by a lower TSR (D.3.2.1) DD 90 – 40 40

DD 90 – 20 20

DD 40 – 20 40

20

20 T

T

90

90

90

40

(extended 40)

Figure D-24 Another example of a higher TSR followed by a lower TSR (D.3.2.1) GN245

Where one temporary speed restriction is followed by another which is a lower speed, the deceleration distance for the second (lower) speed restriction can be based on the speed of the preceding speed restriction, instead of the permissible speed of the line.

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Guidance on Lineside Signal Spacing and Speed Signage GN246

D.3.3

The warning board for the second speed restriction should be placed at this deceleration distance, and the first (higher) speed restriction should be extended so that it continues to the start of the following lower speed restriction. This means that trains do not accelerate from the speed of the first speed restriction before they reach the warning board for the following lower speed restriction. Where warning boards coincide D.3.3.1 Where two or more warning boards, for separate diverging routes or successive speed restrictions on the same line, are calculated to fall within 4 seconds running time of each other: a)

The warning boards shall be positioned so that the AWS magnet for the second warning board is positioned immediately after the first warning board in the direction of travel.

b)

A separate AWS magnet shall be provided for each warning board.

c)

The AWS magnet for each warning board shall be positioned in accordance with D.2.4.

GN247

The two warning boards should, where practicable, be positioned to allow the AWS magnets to be positioned at the standard distance of 180 m on the approach to each warning board. This would require the two warning boards to be 180 m apart.

GN248

Where this is not practicable, the constraints on positioning the AWS magnets in D.2.4 apply. This means that the spacing between the two warning boards should allow for the required minimum distance between the second warning board and its associated AWS magnet, and therefore is not less than 4 seconds running time, subject to a minimum of 45 m (50 yd).

GN249

To achieve this spacing, one (and in some cases both) of the warning boards should be positioned at a distance greater than the required deceleration distance from the speed indicator.

GN250

To avoid driver confusion, it is not permissible to place the warning boards closer together than the minimum distance required between the second warning board and its associated AWS magnet, or to provide only one AWS magnet for the two warning boards. D.3.3.2

Where the conditions of D.3.3.1 apply to speed restrictions on diverging routes (see Figure D-25): a)

The warning board for the straight route shall be positioned so that the driver passes it first.

b)

In the case of the divergence the WON shall specify: ‘The second warning board and associated AWS warning indication on ___ line at ___ miles ___ chains apply only to trains proceeding to ___ line.’ 30 DD 90 – 20

DD 90 – 30 20

30 90

90 #

20

30 20

> 45 m (50 yd)

Figure D-25 Example of co-incident warning boards for diverging routes (D.3.3.2)

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Guidance on Lineside Signal Spacing and Speed Signage GN251

Where temporary speed restrictions apply to different routes at a junction, the warning board for the diverging route is placed closer to the junction and positioned at the required deceleration distance.

GN252

If the required deceleration distance for the warning board for the straight route would place it within 4 seconds running time of the warning board for the diverging route (this may be before or after the warning board for the diverging route), it should be positioned on the approach to the warning board for the diverging route, at a sufficient distance to allow the appropriate positioning of the AWS magnet for the second warning board.

GN253

Where the required deceleration distance for the warning board for the straight route would place it more than 4 seconds running time, but less than 180 m, from the warning board for the diverging route, it is permissible to place it at the correct deceleration distance. The AWS magnet for the second warning board would then require to be positioned after passing the first warning board, which means it would be at less than the standard distance of 180 m. Where practicable, the warning board for the straight route should be placed at a greater distance to permit the AWS magnet for the second warning board to be placed at the standard distance of 180 m. D.3.3.3

Where the conditions of D.3.3.1 apply to successive speed restrictions on the same line, the warning boards shall be positioned in the order in which the speed restrictions are approached (see Figure D-26).

DD 90 – 30 for TSR(1) DD 90 – 20 for TSR(2) > DD 90 – 30 for TSR(1) 30 20 90

30 90

30

20 30

20

# > 45 m (50 yd)

Figure D-26 Example of successive speed restrictions on the same line (D.3.3.3) GN254

In the example shown in Figure D-26, the required deceleration distance for the first (higher) speed restriction would place its warning board beyond the warning board for the second (lower) speed restriction. To provide a logical presentation of information to the driver, the warning board for the first speed restriction is placed on the approach to the warning board for the second speed restriction, with the AWS for the second warning board positioned immediately after the first warning board.

D.4

Altering temporary speed restrictions

D.4.1

Moving temporary speed restriction limits D.4.1.1 It is permissible for the limits of a temporary speed restriction to be moved progressively along a line, provided that the commencement is not moved towards drivers in the direction of travel. Both of the following arrangements shall apply: a)

The speed indicator and termination indicator shall be repositioned as the worksite is moved, and the warning board shall be repositioned at deceleration distance from the repositioned speed indicator.

b)

The WON shall specify: ‘Moving temporary speed restriction.’

GN255

Where the worksite moves along the line in the direction of signalled movements, the temporary speed restriction can move with the worksite. The speed indicator is then repositioned as the worksite is moved, and the warning board repositioned accordingly, so that it is still at deceleration distance from the repositioned speed indicator.

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Guidance on Lineside Signal Spacing and Speed Signage GN256

A temporary speed restriction is not moved towards approaching trains, to avoid drivers being conditioned into anticipating a previous commencement location and approaching the new position of the commencement indicator at too high a speed.

GN257

On bi-directional and single lines this means that the speed indicators and warning boards should be set out for the total length of the temporary speed restriction, those for one direction being moved in the direction of traffic as the worksite changes with those for the other direction remaining in the same position. Alternatively, if the worksite contracts from both ends, it is permissible for both sets to be moved in the direction of traffic. D.4.1.2

If it is not practicable to reposition the warning board (see Figure D-27): a)

The speed indicator and associated warning indicator shall remain in the original position.

b)

The termination indicator shall be repositioned so that it indicates the end of the temporary speed restriction at all times.

90

T

20

90

Tunnel (with restricted clearance) Figure D-27

20

T

Cannot be moved inside tunnel due to limited clearance Speed indicator must remain in its original position 20 right 20

90

Moving speed restriction

Example showing a moving TSR where the warning board cannot be moved (D.4.1.2)

GN258

In the case shown in Figure D-27, although the worksite is to be moved along the line in the direction of travel, the warning board cannot be moved to a new position because of the restricted clearance tunnel. If the speed indicator was moved with the warning board remaining in the same position, this could be confusing to drivers, who might think they had missed the speed indicator, or might assume that the temporary speed restriction had been removed and the warning board left in error.

GN259

To avoid potential confusion, therefore, if the warning board cannot be moved to the appropriate new position, the speed indicator should also be left in the same position even though the start of the actual worksite has moved.

D.4.2

Withdrawing and increasing speeds of temporary speed restrictions D.4.2.1 If the implementation of a temporary speed restriction is published or notified, and then its speed is raised earlier than planned, the speed indicators, warning boards and repeater warning boards shall:

GN260

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a)

Remain in the same position until the published time and date for their removal, and

b)

Be altered to show the higher speed.

If the speed of a temporary speed restriction can be raised earlier than planned, and therefore no change to the arrangements has been published in the WON, it is permissible for the speed indicator and warning board to be altered to show the higher speed.

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Guidance on Lineside Signal Spacing and Speed Signage GN261

The raising of the speed would generally require a shorter deceleration distance, which would allow the warning board to be moved closer to the commencement of the speed restriction. However, drivers do not expect any change to the existing arrangement, and if they no longer see a warning board in the expected position, they could assume that the restriction has been removed. To avoid confusion, the warning board should remain in the original position, even though this provides excess deceleration distance for the higher speed.

D.4.2.2

If a temporary speed restriction is published or notified but then does not need to be imposed, or if it is withdrawn earlier than shown in the WON, the speed indicators, warning boards and repeater warning boards, where required, shall: a)

Be erected or retained in the published position, unless a Special Notice cancelling the restriction is issued at least 24 hours before the temporary speed restriction is planned to commence.

b)

Where erected or retained, be altered to show the permissible speed of the line or ‘Spate’ indications (see Figure D-28).

Figure D-28 Example of a TSR not imposed or withdrawn early (D.4.2.2)

GN262

If the speed of a temporary speed restriction can be removed earlier than expected, or does not need to be imposed after details have been published, drivers expect to see the warning board and speed indicator. If the warning board and speed indicator have been removed, they would be expected to assume that the restriction still applies as published, and to report that the board as missing.

GN263

Therefore, the warning board, speed indicator and any repeater warning boards should remain in the published position, but altered to show either the permissible speed or a ‘Spate’ indication (an indicator showing a single diagonal black line which informs the driver that the planned temporary speed restriction does not apply).

D.4.2.3

GN264

Where temporary speed restrictions adjoin (see D.3), the first temporary speed restriction shall only be relaxed or removed, which will leave an adjoining restriction in place, when: a)

The warning boards for the remaining temporary speed restriction have been repositioned to take account of the change, and

b)

Amended details have been published in the WON.

Where adjacent temporary speed restrictions have been implemented, as set out in D.3.1 and D.3.2, removal of the first speed restriction, or raising its speed, would result in inadequate deceleration distance for the remaining restriction, since this could now be approached at the normal permissible speed of the line.

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Guidance on Lineside Signal Spacing and Speed Signage GN265

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The first speed restriction should therefore remain in place unless revised arrangements for the remaining restriction, including the appropriate positioning of the warning board, have been published and implemented.

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Guidance on Lineside Signal Spacing and Speed Signage Appendix E Emergency Speed Restrictions The content of this appendix is mandatory.

E.1

Management of emergency speed restrictions E.1.1

A temporary speed restriction shall be implemented as an emergency speed restriction if: a)

It has not been published in the WON.

b)

It has only been published in an amendment to the WON.

c)

The actual speed restriction is slower than the speed details published in the WON, or

d)

The speed restriction applies at a time that is different to the details published in the WON.

E.1.2

The infrastructure manager shall consistently communicate details of all emergency speed restrictions to the drivers of all railway undertakings that operate over the route.

E.1.3

An emergency speed restriction shall be managed as a temporary speed restriction only after the correct details have been published in the WON.

GN266

If a temporary speed restriction (including a variation to a published temporary speed restriction) has to be imposed at short notice, for example because of an incident affecting the condition of the line, drivers will not have been advised through the WON. Although measures should be taken to advise drivers of the speed restriction, it cannot be assumed that drivers are aware of it. It is therefore necessary to manage such a restriction as an emergency speed restriction.

E.2

Provision of speed indicators, warning boards and AWS equipment E.2.1

Emergency speed restrictions shall be implemented as temporary speed restrictions, in accordance with the requirements of this standard, except that a risk assessment is not required for the disconnection of an AWS electromagnet at a signal.

E.2.2

In addition, an emergency indicator shall be positioned:

E.2.3

GN267

a)

On the approach to the AWS permanent magnet for the warning board.

b)

Not less than 180 m (200 yd) before the warning board.

c)

Not further than 400 m (440 yd) before the warning board.

An AWS permanent magnet shall be positioned on the approach to the emergency indicator (see Figure E-1).

To draw drivers’ attention to an emergency speed restriction of which they may be unaware, an emergency indicator, with an additional AWS permanent magnet, is positioned on the approach to the AWS magnet for the warning board. The AWS warning indication is intended to alert them to the presence of the emergency indicator. On observing the emergency indicator, they are reminded that particular attention should be given to the following warning board.

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Guidance on Lineside Signal Spacing and Speed Signage GN268

The erection of signs and the consequent need for trains to continue to be cautioned would be delayed by the requirement to carry out a risk assessment before the AWS magnet associated with a signal is disconnected. A risk assessment is still required when or if the ESR is changed to a TSR.

E.2.4

The emergency indicator and associated permanent magnet shall remain in place until either: a)

The relevant details have been published in the WON, or

b)

The speed restriction has been withdrawn.

#

90

max 400 m (440 yd)

20

90 90 # Emergency indicator shown positioned at minimum distance from warning board

Figure E-1 Example of arrangements for emergency speed restriction (E.2.2)

GN269

Unless it is withdrawn, the speed restriction should remain signed as an emergency speed restriction until the details have been published in the WON, when the emergency indicator and additional AWS magnet can be removed, leaving the restriction signed as a normal temporary speed restriction.

GN270

Although other methods may be employed to advise drivers of an emergency speed restriction, such as communication to the railway undertakings, who should pass the information on to drivers, or publication of a supplementary operating notice, these alternative means of communication do not have the same level of control as the WON to ensure that all drivers have received and understood them. Therefore, even when these other methods have been used to advise drivers, the speed restriction should still be signed as an emergency speed restriction until the details have been published in the regular WON.

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Guidance on Lineside Signal Spacing and Speed Signage Appendix X Deceleration Distances The content of this appendix is mandatory GRADIENT (mm/m) Initial Speed

1 in 50

1 in 67

(mph)

20R

15R

1 in 100 1 in 200 1 in 400 10R

5R

2.5R

20

155

165

180

200

210

25

220

235

260

290

303

30

295

315

350

390

35

375

402

402

40

402

443

503

45

523

604

50

523

55

602

60

Level

1 in 400 1 in 200 1 in 100 1 in 67 1 in 50 2.5F

5F

10F

15F

20F

220

238

255

295

365

402

325

345

375

402

422

523

402

402

412

422

523

644

770

443

473

503

553

604

744

986

1305

583

643

704

784

865

1066

1408

664

785

845

905

995

1086

1267

1569

2012 2046

604

664

785

845

905

995

1086

1267

1569

2046

652

710

785

845

905

995

1086

1267

1569

2046

716

776

845

929

980

1032

1097

1162

1329

1569

2046

65

775

838

910

996

1049

1102

1168

1234

1428

1730

2046

70

862

929

945

984

1004 1084

1096 1164

1150 1215

1205 1258

1276 1320

1348 1382

1520 1534

1740 1740

2046

75 80

945

984

1084

1164

1215

1258

1320

1382

1534

1740

85

1040

1102

1171

1251

1309

1354

1415

1471

1614

1788

2046 2046

90

1173

1246

1325

1419

1484

1537

1610

1674

1842

2049

2330

1750 2041

1835

1913

2113

2366

2713

2143

2245

2503

2835

3312

2041

2143

2245

2503

2835

3312

10

2046

95

1325

1409

1502

1612

1680

100

1520

1621

1735

1870

105

1520

1621

1735

1870

1960 1960

110

1520

1621

1735

1870

1960

2041

2143

2245

2503

2835

3312

1870

1960

2041

2143

2245

2503

2835

3312

2041

2143

2245

2503

2835

3312

2052

2143

2245

2503

2835

3312

115

1520

1621

1735

120

1574

1643

1735

1870

1960

125

1702

1777

1856

1944

1998

Gradients are shown as ‘R’ for rising and ‘F’ for falling. Table X-1 Deceleration distance in metres to speed restriction of 10 mph

Page 88 of 103 GK/GN0675 Issue Four September 2015

RSSB

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT (mm/m) Initial Speed

1 in 67

1 in 50

2.5F

5F

10F

15F

20F

325

345

375

402

402

402

402

402

402

443

543

805

422

443

483

523

664

885

1267

573

624

694

764

986

1287

1811

704

764

825

925

1026

1207

1489

1971

604

704

764

825

925

1026

1207

1489

1971

607

662

729

777

825

925

1026

1207

1489

1971

674

733

799

880

929

979

1042

1105

1268

1489

1971

736

796

866

950

1001

1052

1116

1180

1345

1650

2046

70

826

890

964

1053

1106

1160

1225

1291

1489

1740

2046

75

886

966

1046

1147

1207

1258

1320

1382

1534

1740

2046

80

891

966

1046

1147

1207

1258

1320

1382

1534

1740

2046

85

1013

1075

1143

1222

1275

1328

1398

1469

1609

1788

2046

90

1147

1218

1297

1389

1449

1509

1589

1670

1842

2049

2330

95

1298

1382

1473

1582

1656

1730

1820

1911

2113

2366

2713

100

1492

1593

1705

1838

1925

2012

2112

2213

2503

2835

3299

105

1492

1593

1705

1838

1925

2012

2112

2213

2503

2835

3299

110

1492

1593

1705

1838

1925

2012

2112

2213

2503

2835

3299

115

1492

1593

1705

1838

1925

2012

2112

2213

2503

2835

3299

120

1540

1608

1705

1838

1925

2012

2112

2213

2503

2835

3299

125

1670

1750

1831

1911

1971

2032

2122

2213

2503

2835

3299

(mph)

1 in 50 1 in 67 1 in 100 1 in 200 1 in 400 20R

15R

10R

5R

2.5R

25

220

235

260

290

303

30

295

315

350

390

402

35

375

402

402

402

40

402

402

463

523

45

483

543

604

50

483

543

55

560

60 65

Level

1 in 400 1 in 200 1 in 100

20

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-2 Deceleration distance in metres to speed restriction of 20 mph

RSSB

Page 89 of 103 GK/GN0675 Issue Four September 2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT (mm/m) Initial Speed

1 in 67

1 in 50

15F

20F

523

704

1066

825

1106

1609

925

1086

1348

1851

845

925

1086

1348

1851

770

847

925

1086

1348

1851

805

898

991

1142

1348

1851

892

925

1000

1075

1230

1529

1971

970

1008

1046

1121

1196

1408

1740

1971

986

1066

1126

1187

1285

1358

1534

1740

1971

905

986

1066

1126

1187

1285

1358

1534

1740

1971

1023

1089

1165

1216

1267

1312

1358

1549

1750

1971

1166

1243

1331

1389

1448

1528

1609

1790

2012

2293

1248

1329

1418

1529

1589

1650

1740

1831

2052

2313

2655

100

1440

1538

1647

1777

1864

1951

2051

2152

2434

2796

3219

105

1440

1538

1647

1777

1864

1951

2051

2152

2434

2796

3219

110

1440

1538

1647

1777

1864

1951

2051

2152

2434

2796

3219

115

1440

1538

1647

1777

1864

1951

2051

2152

2434

2796

3219

120

1485

1550

1647

1777

1864

1951

2051

2152

2434

2796

3219

125

1613

1690

1770

1871

1921

1971

2061

2152

2434

2796

3219

(mph)

1 in 50 1 in 67

1 in 100 1 in 200 1 in 400

20R

15R

10R

5R

2.5R

35

375

402

402

402

402

40

402

402

402

422

472

45

402

443

523

624

50

402

443

523

55

480

522

60

596

648

65

661

70

Level

1 in 400 1 in 200 1 in 100 2.5F

5F

10F

402

402

402

523

593

664

694

765

845

624

694

765

570

630

700

709

783

794

717

781

860

757

817

887

75

845

905

80

845

85

964

90

1098

95

30

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-3 Deceleration distance in metres to speed restriction of 30 mph GRADIENT (mm/m) Initial Speed

1 in 67

1 in 50

2.5F

5F

10F

15F

20F

583

663

744

885

1106

1569

523

583

663

744

885

1106

1569

528

583

663

744

885

1106

1569

630

668

706

754

803

932

1107

1569

648

714

759

805

865

925

1086

1328

1811

702

763

845

886

927

996

1066

1247

1529

1831

744

805

885

966

1016

1066

1146

1227

1428

1609

1831

766

812

885

966

1016

1066

1146

1227

1428

1609

1831

85

887

943

1004

1086

1126

1167

1227

1287

1428

1609

1831

90

1021

1085

1158

1247

1307

1368

1438

1509

1670

1891

2152

95

1171

1247

1332

1431

1500

1569

1649

1730

1931

2193

2515

100

1359

1453

1556

1690

1770

1851

1961

2072

2334

2676

3098

105

1359

1453

1556

1690

1770

1851

1961

2072

2334

2676

3098

110

1359

1453

1556

1690

1770

1851

1961

2072

2334

2676

3098

115

1359

1453

1556

1690

1770

1851

1961

2072

2334

2676

3098

120

1428

1509

1569

1690

1770

1851

1961

2072

2334

2676

3098

125

1569

1629

1710

1811

1851

1891

1982

2072

2334

2676

3098

(mph)

1 in 50 1 in 67

1 in 100 1 in 200 1 in 400

20R

15R

10R

5R

2.5R

45

402

402

402

463

523

50

402

402

402

463

55

402

402

426

473

60

475

518

568

65

545

593

70

648

75 80

Level

1 in 400 1 in 200 1 in 100

40

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-4 Deceleration distance in metres to speed restriction of 40 mph

Page 90 of 103 GK/GN0675 Issue Four September 2015

RSSB

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT (mm/m) Initial Speed

1 in 67

1 in 50

2.5F

5F

10F

15F

20F

402

402

402

402

422

664

461

494

528

617

740

1046

544

583

623

664

785

986

1428

704

744

804

865

1006

1247

1609

825

865

905

975

1046

1227

1428

1609

825

865

905

975

1046

1227

1428

1609

884

947

986

1026

1086

1147

1267

1428

1609

972

1046

1127

1177

1227

1287

1348

1509

1710

1931

1062

1133

1210

1308

1368

1428

1498

1569

1770

2012

2293

100

1246

1333

1448

1569

1639

1710

1810

1911

2152

2454

2877

105

1246

1333

1448

1569

1639

1710

1810

1911

2152

2454

2877

110

1246

1333

1448

1569

1639

1710

1810

1911

2152

2454

2877

115

1246

1333

1448

1569

1639

1710

1810

1911

2152

2454

2877

120

1368

1428

1489

1569

1639

1710

1810

1911

2152

2454

2877

125

1489

1549

1629

1710

1760

1811

1861

1911

2152

2454

2877

(mph)

1 in 50 1 in 67

1 in 100 1 in 200 1 in 400

20R

15R

10R

5R

2.5R

55

402

402

402

402

402

60

402

402

402

409

435

65

402

422

463

506

70

523

563

604

664

75

624

664

744

80

658

699

744

85

780

830

90

914

95

Level

1 in 400 1 in 200 1 in 100

50

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-5 Deceleration distance in metres to speed restriction of 50 mph

GRADIENT (mm/m) Initial Speed

1 in 67

1 in 50

2.5F

5F

10F

15F

20F

402

402

402

402

483

724

463

503

543

644

825

1267

613

644

704

764

905

1147

1267

653

678

721

764

905

1147

1267

780

810

841

877

914

1026

1147

1267

880

945

985

1026

1076

1127

1267

1428

1650

983

1050

1130

1178

1227

1297

1368

1529

1730

2012

1106

1187

1287

1388

1458

1529

1619

1710

1911

2213

2575

1106

1187

1287

1388

1458

1529

1619

1710

1911

2213

2575

110

1106

1187

1287

1388

1458

1529

1619

1710

1911

2213

2575

115

1127

1187

1287

1388

1458

1529

1619

1710

1911

2213

2575

120

1267

1308

1368

1428

1478

1529

1619

1710

1911

2213

2575

125

1388

1448

1509

1589

1629

1670

1720

1770

1911

2213

2575

(mph)

1 in 50 1 in 67 1 in 100 1 in 200 1 in 400 20R

15R

10R

5R

2.5R

65

402

402

402

402

402

70

402

402

402

422

442

75

463

503

543

583

80

523

551

586

628

85

640

682

728

90

774

824

95

921

100 105

Level

1 in 400 1 in 200 1 in 100

60

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-6 Deceleration distance in metres to speed restriction of 60 mph

RSSB

Page 91 of 103 GK/GN0675 Issue Four September 2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT (mm/m) Initial Speed (mph)

1 in 50 1 in 67

1 in 100 1 in 200 1 in 400

1 in 67

1 in 50

2.5F

5F

10F

15F

20F

402

402

402

443

583

925

450

469

489

536

590

925

597

624

646

668

732

808

925

774

805

834

863

966

1086

1247

20R

15R

10R

5R

2.5R

75

402

402

402

402

402

80

402

402

402

418

434

85

483

503

530

570

90

600

644

682

744

Level

1 in 400 1 in 200 1 in 100

70

95

745

805

851

925

965

1006

1056

1106

1247

1408

1609

100

945

1006

1086

1187

1237

1287

1367

1448

1629

1871

2193

105

945

1006

1086

1187

1237

1287

1367

1448

1629

1871

2193

110

945

1006

1086

1187

1237

1287

1367

1448

1629

1871

2193

115

1006

1046

1086

1187

1237

1287

1367

1448

1629

1871

2193

120

1147

1187

1247

1308

1338

1368

1408

1448

1629

1871

2193

125

1267

1328

1388

1448

1488

1529

1569

1609

1690

1871

2193

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-7 Deceleration distance in metres to speed restriction of 70 mph

GRADIENT (mm/m) Initial Speed (mph)

1 in 50 1 in 67

1 in 100 1 in 200 1 in 400

1 in 67

1 in 50

2.5F

5F

10F

15F

20F

402

402

402

402

402

422

517

540

564

619

685

770

688

712

748

785

865

966

1106

905

955

1006

1056

1106

1247

1428

1650

905

955

1006

1056

1106

1247

1428

1650

905

955

1006

1056

1106

1247

1428

1650

986

1006

1026

1056

1106

1247

1428

1650

1086

1127

1157

1187

1217

1247

1308

1428

1650

1227

1287

1317

1348

1378

1408

1489

1569

1670

20R

15R

10R

5R

2.5R

85

402

402

402

402

402

90

402

422

445

478

497

95

563

583

624

664

100

744

785

845

105

744

785

845

110

764

785

845

115

865

905

945

120

1006

1046

125

1127

1167

Level

1 in 400 1 in 200 1 in 100

80

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-8 Deceleration distance in metres to speed restriction of 80 mph

GRADIENT (mm/m) Initial Speed (mph)

1 in 50 1 in 67

1 in 100 1 in 200 1 in 400

20R

15R

10R

5R

2.5R

Level

1 in 400 1 in 200 1 in 100

1 in 67

1 in 50

2.5F

5F

10F

15F

20F

90 95

402

402

402

402

402

402

402

402

422

463

523

100

503

523

563

604

634

664

694

724

825

925

1086

105

503

523

563

604

634

664

694

724

825

925

1086

110

604

624

644

664

674

684

704

724

825

925

1086

115

704

744

764

805

815

825

845

865

905

966

1086

120

845

865

905

945

965

986

1006

1026

1086

1147

1207

125

966

1006

1046

1106

1126

1147

1177

1207

1267

1328

1408

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-9 Deceleration distance in metres to speed restriction of 90 mph

Page 92 of 103 GK/GN0675 Issue Four September 2015

RSSB

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT (mm/m) Initial Speed

1 in 50

(mph)

20R

1 in 67 1 in 100 1 in 200 1 in 400 15R

10R

5R

2.5R

110

402

412

422

443

453

115

523

543

563

583

593

120

644

664

694

724

125

785

805

835

865

Level

1 in 400 1 in 200 1 in 100

1 in 67

1 in 50

2.5F

5F

10F

15F

20F

463

468

473

493

513

533

604

614

624

654

684

724

739

754

774

795

825

865

905

885

905

930

956

1006

1056

1106

100 105

Gradients are shown as ‘R’ for rising and ‘F’ for falling Table X-10 Deceleration distance in metres to speed restriction of 100 mph The following Guidance Note Tables (X-11 - X-20) present the corresponding deceleration distances in yards for the data set out in Tables X-1 - X-10 above. GRADIENT Initial Speed

1 in 50

1 in 67 1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

20

170

180

195

215

228

25

240

255

280

315

30

320

340

380

425

35

405

440

440

40

440

484

45

572

661

50

572

55

658

60

Level

1 in 400 1 in 200 1 in 100

1 in 67

1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

2.0%F

240

258

275

320

395

440

335

355

383

410

440

461

572

440

440

451

461

572

704

968

484

517

550

605

661

814

1078

1540

550

638

703

770

857

946

1166

1540

2200

726

858

924

990

1088

1188

1386

1716

2237

661

726

858

924

990

1088

1188

1386

1716

2237

713

776

858

924

990

1088

1188

1386

1716

2237

783

849

924

1016

1072

1129

1200

1271

1453

1716

2237

65

848

916

995

1089

1147

1205

1277

1350

1562

1892

2237

70

943

1016

1098

1199

1258

1318

1395

1474

1660

1903

2237

75

1033

1076

1185

1273

1324

1375

1443

1511

1677

1903

2237

80

1033

1076

1185

1273

1324

1375

1443

1511

1677

1903

2237

85

1137

1205

1281

1368

1430

1481

1545

1609

1765

1956

2237

90

1283

1363

1449

1552

1321

1681

1756

1831

2014

2241

2548

95

1449

1541

1643

1763

1838

1914

2003

2092

2311

2587

2967

100

1662

1773

1897

2045

2144

2232

2343

2455

2737

3100

3622

105

1662

1773

1897

2045

2144

2232

2343

2455

2737

3100

3622

110

1662

1773

1897

2045

2144

2232

2343

2455

2737

3100

3622

115

1662

1773

1897

2045

2144

2232

2343

2455

2737

3100

3622

120

1721

1797

1897

2045

2144

2232

2343

2455

2737

3100

3622

125

1861

1943

2030

2126

2185

2244

2343

2455

2737

3100

3622

10

Gradients are shown as ‘R’ for rising and ‘F’ for falling. GN Table X-11 Deceleration distance in yards to speed restriction of 10 mph

RSSB

Page 93 of 103 GK/GN0675 Issue Four September 2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

25

240

255

280

315

335

30

320

340

380

425

440

35

405

440

440

440

40

440

440

506

45

528

594

661

50

528

594

55

612

664

60

737

65

Level

1 in 400 1 in 200 1 in 100

1 in 67

1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

2.0%F

355

383

410

440

440

440

440

440

440

484

594

880

461

484

528

572

726

968

1386

572

627

682

759

836

1078

1407

1981

770

836

902

1012

1122

1320

1628

2155

661

770

836

902

1012

1122

1320

1628

2155

724

797

850

902

1012

1122

1320

1628

2155

802

874

962

1016

1071

1140

1208

1387

1628

2155

805

871

947

1039

1095

1150

1220

1290

1471

1804

2237

70

903

973

1054

1152

1210

1269

1340

1412

1628

1903

2237

75

969

1056

1144

1254

1320

1375

1443

1511

1677

1903

2237

80

974

1056

1144

1254

1320

1375

1443

1511

1677

1903

2237

85

1108

1176

1250

1336

1394

1452

1529

1606

1765

1956

2237

90

1254

1332

1418

1519

1585

1650

1738

1826

2014

2241

2548

95

1419

1511

1611

1730

1811

1892

1990

2090

2311

2587

2697

100

1632

1742

1865

2010

2105

2200

2310

2420

2737

3100

3608

105

1632

1742

1865

2010

2105

2200

2310

2420

2737

3100

3608

110

1632

1742

1865

2010

2105

2200

2310

2420

2737

3100

3608

115

1632

1742

1865

2010

2105

2200

2310

2420

2737

3100

3608

120

1684

1759

1865

2010

2105

2200

2310

2420

2737

3100

3608

125

1826

1914

2002

2090

2155

2222

2321

2420

2737

3100

3608

20

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-12 Deceleration distance in yards to speed restriction of 20 mph

Page 94 of 103 GK/GN0675 Issue Four September 2015

RSSB

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

35

405

440

440

440

440

40

440

440

440

461

516

45

440

484

572

682

50

440

484

572

55

525

571

60

652

65

723

70

Level

1 in 400 1 in 200 1 in 100

1 in 67 1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

2.0%F

440

440

440

572

770

1166

572

649

726

902

1210

1760

759

837

924

1012

1188

1474

2024

682

759

837

924

1012

1188

1474

2024

623

689

766

842

926

1012

1188

1474

2024

709

775

856

868

880

982

1084

1249

1474

2024

784

854

940

975

1012

1094

1176

1345

1672

2155

828

893

970

1061

1102

1144

1226

1308

1540

1903

2155

75

924

990

1078

1166

1231

1298

1405

1485

1677

1903

2155

80

924

990

1078

1166

1231

1298

1405

1485

1677

1903

2155

85

1054

1119

1191

1274

1330

1386

1435

1485

1694

1914

2155

90

1201

1275

1359

1456

1519

1584

1671

1760

1958

2200

2508

95

1365

1453

1551

1672

1738

1804

1903

2002

2244

2529

2904

100

1575

1682

1801

1943

2038

2134

2243

2353

2662

3058

3520

105

1575

1682

1801

1943

2038

2134

2243

2353

2662

3058

3520

110

1575

1682

1801

1943

2038

2134

2243

2353

2662

3058

3520

115

1575

1682

1801

1943

2038

2134

2243

2353

2662

3058

3520

120

1624

1695

1801

1943

2038

2134

2243

2353

2662

3058

3520

125

1764

1848

1936

2046

2101

2155

2254

2353

2662

3058

3520

30

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-13 Deceleration distance in yards to speed restriction of 30 mph GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

45

440

440

440

506

572

50

440

440

440

506

572

55

440

440

466

517

60

519

566

621

65

596

649

709

70

709

768

834

75

814

880

968

80

838

888

968

85

970

1031

90

1117

95

Level

1 in 400 1 in 200 1 in 100

1 in 67 1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

2.0%F

638

725

814

968

1210

1716

638

725

814

968

1210

1716

577

638

725

814

968

1210

1716

689

731

772

825

878

1019

1211

1716

781

830

880

946

1012

1188

1452

1981

924

969

1014

1089

1166

1364

1672

2002

1056

1111

1166

1253

1342

1562

1760

2002

1056

1111

1166

1253

1342

1562

1760

2002

1098

1188

1231

1276

1342

1407

1562

1760

2002

1187

1266

1364

1429

1496

1573

1650

1826

2068

2353

1281

1364

1457

1565

1640

1716

1803

1892

2112

2398

2750

100

1486

1589

1702

1848

1936

2024

2145

2266

2552

2926

3388

105

1486

1589

1702

1848

1936

2024

2145

2266

2552

2926

3388

110

1486

1589

1702

1848

1936

2024

2145

2266

2552

2926

3388

115

1486

1589

1702

1848

1936

2024

2145

2266

2552

2926

3388

120

1562

1650

1716

1848

1936

2024

2145

2266

2552

2926

3388

125

1716

1781

1870

1981

2024

2068

2167

2266

2552

2926

3388

40

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-14 Deceleration distance in yards to speed restriction of 40 mph

RSSB

Page 95 of 103 GK/GN0675 Issue Four September 2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph) 50

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

55

440

440

440

440

440

60

440

440

440

447

476

65

440

461

506

553

70

572

616

661

726

75

682

726

814

902

80

720

764

814

902

85

853

908

967

1036

90

1000

1063

1144

1232

95

1161

1239

1323

100

1363

1458

105

1363

110

1363

115

Level

1 in 400 1 in 200 1 in 100

1 in 67 1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

440

440

440

440

461

726

504

540

577

675

809

1144

595

638

681

726

858

1078

1562

770

814

879

946

1100

1364

1760

946

990

1066

1144

1342

1562

1760

946

990

1066

1144

1342

1562

1760

1078

1122

1188

1254

1386

1562

1760

1287

1342

1407

1474

1650

1870

2112

1430

1496

1562

1638

1716

1936

2200

2508

1584

1716

1792

1870

1979

2090

2353

2684

3146

1458

1584

1716

1792

1870

1979

2090

2353

2684

3146

1458

1584

1716

1792

1870

1979

2090

2353

2684

3146

1363

1458

1584

1716

1792

1870

1979

2090

2353

2684

3146

120

1496

1562

1628

1716

1792

1870

1979

2090

2353

2684

3146

125

1628

1694

1781

1870

1925

1981

2035

2090

2353

2684

3146

2.0%F

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-15 Deceleration distance in yards to speed restriction of 50 mph

GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

65

440

440

440

440

440

70

440

440

440

461

483

75

506

550

594

638

80

572

603

641

687

85

700

746

796

90

846

901

95

1007

100 105

Level

1 in 400 1 in 200 1 in 100

1 in 67 1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

440

440

440

440

528

792

506

550

594

704

902

1386

670

704

770

836

990

1254

1386

714

741

788

836

990

1254

1386

853

886

920

959

1000

1122

1254

1386

962

1033

1077

1122

1177

1232

1386

1562

1804

1075

1148

1236

1288

1342

1418

1496

1672

1892

2200

1210

1298

1407

1518

1594

1672

1771

1870

2090

2420

2816

1210

1298

1407

1518

1594

1672

1771

1870

2090

2420

2816

110

1210

1298

1407

1518

1594

1672

1771

1870

2090

2420

2816

115

1232

1298

1407

1518

1594

1672

1771

1870

2090

2420

2816

120

1386

1430

1496

1562

1616

1672

1771

1870

2090

2420

2816

125

1518

1584

1650

1738

1781

1826

1881

1936

2090

2420

2816

2.0%F

60

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-16 Deceleration distance in yards to speed restriction of 60 mph

Page 96 of 103 GK/GN0675 Issue Four September 2015

RSSB

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

75

440

440

440

440

440

80

440

440

440

457

85

528

550

580

623

90

656

704

746

95

815

880

100

1033

105

Level

1 in 400 1 in 200 1 in 100

1 in 67 1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

2.0%F

440

440

440

484

638

1012

475

492

513

535

586

645

1012

653

682

706

731

801

884

1012

814

846

880

912

944

1056

1188

1364

931

1012

1055

1100

1155

1210

1364

1540

1760

1100

1188

1298

1353

1407

1495

1584

1781

2046

2398

1033

1100

1188

1298

1353

1407

1495

1584

1781

2046

2398

110

1033

1100

1188

1298

1353

1407

1495

1584

1781

2046

2398

115

1100

1144

1188

500

1353

1407

1495

1584

1781

2046

2398

120

1254

1298

1364

1430

1463

1496

1540

1584

1781

2046

2398

125

1386

1452

1518

1584

1627

1672

1716

1760

1848

2046

2398

70

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-17 Deceleration distance in yards to speed restriction of 70 mph

GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

85

440

440

440

440

440

90

440

461

487

523

95

616

638

682

726

100

814

858

924

105

814

858

110

836

858

115

946

120 125

Level

1 in 400 1 in 200 1 in 100

1 in 67 1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

2.0%F

440

440

440

440

440

461

544

565

591

617

677

749

842

752

779

818

858

946

1056

1210

990

1044

1100

1155

1210

1364

1562

1804

924

990

1044

1100

1155

1210

1364

1562

1804

924

990

1044

1100

1155

1210

1364

1562

1804

990

1033

1078

1100

1122

1155

1210

1364

1562

1804

1100

1144

1188

1232

1265

1298

1331

1364

1430

1562

1804

1232

1276

1342

572

1440

1474

1507

1540

1628

1716

1826

80

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-18 Deceleration distance in yards to speed restriction of 80 mph

GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

Level

1 in 400 1 in 200 1 in 100

1 in 67 1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

2.0%F

90 95

440

440

440

440

440

440

440

440

461

506

572

100

550

572

616

661

693

726

759

792

902

1012

1188

105

550

572

616

661

693

726

759

792

902

1012

1188

110

661

682

704

726

737

748

770

792

902

1012

1188

115

770

814

836

880

891

902

924

946

990

1056

1188

120

924

946

990

1033

1055

1078

1100

1122

1188

1254

1320

125

1056

1100

1144

1210

1231

1254

1287

1320

1386

1452

1540

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-19 Deceleration distance in yards to speed restriction of 90 mph

RSSB

Page 97 of 103 GK/GN0675 Issue Four September 2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage GRADIENT Initial Speed

1 in 50

1 in 67

1 in 100 1 in 200 1 in 400

(mph)

2.0%R

1.5%R

1.0%R

0.5%R

0.25%R

110

440

451

461

484

495

115

572

594

616

638

120

704

726

759

792

125

858

880

913

946

Level

1 in 400 1 in 200 1 in 100

1 in 67 1 in 50

0.25%F

0.5%F

1.0%F

1.5%F

2.0%F

506

512

517

539

561

583

649

661

671

682

715

748

792

808

825

846

869

902

946

990

968

990

1017

1045

1100

1155

1210

100 105

Gradients are shown as ‘R’ for rising and ‘F’ for falling GN Table X-20 Deceleration distance in yards to speed restriction of 100 mph

Page 98 of 103 GK/GN0675 Issue Four September 2015

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Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage Appendix Y Key to Symbols Used in this Standard xx

Section of line showing permissible speed (xx mph) Section of line with (yy mph and zz mph)

differential

permissible

AWS magnet for permissible speed (“P” indicates permanent magnet only)

P

xx

yy

yy/zz xx

xx yy

warning

speeds

indicator

Section of line showing (in upright type) permissible speed (xx mph) (in italics) temporary speed restriction (yy mph) Section of line with differential temporary speed restriction (yy mph and zz mph) Permissible speed indicator (xx indicates speed displayed) Permissible speed warning indicator (xx indicates speed displayed) Speed indicator marking commencement of temporary speed restriction (yy indicates speed displayed)

T

Termination indicator for temporary speed restriction

yy

DD yy–xx

Warning board for temporary speed restriction (yy indicates speed displayed) Position of warning board at deceleration distance (DD) from speed indicator (for speed reduction from yy mph to xx mph) Repeater warning board for temporary speed restriction

Emergency indicator (for emergency speed restriction) AWS magnet for signal Portable AWS magnet for temporary speed restriction (permanent magnet only) AWS cancelling indicator Spate indicator

# Distance between warning board and associated AWS equipment

GN271 RSSB

There is no guidance associated with the above appendix. Page 99 of 103 GK/GN0675 Issue Four September 2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage Definitions Actual signalling braking distance (ASD) The actual distance between a signal displaying the first cautionary aspect and the signal displaying the associated stop aspect. Attainable speed (as applicable to this document) The maximum speed that any permitted type of rolling stock can achieve over a specific section of line, where it is not possible for any rolling stock authorised to operate on the line to attain the permissible speed. Attainable speed can be used as the basis of deceleration distance calculations for temporary speed restrictions or to enable the driver to bring the train to a stand at a stop signal. Deceleration distance The minimum distance at which a warning indicator (for a permissible speed) or a warning board (for a temporary or emergency speed restriction) shall be positioned approaching the start of the change in speed to which it applies, in order to ensure that all trains have sufficient warning to be able to conform to the required reduction in speed. Differential speed A permissible speed or speed restriction applicable to a particular type of train, where different values of speed are applicable to different types of trains over the same section of line. Differential speeds include: a)

Standard differential speed − Two values of permissible speed, or two different speed values for a temporary speed restriction, each of which is applicable to one of two standard categories of trains, as defined in the Rule Book.

b)

Non-standard differential speed − A permissible speed for a specific type of train, which is different from that for other types of trains on the same section of line. This comprises ‘Permissible speed indicators with letters’ and ‘Enhanced permissible speed indicators’ as described in the Rule Book. Non-standard differential speeds are not applicable to temporary or emergency speed restrictions.

Emergency speed restriction A speed restriction not shown in the Weekly Operating Notice (WON), or which is more restrictive than shown, or which applies at a time other than that shown in the WON. Enhanced permissible speed The permitted speed (higher than the permissible speed) over a section of line which applies to a specific type of train operating at cant deficiencies in excess of those permitted at the permissible speed (see GE/RT8012 and GC/RT5021). Excess signal spacing The distance by which the actual signalling braking distance exceeds the minimum signalling braking distance. Lineside operational safety sign Lineside operational safety signs include speed indicators, warning indicators and emergency indicators, as depicted in GI/RT7033: Lineside Operational Safety Signs, Appendix A, sections AD, AE and AF. Miniature permissible speed indicator A reduced size indicator in accordance with GI/RT7033, Appendix A, sections AD and AE showing the permissible speed(s) over a section of line.

Page 100 of 103 GK/GN0675 Issue Four September 2015

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Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage Minimum signalling braking distance (MSD) The calculated minimum distance between a signal displaying the first caution aspect and the signal displaying the associated stop aspect. Overrun Passing the end of movement authority (the end of movement authority is the point where a train is required to come to a stand on completion of a signalled movement). On lines signalled with lineside signals, the conventional terminology for an overrun is a signal passed at danger (SPAD). The definition includes both failure to come to a stand at a signal at danger and starting from rest against a signal at danger. Permissible speed The authorised maximum speed over a section of line, either for all trains or (where differential speeds are applied) for specific types of trains, as set out in the Sectional Appendix. Permissible speed indicator An indicator in accordance with GI/RT7033 showing the permissible speed(s) over a section of line. Permissible speed warning indicator An indicator in accordance with GI/RT7033 showing warning of a reduction of permissible speed over a section of line. Signal Throughout this document the word ‘signal’ shall be understood to include any lineside sign that performs the function of a signal. Signalling braking distance (as applied to this document) The distance between the signal exhibiting the first caution aspect and the signal at which the train is required to stop. Spate indicator (Speed Previously Applied Terminated Early) A trackside indicator which informs the driver that a temporary speed restriction has been withdrawn earlier than published or has not been applied. Temporary speed restriction A speed, less than the permissible speed, applied for a pre-planned period not normally exceeding six months. Weekly Operating Notice (WON) The Weekly Operating Notice (WON) is the official printed notice which includes advice to drivers of temporary speed restrictions and alterations to permissible speeds. GO/RT3215: Requirements for WON, PON and Sectional Appendix, details requirements for the format and contents of the WON. Other defined terms are included in GK/GN0802: Glossary of Signalling Terms.

RSSB

Page 101 of 103 GK/GN0675 Issue Four September 2015

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage Abbreviations and Acronyms ASD

Actual signalling braking distance

AWS

Automatic warning system

ESR

Emergency speed restriction

ETCS

European Train Control System

LUL

London Underground Limited

MSD

Minimum signalling braking distance

PSR

Permanent speed restriction

PON

Periodic Operating Notice

SPAD

Signal passed at danger

Spate

Speed Previously Applied Terminated Early

TSR

Temporary speed restriction

TVM

Transmission voice-machine

WON

Weekly Operating Notice

Page 102 of 103 GK/GN0675 Issue Four September 2015

RSSB

Uncontrolled When Printed Document comes into force on 05/12/2015 Supersedes GKGN0675 Iss 3 on 05/12/2015

Guidance on Lineside Signal Spacing and Speed Signage References The Catalogue of Railway Group Standards gives the current issue number and status of documents published by RSSB. This information is also available from www.rgsonline.co.uk. RGSC 01 RGSC 02

Railway Group Standards Code Standards Manual

Documents referenced in the text Railway Group Standards GC/RT5021 Track System Requirements GE/RT8000 Rule Book GE/RT8012 Controlling the Speed of Tilting Trains Through Curves GE/RT8037 Signal Positioning and Visibility GE/RT8075 AWS and TPWS Interface Requirements GE/RT8270 Assessment of Compatibility of Rolling Stock and Infrastructure GI/RT7033 Lineside Operational Safety Signs GK/RT0045 Lineside Signals, Indicators, and Layout of Signals GK/RT0075 Lineside Signal Spacing and Speed Signage GM/RT2041 Braking System Requirements and Performance for Trailer Coaching Stock GM/RT2042 Braking System Requirements and Performance for Traction Units GM/RT2043 Braking System and Performance for Freight Trains GM/RT2044 Braking System Requirements and Performance for Multiple Units GM/RT2045 Braking Principles for Rail Vehicles GO/RT3215 Requirements for the Weekly Operating Notice, Periodical Operating Notice and Sectional Appendix RSSB documents GK/GN0802 Glossary of Signalling Terms

RSSB

Page 103 of 103 GK/GN0675 Issue Four September 2015