To turn a single screw vessel short round.
A consideration of what has already been stated will show that a ship with a right handed propeller can be turned more easily with her head going to starboard than in the other direction. When necessary to turn short round put the rudder to starboard, and the engines full speed ahead. The screw race will press against the rudder, even if the vessel has no headway, and she will cant to starboard. Before she gathers too much headway the engines should be reversed to full speed astern, the helm being shifted accordingly so as to obtain the benefit of the suction current. Before she gathers too much sternway go full speed ahead again with rudder to starboard and so on, alternately until round. It is advisable to have an anchor ready for dropping when turning short round in narrow channels and to know that there is sufficient depth of water when manoeuvring close to banks.
To turn a twin screw vessel short round.
This is done by going ahead on one and astern on the other; the bow of the ship then turns towards that side on which the screw is going astern. By regulating the speeds of the propellers so as to prevent the vessel gathering headway, the ship can be made to turn round in her own length, but this is a slow process. A more rapid swing can be achieved by adjusting propeller speeds to cause the ship to move ahead and astern alternately, if there is sufficient space available. The rudder should be kept hard over in the direction of the turn. If the starboard screw is right-handed and the port one left-handed, the transverse thrust of both screws will assist in turning the ship short round in either direction.
