CHAPTER 2 



SHIP DESIGN AND CONSTRUCTION 



As ships have increased in size and com- 

 plexity, plans for building them have become 

 more detailed and more numerous. Today only 

 meticulously detailed plans and well conceived 

 organization, from the designers to the men 

 working in the shops and on the ways, can pro- 

 duce the ships required for the Navy. 



After intensive research, many technical ad- 

 vances have been adopted in the design and con- 

 struction of warships. These changes were 

 brought about by the development of welding 

 techniques, by the rapid development in air- 

 craft, submarines, and weapons, and by develop- 

 ments in electronics and in propulsion plants. 



This chapter presents information concern- 

 ing basic ship design considerations, ship flo- 

 tation, basic ship structure, ship compartmen- 

 tation, and the geometry of the ship. 



BASIC DESIGN CONSIDERATIONS 



Combat efficiency is the prime requisite of 

 warships. Some important factors contributing 

 to combat efficiency are sea-keeping capabili- 

 ties, maneuverability, and ability to remain in 

 action after sustaining combat damage. 



Basic considerations involved in the design 

 of naval ships include the following: 



1. Cost .— The initial cost is important in 

 warship design, but it is not the only cost 

 consideration. The cost of maintenance and 

 operation, as well as the cost and availability 

 of the required manning, are equally impor- 

 tant considerations. 



2. Life Expectancy .— The life expectancy of 

 a ship is limited by ordinary deterioration in 

 service and also by the possibility of obsoles- 

 cence due to the design of more efficient ships. 



3. Service .— The service to be performed 

 substantially affects the design of any ship. 



4. Port Facilities . — The port facilities 

 available in the normal operating zone of the 

 ship affect the design to some extent. Dockyard 

 facilities available for drydocking and main- 

 tenance work must be taken into consideration. 



5. Prime Mover .— The type of propelling 

 machinery to be used must be considered from 

 the point of view of the required speed of the 

 ship, the location in the ship, space and weight 

 requirements, and the effect of the machinery 

 on the center of gravity of the ship. 



6. Special Considerations.— Special consid- 

 erations such as the fuel required, the crew to 

 be carried, and special weapons are factors 

 which restrict the designer of a naval ship. 



Naval ships are designed for maximum sim- 

 plicity that is compatible with the requirements 

 of service. Naval ships are designed as simply 

 as possible in order to lower building and oper- 

 ating costs and in order to ensure greater avail- 

 ability of construction facilities. 



The following operating considerations affect 

 the size of a naval ship: 



1. Width and Length of Canal Locks and 

 Dock Facilities . These considerations obviously 

 have an effect on the size of ships that must 

 use the canals or dock facilities, 



2. Effect of Speed . — For large ships, speed 

 may be maintained with a smaller fraction of 

 displacement devoted to propulsion machinery 

 than is the case for smaller ships. Also, large 

 ships lose proportionately less speed through 

 adverse sea conditions. 



3. Effect of Radius of Action . — An increas- 

 ing cruising radius may be obtained by in- 

 creasing displacement without increasing the 

 fraction of displacement allotted to fuel and 

 stores. If the fraction of displacement set 

 aside for fuel and stores is increased, some 

 other weight must be decreased. Since the hull 



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