ABSTRACT
Rudders and propeller arrangements have evolved through to 'Pod' propulsion units alongside increased engine efficiency. While jet propulsion has moved into the high-speed craft markets, with multiple hull designed vessels becoming the norm. Semi-Balanced 'Mariner'-Type Rudder is a very popular rudder for modern tonnage, especially for the container-type vessel and twin-screw vessels. The term 'semi-balanced' refers to the amount of surface area forward of the turning axis. If the proportion of surface area is less than 20 per cent forward of the axis, then the rudder is said to be semi-balanced. Our seafaring personnel have had to change to manage new facilities. The demands of weather and natural conditions have not altered but ship handlers have been forced to adapt vessel movement, with larger tonnage and increased technology. A very widely used rudder, especially in vessels engaged on short voyages such as ferries and roll on–roll off (ro-ro) ships.
