helm port

The advantage arising from this form of rudder and mode of hanging it is this, that the hole through the counter or stern of the ship which is called the helm port, is wholly closed up by the head of the rudder passing through it, with almost a close joint, as the line of the centre of the pintles or hinges is made to pass through the centre of the rudder head, whereby the round head of the rudder becomes a large pintle before the fore side of the rudder head, and the rudder, necessarily working on the centre of the pintles, required that the hole through the counter of the ship for the reception of the head of the rudder should be made large enough to allow of the rudder working over with a radius equivalent to the diameter of the rudder head; the large helm port which was thence formed was found to be the source of leakage in the ship at all times, and, in the event of the loss of rudder at sea, the large aperture endangered the safety of the vessel.