CONTROLLABLE PITCH PROPELLER :

ADVANTAGES :-

1) Improved and safer manoenvring

a) quicker speed of response ;

b) thrusts infinitely variable between full ahead and full astern ;

c) no stops and starts ; full utilisation of engine power;

d) stopping time and distance of travel after stopping is reduced.

2) Optimum pitch setting for fouled hulls improves efficiency of power and fuel
consumption.

3) Vibration may be reduced by altering pitch and engine revolutions in contrast to
revolution Control only.

4) Reduced cylinder liner wear and improved life of both engine and stern tube bearings
(constant rpm and no stops and starts for astern operation).

5) Simplified main machinery if uni - directional prime movers are used (particularly
control systems and reduction gears)

6) Permits use of engine driver auxiliaries.

7) Reduces air starting capacity requirements.

8) Easier to carry out engine trials.

DISADVANTAGES ;-

1) Higher initial cost.

2) High cost of overhaul and survey.

3) Increased risk of breakdown.

4) Poor steering with blades in neutral (transverse thrusters often fitted).

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