24.Rudder pintle

    The rudder is supported by pintles which fit into the gudgeons.The upper part of

each pintle is tapered and fits into a similar taper in the rudder gudgeons.The pintle

is pulled hard against the taper by means of a large nut with some suitable locking

device , such as a lock nut or split pin. A brass liner is fitted round the lower part of

the pintle. Lignum vitae or laminated plastic is dovetailed into the sternframe gudgeon to provide a bearing surface for the pintle ,allowing the pintle to turn but

preventing any side movement.A head is fitted to the upper pintle to prevent undue

vertical movement of the rudder.This is known as a locking pintle.The bottom

pintle is known as a bearing pintle since it rests on a hardened steel pad shaped to

suit the bottom of the pintle.A hole is drilled in the gudgeon, with a smaller hole in

the bearing pad, to allow for the free circulation of water which acts as a lubricant

for the lignum vitae ,and allows the bearing pad to be punched out when worn.

    The rudder is turned by means of a stock which is of forged steel, opened out into a palm at its lower end.The stock is carried through the rudder trunk and keyed to the steering engine.It is essential that the centerline of stock and centerline of

pintles are in the same line, otherwise the rudder will not turn.A watertight gland must be fitted round the stock where it penetrates the deck.Many ships,however, are fitted with rudder carriers which themselves form watertight glands.The bear-ing surfaces are formed by cast iron cones, the upper cone being fitted to the rudder stock.As the bearing surfaces of the lower pintle wear, the weight of the rudder will be taken by the carrier.and therefore the vertical wear down should be very small.