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Q7. A ship 135 m long displaces 13500 tonne. The shaft power required to maintain a speed of 16 knots is 5984 kW, and the propulsive coefficient based upon shaft power is 0.65.

Wetted surface area = 2.6 √∆L

Propulsive coefficient = ep/sp

Values of the Froude friction coefficient for Froude’s Formula are given in Fig Q5, with speed in m/s and speed index (n) = 1.825

Calculate the shaft power for a geometrically similar ship which has a displacement of 18520 tonne and which has the same propulsive coefficient as the smaller ship, and is run at the corresponding speed.