DieselShip's Online Content Library

Q8.  (a) With respect to a ships propeller, explain the term thrust deduction.  (3)

(b) The following data were obtained during a ships acceptance trials:

Ship speed = 15.4 knots

Delivery power = 2500 kW

Effective power = 1730 kW

Thrust = 274 kN

Propeller efficiency = 64%

Apparent slip = 5%

Calculate EACH of the following:

(i) The thrust deduction factor; (3)

(ii) The Taylor wake fraction; (5)

(iii) The true slip; (3)

(iv) The hull efficiency. (2)