|left A ship's wheel is composed of eight cylindrical wooden
spokes (though sometimes as few as six or as many as ten or twelve depending on the wheel's size and how much force is needed to turn it) shaped like
balusters and all joined at a central wooden
hub or
nave (sometimes covered with a brass
nave plate) which houses the
axle. The square hole at the centre of the hub through which the axle runs is called the
drive square and was often lined with a brass plate (and therefore called a
brass boss, though this term was used more often to refer to a brass hub and nave plate) which was frequently etched with the name of the wheel's manufacturer. The outer rim is composed of sections each made up of stacks of three
felloes, the
facing felloe, the
middle felloe, and the
after felloe. Because each group of three felloes at one time made up a quarter of the distance around the rim, the entire outer wooden wheel was sometimes called the
quadrant. Each spoke runs through the middle felloe, creating a series of handles beyond the wheel's rim. One of these handles/spokes was frequently provided with extra grooves at its tip which could be felt by a helmsman steering in the dark and used by him to determine the exact position of the rudder—this is the
king spoke, and when it pointed straight upward the rudder was believed to be dead straight to the hull. The completed ship's wheel and associated axle and pedestals might even be taller than the person using it. The wood used in construction of this type of wheel was most often either
teak or
mahogany, both of which are very durable tropical
hardwoods capable of surviving the effects of salt water spray and regular use without significant decomposition. Modern design—particularly on smaller vessels—can deviate from the template. ==Mechanism==