Question

(a) List the variables which affect the force on a rudder. (6)

(b) A triangular bulkhead is 7 m wide at the top and has a vertical depth of 8 m. Calculate the load on the bulkhead and the position of centre of pressure if the bulkhead is flooded with sea water on only side: (10)

(i) To the top edge

(ii) With 4 m head to the top edge.

Answer 1

when a rudder is turned from the centreline plane, to any angle, a force acts on the rudder, given by,

$$F=kAV^2N$$

Where,

k = Constant
A = Area of rudder in m2
V = Ship's speed in m/s

The constant is dependent on size of rudder, rudder angle and density of water.

Variables affecting force on rudder:

Rudder angle
Density of water
Ship speed

These are the three variables, while all other are constant parameters i.e.

Area of rudder
Size of rudder.

✓ Verified Model Answer (Text Solution)

Variables affecting force on rudder: