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Q7. A ship 137 m long displaces 13716 tonne. The shaft power required to maintain a speed of 15 knots is 4847 kW, and the propulsive coefficient based upon shaft power is 0.67.

wetted surface area = 2.58

propulsive coefficient = ep/ sp

Values of the Froude friction coefficient for Froude’s Formula are given in Fig Q7, 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 18288 tonne and which has the same propulsive coefficient as the smaller ship, and is run at the corresponding speed. (16)