All About Steamers - Ship Handling Principles

Jack Gallagher's wonderful photograph of CalMac's "Bute" at Wemyss Bay on January 10, 2006

ALL ABOUT STEAMERS Ship Handling Principles Because of their ‘fixed’ paddle-wheels, only being able to go ‘forward-or- backwards’, paddle steamers have to put their helm over and swing their bow slightly out as they come alongside piers. As the bow of the ship comes across the end of a pier, the heaving line for the bow rope is thrown to the waiting piermen and then, as the ship’s bow begins to swing out, it following that the after part of the ship and the stern are then being brought ever closer to the pier, the heaving lines for the stern, then ‘waist’, ropes can then be more easily caught by the piermen. For manoeuvring purposes, it is perhaps useful to think of all twin and indeed triple screw ships as single-screw ships until their engines are all driving in the same direction and the following little bit of theory should therefore be of interest to anyone ignorant of the general principles of steering and controlling screw driven vessels, pleasure steamers and motorboats alike. The first effect of ‘putting the helm over’, trying to change direction, when the ship or boat is going ahead, is that the bow actually goes off in the opposite direction to that in which one wants the ship to go and it takes two or three ship lengths along the original course before she 1

will start to turn. By this time, the ship’s bow will have turned about three ‘points’, about 30 degrees, towards the new course, the stern of the ship continuing to drag round for a further two or three ship lengths along the original course before it finally follows the ship's bow. In theory, if a danger ‘dead ahead’ has to be avoided, one must alter course at least some six ship lengths before it in order that it is cleared. Two ships on potentially colliding courses must alter their courses ‘timeously’ indeed and, although one may gain a few extra seconds by easing down the ships’ speeds before any potential collision (and of course somewhat lessening the force of any impact), it should be clearly understood that the speed at which the ship is travelling, when her course is changed, does not greatly affect the distance along her original course which she will take before actually turning off on to her new course and clearing her original course ! High speed e.g. in a small motor yacht may be helpful but her hull will still slide along her original course, as above and ‘over-steering’ may actually even force her further into danger till she clears her old course. The effect of the ship’s propellor(s) is as important as the effect of her rudder(s). Apart from MacBrayne’s first ever twin-screw steamer, the 1878-built “Flowerdale”, which very unusually had inward-turning propellors, all the other Clyde and West Highland twin-screw ships had their propellors outward-turning when going ahead, the starboard engine turning right and the port engine turning left when going ahead. The converse happening in the case of a left-turning port engine, the following explanation of the right-turning starboard engine may be of interest. It has the effect that, the engine going astern from rest, the ship’s stern will go immediately to port even with a full starboard rudder on and the ship will only begin to go to starboard as she gathers way, given a full port rudder, from rest and going astern, the ship’s stern will be thrown rapidly port. There is a widespread ignorance of the effect on a ship’s steering when her engine(s) are suddenly reversed while the ship is going ahead and the assumption that the ship will continue to answer her helm in the usual way as she continues to forge ahead, her propellor(s) in reverse and gradually slowing her down, is indeed not the case as new forces affect the rudder and the afterbody of the ship from the very moment when her engine(s) is/are reversed. Following the case of right-turning (ahead) starboard engine, the ship’s rudder kept ‘amidships’ and the starboard engine suddenly reversed, from full ahead to full astern, the ship’s head will fall off immediately to starboard and the ship will gain ground and begin to slide ‘to the right’. If the helm of a ship is put hard over to port as her starboard engine is suddenly reversed, from full ahead to full astern, the ship’s head will usually, but not very rapidly nor very far, go to port but will then begin to swing to starboard and the ship’s head, her rudder still ‘hard-aport’, will fall off more or less to starboard. But, if the helm of a ship is reversed, from full ahead to often than not, will swing to the propellor is going astern,

put hard over to starboard as her starboard engine is suddenly full astern, the ship’s head will go to starboard and then, more port ! The slower the ship or boat is going ahead and the faster the more likely it is that her head will swing to port ! 2

In the case of the ship going astern, her starboard, right-turning, engine going ahead and her helm ‘amidships’, the ship’s stern should move to starboard but there is no guarantee that her head may actually set to pay off in one direction rather than the other ! In the same situation, the ship going astern, her starboard engine going ahead and her helm put ‘hard-a-starboard’, it will be found that her stern will go very decidedly to port. With her helm ‘hard-a-port’, her stern, most commonly, would be likely to go to starboard. A ship or boat has a right-handed (ahead) propellor can always turn easily and rapidly to starboard in a confined space, turning to port taking more space and time. In coming alongside a pier (or another ship), it is indeed bad seamanship to make the mistake of keeping too much speed on and then relying on the engine(s) going full astern to bring the ship to a stop at the appropriate point. The engines (and the engineers) may fail to act promptly and the suddeness of going astern throws an undue strain on the machinery (especially the crankshafts) and the ship’s rudder fastenings and the sudden going astern throws the ship suddenly to one side or another according to the ‘handedness’ of the propellor(s). In a tideway too, particular care must be taken not to catch the tide on the ‘off’ bow as it may actually push the bow into and under the pier or against the other ship. Changes in water density can catch the unwary and the “Maid of Cumbrae” crashed expensively into Gourock Pier because of a hidden fresh water outfall between the regular pier berths. Another ‘Maid’ skipper demonstrated the effect of the ‘fresh water phenomenon’ one winter night coming up the coast from Largs to Wemyss Bay, heavy rain having put the burn at Manor Park Hotel into spate and the helmsman of the ‘Maid’ being able to spin the wheel from ‘hard-a-port’ to ‘hard-a-starboard’ without there being any effect on the direction of the ship’s heading till we re-entered near 100% salt water again. ‘Docking Telegraphs’ On the paddle steamers, orders were transmitted to the ‘waist ropemen’, located at main deck level on the after end of the paddle-wheel sponsons, by means of a series of bell signals operated from the ‘Docking Telegraphs’ on the bridge wings 1 bell, “Throw Line”, the heaving-line itself normally being usually thrown after the stern heaving line and both being thrown by a seaman immediately above the waist ropeman from the upper deck of the sponson; 2 bells, “Make Fast”; 3 bells, “Slack Away” and 4 bells, “Let Go”, all these signals too being audible to the engineer on the near-by engine control platform. The ship’s fore and aft ‘Docking Telegraphs’, these operated from the bridge wings, also had ‘answering handles’ ringing back acknowledgements from bow and stern, their ‘face plates’ sequentially reading, from ‘port-to-starboard’, “Make Fast”, “Come On Deck”, “Haul In”, “Throw Line”, “Hold On”, “ALL CLEAR”, “Stand By”, “Slack Away”, Look Out for Fender”, “Slow” and “Let Go”. The first ‘Docking Telegraphs’, simply an adaptation of the engine-telegraphs, were installed on the 1889 “Caledonia (I)”, she built by John Reid, grand-nephew of the builder of the first “Comet (I)”, at Port Glasgow and the complementary ‘bell-system’ to the paddle 3

steamer ‘waist ropemen’ on the sponsons was essentially just a variation on the old ‘knocker’ system used before the introduction of the engine-room telegraphs. Bow Rudders In the cases of the “Duchess of Hamilton”, “Queen Mary/II” and the paddle steamer “Jeanie Deans”, she too being fitted with a bow rudder after taking up her somewhat shortlived service on The Thames as the “Queen of The South”, the forward bow ‘Docking Telegraph’ was used to give orders to the helmsman steering the ship astern from the bow, their vision aft being totally obscured by the ships’ superstructures and funnels. On these occasions, with two black balls hung vertically from the cross-trees on one of the ships’ masts, the orders on the aft-facing ‘face-plate’ forward ‘Docking Telegraph’ translated “ALL CLEAR” as “Midships”; “Make Fast”, on the port side of the telegraph, as “Hard-a-Starboard’ and, conversely “Let Go”, on the starboard side of the telegraph as “Harda-Port”, each division of the telegraph ‘face-plate’ corresponding to the application of about 15° of rudder. Turbines, Twin-Screws and Telegraphs While the paddle steamers were all fitted with ‘double-handled’ Engine Room Telegraphs, the handles locked and thus moving simultaneously on command and there being no ‘answering handles’ for the engineers to acknowledge or confirm orders from and to the bridge, the turbines and motor-ships were all fitted with ‘answering telegraphs’ rung back by the engineers as the bridge orders were implemented. For manoeuvring purposes, the turbines, even with three propellor shafts, were treated as twin-screw ships - the first ‘twin-screw’ ship was built by Captain John Stevens of Phoenix, Arizona around 1804 - 1806. On the ‘triple-screw’ turbines, the centre ‘ahead-only’ turbine and propellor shaft being shut down by means of the main stop valve wheel and the outer ‘ahead’ and ‘stern’ turbines then opened and shut down as necessary by their own individual stop valves and, the ship clearing away from the piers, the main stop valve wheel was opened to the centre, high-pressure ‘ahead’ turbine, it too then admitting steam to the two outer shaft ‘ahead’ turbines. While MacBrayne’s ships operated the deep-sea practice of giving a double “Full Ahead” ring on the telegraphs once clear of piers, this was not done on the Clyde ships, mainly because of the frequently short time intervals between pier calls. Paddle Wheels, ‘Floats’ and Shafts In the early years of the first steamers, these frequently racing each other to beat their rivals to the next pier and often manned by incompetent engineers and masters, there were often problems with the steel paddle main shafts cracking and fracturing, the initial steel strength deteriorating quickly through crystallisation brought about by the shafts’ vibrations and not helped by the persuasion of many engineers to suddenly try and put the engines astern without waiting for the engine (and the paddle wheels) to properly stop their ahead movement. Of paddle wheels themselves, the ‘floats’ fitted to the early and sea-going steamers, such as those crossing The Atlantic, were ‘fixed’ and then, in 1829, one Elijah Galloway invented the ‘feathering’ paddle-floats, these ‘moveable floats’, pivoting on bearings on the radial arms 4

and actuated by rods fixed to bearings on the outside of the paddle wheel to allow each float to enter the water at an acute angle and immerse properly in the water as the wheel turned, an arrangement which not only increased speed but also reduced the ship’s wash which could damage shorelines and river banks. While most shipowners, thinking it better for ‘shock distribution’, opted for eight ‘floats’ on each paddle wheel, the Gourock-based Caledonian Steam Packet Company ships generally had but seven ‘floats’ per wheel, the ‘floats’ being often of elm, rather than steel as, should they hit any floating objects, they could break up (and be quickly replaced) without causing any structural damage to the paddle wheels. The Clyde and other British coastal paddle steamers’ paddle wheels were relatively small in comparison to the size of those favoured for American side and stern-wheelers. Though being run on trial at nearly 59 revolutions per minute, today’s “Waverley (IV)” rarely needs to exceed 44 r.p.m. to keep or catch up on her timetabled sailings, by comparison, some of Russia’s river paddle ships, having even smaller paddle wheels, operate at 160 r.p.m. ! Steam Whistles Arriving and departing from busy piers often necessitated using the ship’s ‘whistle’ - 1 blast, going to starboard (right); 2 blasts, going to port (left) and 3 blasts indicating that the ship was going astern. The first ever recorded ship’s steam whistle is noted to have been fitted in 1837 to the “King Philip” operating on the Fall River in America.

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