Page 319 - Introduction to Naval Architecture

12 Ship design

Ship design is perhaps the most demanding of all engineering tasks. A
ship is a large, complex artifact. In this it can be likened to a large civil
engineering product which must float and move on the interface
between water and air. It is usually much larger than an aircraft and
often has many more people on board. The ship designer seldom has
the advantage of a prototype whereas the aircraft or land vehicle
designer usually has several prototypes during the trials of which, any
design faults can be detected and rectified. In aircraft for instance, one
or more complete fuselages will be tested to destruction to determine
strength and fatigue qualities. On the other hand the naval architect
has the advantage of many 'type' ships already at sea from which he can
learn if he is so minded.
This chapter shows how the various aspects of naval architecture
discussed earlier, are brought together in the design process. It is not
possible to describe that process in detail but the aim is to give the
reader a feel for its nature; what is important, why compromise is
necessary and why certain vessels work out the way they do. In
particular, those aspects of the design and the design process that
impinge upon the safety of the ship will be outlined. Before the
designer can start the owner must specify the nature of the ship
needed, the areas of operation and any special considerations.
The designer then attempts to create an effective, efficient said safe ship,
To be effective it must meet the owner's needs as laid down in the ship
requirements. To be efficient it must carry out its functions reliably and
economically. To be safe it must be able to operate under the expected
conditions without incident and to survive more extreme conditions
and accidents within an agreed level of risk. It must not be unduly
vulnerable to the unexpected.

EFFECTIVENESS
Design requirements
The owner must specify what is required of a new vessel. It may have to
operate to tight schedules, use specific ports, use the same machinery
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