Rudder horn

The rudder horn is the fixed structural support that carries a semi-spade rudder, a cantilever extension of the hull aft of the propeller that houses the lower rudder bearing (pintle) and reacts the rudder side force and bending. It is either a heavy welded plate fabrication or a steel casting integrated into the stern frame. The horn carries the rudder weight and the hydrodynamic load between the upper bearing in the rudder trunk and the lower pintle bearing, so its fatigue detailing at the connection to the shell is a class survey focus. A pure spade rudder has no horn; its full load goes through the rudder stock.