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Q3. With reference to a keyless propeller designed for hydraulic (wet) fit and withdrawal:

(a) describe, with the aid of a sketch, how the propeller is fitted to the tail shaft; (6)

(b) state TWO advantages compared to a dry fit; (2)

(c) explain how the thrust is transmitted without the use of a key and keyway. (2)

Q12. With reference to large fixed bladed propellers:

(a) describe, with the aid of a sketch, EACH of the following:

(i) the effect of hull fouling; (3)

(ii) operation in clean hull, ballast condition. (3)

(b) explain why fitting a light propeller may be beneficial. (4)

Q3. With reference to podded thrusters for main propulsion:

(a) distinguish between podded and azimuthing thrusters; (4)

(b) explain the meaning of thruster and tractor propellers, stating ONE advantage of tractor units; (4)

(c) explain what is meant by tandem podded thrusters. (2)