What is Balance Type Rudder used on ships?

The concept of a balanced rudder involved the shifting of the centre of rotation of the rudder to point approximately 1/2 of the way from the forward end to the after end. This meant that when the rudder was turned, the flow of water past the ship actively worked on the forward third to increase the angle of deflection, whereas the same flow acted on the after 1/2 to reduce the angle.

1. When 30% to 40% of the area is forward of the turning axis there is no torque on the rudder stock at certain angles.
2. At some angle of rudder, it is balanced. i.e., torque is zero, to keep rudder at that angle.
3. Axis of rotation lies between 0.2 L and 0.37 L.