Page 325 - Practical Ship Design

Machinery Selection 283

A good estimate of the space requirements for such items should be passed to
the marine engineer at an early stage in the design and it is obviously very
important that weight and cost estimates by both naval architect and marine
engineer are prepared to a standard demarcation.
A wise naval architect will ensure that his marine engineering colleagues are
closely involved in the specification and arrangement of any major items of
machinery even if these are to be fitted well away from the engine room.
Experienced engineering advice on such items as bow or stern thrusters can be
invaluable.

9.7 OTHER PROPULSION DEVICES

The high fuel prices of the eighties stimulated studies into the use of so-called
“free” energy sources and this chapter seems the most appropriate place in this
book to discuss these.

9.7. I Wind power
Proposals for the use of wind power have varied from fairly conventional designs
derived from the sailing ships of former days, with either fore and aft schooner or
square rigs such as Dyna ship, solid aerofoils such as those designed by Walker
Wingsail, revivals of the Fletner rotor ship, the use of wind turbines, or even kites.
Some proposals have been based on the use of wind power as the main
propulsive force when there is a satisfactory wind blowing; in other proposals the
wind is used to assist a conventional main engine, either increasing the ship’s
speed or reducing the power delivered by the engine and therefore improving the
fuel consumption.
One of the most pleasing uses of wind power has been on a number of small
cruise ships, where as well as saving fuel costs the fact that the passengers get the
exhilaration of being under sail is a major sales point to those who cruise on these
ships. That these vessels can also have an attractive appearance must be a further
plus point for a cruise liner.
Some guidelines for successful wind power designs are:
(i) It must be possible to build the wind powered ship to a size not too
different from that of the conventional vessel with which it must compete.
If it cannot, it will lose out on the economics of size.
(ii) The design must be such that cargo handling is as easy as it is on a
competing ship. For general cargo it has therefore either to be suitable for
containers, which seems likely to be very difficult, or have a competitive
cargo handling system, which may be equally difficult to achieve. For bulk