DieselShip's Online Content Library

Q6. The force acting normal to the centerline plane of a rudder is given by the expression:

Fn = 15.5 A v2 α newtons

Where, A = Rudder area (m2)

v = Ship speed (m/s)

α = Rudder helm angle (degrees)

A ship travelling at a speed of 20 knots has a rudder configuration as shown in Fig Q4. The center of effort for areas A1 and A2 are 32% of the width from their respective leading edges. The rudder angle is limited to 35º from the ship's centerline.

Calculate EACH of the following:

(a) The diameter of the rudder stock required for a maximum allowable stress of 77 MN/m2;

(b) The drag component of the rudder force when the rudder is put hard over at full speed.