Rudder

The foil(s) used to steer a vessel. A rudder has a Blade, the part which acts on the water, and a Stock above it to transmit torque from Tiller or steering gear. The lower extremity of the blade is the Heel, and the upper extremity of the stock is the Head. A Lifting rudder has a pivoted blade that swings up to reduce its Draught. The blade is then fitted between Cheeks, which are in turn fitted to the stock. A rudder may be of several kinds, notably outboard or inboard. The transom-hung rudder is outboard and easily accessible: its hangings are the simple Pintle and Gudgeon. The inboard rudder’s stock passes through a trunk or tube, at the bottom of which there may be a watertight gland similar to that used with a propeller shaft. A Spade rudder stands in clear water, away from Keel or Skeg, an arrangement which may minimise drag but which leaves the rudder exposed to stray ropes, painters or plastic bags. A Balanced rudder is one which has some of its area ahead of the pivotal axis, thus reducing loads on the tiller. Something between ten and fifteen percent of the total blade area is enough to have ahead of the hinge line .