Training Report On Ship Designing

Report on Summer Training Garden Reach Shipbuilders and Engineers Ltd

Submitted by: Sonaljit Mukherjee

Roll No: 04NA3001

Indian Institute of Technology Kharagpur Department of Ocean Engineering and Naval Architecture

Training in Central Design Office Working in Tribon: Introduction: Hazards of Ship Building Ship building is a very complex business. The time between order and delivery is very short, which implies that a huge amount of tasks has to be performed in parallel. To perform these tasks it is required to have good tools for coordinating and managing the complex flow of information between everyone involved.

Introduction to Tribon Tribon is a 3D Product Model is a naval architecture program originally developed by Kockum Computer Systems (KCS) for designing commercial and naval vessels. KCS was spun off from Kockums shipyards as an independent company, later renamed Tribon Systems, which was in turn acquired by Aveva. Tribon is actually a family of programs that create and refer to a common set of databases containing the design details of the ship. Together, these databases are used to depict a 3D model of the ship, with embedded information for all of the parts of the design, from ship structural elements to pipe segments to equipment. Tribon Technology has been used in ship building industries for the past 40 years. Its number 1 objective has been to provide the world’s ship builders with unique software solutions to increase their efficiency. It has continuously improved quality, saved cost and shortened delivery lives. Over 260 ship builders and design agents in 39 countries rely on Tribon applications.

Developed in Cooperation Tribon M3 has been developed in close cooperation with the market leading ship builders around the world. The demands and needs of these ship builders formed the foundation for the entire development. Specific solutions have been created and tested to meet specific needs. Tribon supports the complete ship building process from concept to delivery.

Tribon M3 is a design and information system created to fit the specific needs of ship building and offshore industries. Tribon M3 supports the ship building process, where the goal is to efficiently produce and handle all the information from concept to delivery. When using Tribon.com, shipyards have access to accurate and complete supplier product information, which helps them shorten the time spent on searching for, downloading and integrating component information during the design process.

Each Tribon M3 application handles the design from the initial stage through the exact details needed for production. Information registered at an earlier stage of design can be refined as the project progresses. Where possible, Tribon M3 will check that the design meets the design rules and is practical. This helps prevent the kind of mistakes which might otherwise not be discovered until production is underway. Easy access to design information means that several designers can work in parallel and coordinate their tasks.

Production benefits Tribon M3 provides many benefits in production. Minimization of rework is built on close attention to accuracy in all stages of design and production so that things can be done right the first time. Tribon M3 has practical realistic features to promote an accurate way of working. Built into Tribon M3 is an extensive knowledge of the entire ship building process, including high standard production information for all types of parts. Tribon PIM technology makes product data available to all parties involved so that they can get the information they need, when they need it. All data relevant to parts manufacturing and assembly is found in the Tribon PIM and can be extracted in the format each individual user requires. Each assembly or installation activity can have its own document containing precisely the information to perform that particular activity. The result is that, draftsmen or workshop planners can prepare and print work instructions just in time.

Create once, Refine and use many times

One of the basic features of Tribon Technology is to create information once and use it many times. Designers create a basic Tribon PIM (Product Information Model) which is enhanced with details by the engineers. All documentation for materials acquisition and planning is derived from Tribon PIM. Drawings, reports etc, for manufacturing of plate parts, pipe spools, ventilation ducts, cables, pipe and cable hangers etc. In addition, drawings and assembly data to feed assembly welding robots are all extracted from the Tribon PIM.

Re-Use of Design Tribon M3 contains new tools for copying parts of existing ship models to a new model – its being called as the Tribon Project Copy Functionality. This makes it possible to re-use existing data. These tools automatically rename objects object references. They also disconnect associative references from the “mother” ship and re-establish them correctly in the receiving project.

These new functions will dramatically improve the possibilities to save design time through an efficient re-use of existing data. They can also be used to study different alternative ship designs.

Contract Design Tribon M3 provides a wide range of tools in all disciplines to make the Contract Design in a structured way that allows full details to be extracted for pricing and planning. The instant access to accurate product information from system and equipment suppliers using Tribon.com reduces the time spent on searching and waiting for supplier information needed to develop the contract design. A number of different alternatives can be evaluated to find the best solution. Finally the best design can be effectively presented to the client, reflecting the skills of the company.

Contract Design:    

Specification Equipment Selection Outfit Hull

When an offer becomes an order, the design information can immediately be reused and refined without being re-created as the project develops and progresses. The better the design is, the less risk will be there in the tender. The result is greater accuracy with the best possible price. – and a reduced risk regarding what the profit will be at the end of the day.

Tribon M3 Applications list (for Contract Design) Tribon.com has functions for  Global database of suppliers and technical product information  Searching for suppliers and their products

 Downloading of technical information for products including 3D volumes  Technical enquiries to suppliers for additional product information

Tribon M3 Initial Design has functions for Preliminary hullform definition Distortion of existing hull forms Definitions of decks and bulkheads Compartmentation Resistance and Powering Calculations Maneuvering, propulsion, and seakeeping calculations Stability and capacity calculations(including grain and containers)  Calculation of structural loads  Lines plan  Continuous Flooding Simulation       

Tribon M3 Drafting has functions for  Creation of General Arrangement Drawings

Tribon M3 Pipe has functions for  Specification of components for pipe systems  Diagrams for pipe systems

Tribon M3 cable has functions for  Diagrams for Electrical systems

Tribon M3 Design Manager has functions for  Estimates of Block Weights  Design review by shipyard management, classification societies and ship owners  Walk through

Tribon M3 Data Management has functions for Access control, approval and release of design data

Basic Design Tribon M3 effectively supports the basic design phase during which major equipment selection, general arrangements, systems design, spaces allocation and structural design are given final approval by classification societies and shipowners. Basic Design  Equipment selection  Outfit  Hull By using Tribon M3, the equipment selection process is enhanced significantly. Moreover the technical data for each piece of equipment can be downloaded into the design and technical enquiries can be sent to the suppliers for more information. Tribon M3 is useful for a variety of design scenarios, one of them being when the entire or parts of the design. The system is an aid in making important decisions regarding the preliminary definition and arrangement of principal structural members, and it provides the framework for associated design guidance.

More Accurate Calculations

Tribon M3 generates classification drawings, steel material estimates, equipment lists, weld lengths and weights and centre of gravity reports. The preliminary structural definition developed in the basic design phase can be used for detailed design and preparation of production information. The use of Tribon PIM in the basic design phase leads to more accurate calculations and better estimates of materials and work content.

Interfaces to FEM softwares In Tribon M3, analysis tools are integrated into the basic design process. Through the XML based interface formats available with Tribon M3, links are built to software packages from classification societies and for FEM based strength and vibration calculations.

Tribon.com Basic Design has functions for Design of Longitudinal structural members Calculation of section modulus Design of transversal structural members Placement of main equipments and creation of machinery arrangement drawings  Automatic drawing generation from the Tribon PIM  Division of steel structure into main building blocks    

 Weight and centre of gravity reports  Steel material estimation  Export of data to FEM calculations

Detailed Design In the detailed design phase Tribon M3 provides an efficient system for concurrent design. Therefore many designers can work in parallel creating a detailed layout for compartments, defining systems and making the details of the steel structure.

Efficient information handling Detailed Design    

Equipment selection Outfit Hull Production Information

During detailed design phase, designers can find detailed supplier information on Tribon.com – for major equipments as well as fittings and minor components that need to be selected in this phase of design.

Higher quality and less re-work Tribon M3 comprises a powerful feature to model in a drawing. All kinds of drawing views in a model objects derived from Tribon PIM are linked to the actual model. This enables changes in the model to be carried out via the drawing, which in turn ensures complete consistency between Tribon PIM and all related drawings. Another important feature is collision control – the function of carrying out a spatial check of arrangements in compartments and on decks. In Tribon M3 the detailed arrangements can be checked at any time for colliding objects. This will minimize the number of clashing parts during the assembly of work.

Tribon M3 Hull has functions for  Detailed planar and curved steel structures  Manufacturing information for steel parts(excess, bevel and shrinkage)  Automatic parts numbering  Penetration holes for outfitting  Calculations of painting areas  Plate nesting with burning sketch and NC information  Profile nesting with sketch and NC information

Training in Hull Shop and Shipbuilding Shop

The work in modern hull shop is mainly comprised of construction of blocks, from plates, and attaching longitudinal and transverse stiffeners. This is accomplished mainly by welding. The blocks can be the various positions for the ship, namely superstructures, bulkheads in the midship, and fore and aft regions. After the construction of these blocks, they are transported to the dry dock with the help of cranes. The Crane Capacity available for Fabrication Shop-50 MT, Machine Shop-75 MT and for assembly Shop-100 MT. Bottom Structure: The centre line of the bottom structure is located on the keel. The commonest form of keel is the flat plate keel, which is being fitted in the ship.

When grounding is required, this type of keel is suitable with its massive scantlings, but there is problem of the increased draft with no additional cargo capacity. If a double bottom is fitted the keel is almost inevitably of the flat plate type, bar keels often being associated with open floors, where the plate keel may also be fitted. Double Bottom Structure: Double bottoms may be framed longitudinally or transversely, but since the ship’s length exceeds 120 mts it is considered desirable to adopt longitudinal framing.

Floors: Vertical transverse plate floors are provided both where the bottom is transversely and longitudinally framed. At the ends of bottom tank spaces and under the main bulkheads, watertight or oil tight plate floors are provided. These are made watertight or oil tight by closing any holes in the plate floor and welding collars around any members which pass through the floors. Elsewhere ‘solid plate floors’ are fitted to strengthen the bottom transversely and support the inner bottom. These run transversely from the continuous centre girder to the bilge, and manholes provided for access through the tanks and lightening holes are cut in each solid plate floor. Also, small air and drain holes may be drilled at the top and bottom respectively of the solid plate floors in the tank spaces. The spacing of the solid plate floors varies according to the loads supported and local stresses experienced. Decks: The weather decks of ships are cambered, the camber being parabolic or straight. There may be advantages in fitting horizontal decks in some ships, particularly if containers are carried and regular cross-sections are desired. Short lengths of internal deck or flats are as a rule horizontal. Decks are arranged in plate panels with transverse or longitudinal stiffening, and local stiffening in way of any openings. Longitudinal deck girders may support the transverse framing, and deep transverses the longitudinal framing.

Deck Plating: The heaviest deck plating will be found abreast the hatch openings of the strength deck. Plating which lies within the line of the hatch openings contributes little to the longitudinal strength of the deck and it is therefore appreciably lighter. As the greatest longitudinal bending stresses will occur over the midship region, the greatest deck plate thickness is maintained over 40 per cent of the length amidships, and it tapers to a minimum thickness permitted at the ends of the ship. Deck Stiffening: Decks may be framed transversely or longitudinally but outside the line of openings it is preferred that longitudinal framing should be adopted for the strength deck. When the decks are longitudinally framed the scantlings of the longitudinals are dependent on their spacing, the length of ship, whether they are inside or outside the line of hatch openings, their span and the deck loading. Deck transverses support the longitudinals, and these are built from a deep web plate with flange or welded face flat, and are bracketed to the side frame. Superstructures and Deckhouses: Superstructures might be defined as those erections above the freeboard deck which extend to the ship’s side or almost to the side. Deckhouses are those erections on deck which are well within the line of the ship’s side. Both structures are of importance in the assignment of the load line as they provide protection for the openings through the freeboard deck. Of particular importance in this respect are the end bulkheads of the superstructures, particularly the bridge front which is to withstand the force of any seas shipped. The bridge structure amidships or the poop aft are, in accordance with statutory regulations, provided as protection for the machinery openings. It is possible however to dispense with these houses or superstructures and increase considerably the scantlings of the exposed machinery casing; but in other than very small vessels it is unlikely that such an arrangement would be adopted. Unless an excessive sheer is provided on the uppermost deck it is necessary to fit a forecastle forward to give added protection in a seaway. Each structure is utilized to the full, the after structure carrying virtually all the accommodation in modern ships. The crew may be located all aft in the poop structure or partly housed in any bridge structure with the navigating spaces. Passenger liners have considerable areas of superstructures covering tiers of decks.

and these will house the majority of passengers and some of the crew. Of great structural importance is the strength of the vessel where superstructures and deckhouses terminate and are non-continuous. At these discontinuities, discussed in Chapter 8, large stresses may arise and additional strengthening will be required locally as indicated in the following notes on the construction. Long superstructures exceeding 15 per cent of the ship’s length and extending within 50 per cent of the vessel’s length amidships receive special consideration as they contribute to the longitudinal strength of the ship, and as such must have scantlings consistent with the main hull strength members.

Majority of these tasks are accomplished by welding and cutting. Mainly Gas Metal Arc Welding is used in the process. A wire or electrode is connected to a source of electric supply with a return lead to the plates to be welded. If the electrode is brought into contact with the plates and electric current flows in the circuit. By removing the electrode a short distance from the plate, so that the electric current is able to jump the gap, a high temperature electrical arc is created. This will melt the plate edges and the end of the electrode if this is of the consumable type. Electric power sources vary DC generators or rectifiers with variable or constant voltage characteristics being available as well as AC transformers with variable voltage characteristics for single or multiple operations. The latter are most commonly used in shipbuilding. In manual welding electrodes, the core wire normally used for mild steel electrodes is rimming steel. This is ideal for wire drawing purposes, and elements used to ‘kill’ steel such as silicon or aluminum tend to destabilize the arc, making ‘killed’ steels unsuitable. Coatings for the electrodes normally consist of a mixture of mineral silicates, oxides, fluorides, carbonates, hydrocarbons, and powdered metal alloys plus a liquid binder. After mixing, the coating is then extruded onto the core wire and the finished electrodes are dried in batches in ovens.