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A ship's wheel or boat's wheel is a device used aboard a
ship A ship is a large watercraft, vessel that travels the world's oceans and other Waterway, navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally disti ...
,
boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size or capacity, its shape, or its ability to carry boats. Small boats are typically used on inland waterways s ...
,
submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...
, or
airship An airship, dirigible balloon or dirigible is a type of aerostat (lighter-than-air) aircraft that can navigate through the air flying powered aircraft, under its own power. Aerostats use buoyancy from a lifting gas that is less dense than the ...
, with which a
helmsman A helmsman or helm (sometimes driver or steersman) is a person who steering, steers a ship, sailboat, submarine, other type of maritime vessel, airship, or spacecraft. The rank and seniority of the helmsman may vary: on small vessels such as fis ...
steer Steer(s) or steering may refer to: Animals * Steer or bullock, castrated male cattle * Ox, a bovine (usually a steer) used as a draft animal People * Steer (surname) * Steers (surname) Places * Steer Creek (West Virginia), a tributary ...
s the vessel and controls its course. Together with the rest of the steering mechanism, it forms part of the helm (the term ''helm'' can mean the wheel alone, or the entire mechanism by which the rudder is controlled). It is connected to a mechanical, electric servo, or hydraulic system which alters the horizontal angle of the vessel's
rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...
relative to its hull. In some modern ships the wheel is replaced with a simple toggle that remotely controls an electro-mechanical or electro-hydraulic drive for the rudder, with a rudder position indicator presenting feedback to the helmsman.


History

Until the invention of the ship's wheel, the helmsman relied on a
tiller A tiller or till is a lever used to steer a vehicle. The mechanism is primarily used in watercraft, where it is attached to an outboard motor, rudder post, rudder post or stock to provide leverage in the form of torque for the helmsman to turn ...
—a horizontal bar fitted directly to the top of the
rudder post A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw and ...
—or a whipstaff—a vertical stick acting on the arm of the ship's tiller. Near the start of the 18th century, a large number of vessels appeared using the ship's wheel design, but historians are unclear when the approach was first used.


Design

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 A baluster () is an upright support, often a vertical moulded shaft, square, or lathe-turned form found in stairways, parapets, and other architectural features. In furniture construction it is known as a spindle. Common materials used in its c ...
and all joined at a central wooden hub or ''nave'' (sometimes covered with a brass ''nave plate'') which houses the
axle An axle or axletree is a central shaft for a rotation, rotating wheel and axle, wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In ...
. 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 Teak (''Tectona grandis'') is a tropical hardwood tree species in the family Lamiaceae. It is a large, deciduous tree that occurs in mixed hardwood forests. ''Tectona grandis'' has small, fragrant white flowers arranged in dense clusters (panic ...
or
mahogany Mahogany is a straight- grained, reddish-brown timber of three tropical hardwood species of the genus ''Swietenia'', indigenous to the AmericasBridgewater, Samuel (2012). ''A Natural History of Belize: Inside the Maya Forest''. Austin: Universit ...
, both of which are very durable tropical
hardwood Hardwood is wood from Flowering plant, angiosperm trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal ecosystem, boreal latitudes they are mostly deciduous, but in tropics and subtropics mostl ...
s 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

The steering gear of earlier ships' wheels sometimes consisted of a double wheel where each wheel was connected to the other with a wooden ''spindle'' that ran through a ''barrel'' or ''drum''. The spindle was held up by two ''pedestals'' that rested on a wooden ''platform'', often no more than a grate. A ''tiller rope'' or ''tiller chain'' (sometimes called a ''steering rope'' or ''steering chain'') ran around the barrel in five or six loops and then down through two ''tiller rope/ chain slots'' at the top of the platform before connecting to two
sheave Sheave without a rope A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft. A pulley may have a groove or grooves between flan ...
s just below deck (one on either side of the ship's wheel) and thence out to a pair of pulleys before coming back together at the tiller and connecting to the ship's rudder. Movement of the wheels (which were connected and moved in unison) caused the tiller rope to wind in one of two directions and angled the tiller left or right. In a typical and intuitive arrangement, a forward-facing helmsman turning the wheel ''counter''clockwise would cause the tiller to angle to starboard and therefore the rudder to swing to port causing the vessel to also turn to port (see animation). Having two wheels connected by an axle allowed two people to take the helm in severe weather when one person alone might not have had enough strength to control the ship's movements. When at the full extent of travel, the wheel and rudder are said to be "hard over", hence the order "hard
port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...
/
starboard Port and starboard are Glossary of nautical terms (M-Z), nautical terms for watercraft and spacecraft, referring respectively to the left and right sides of the vessel, when aboard and facing the Bow (watercraft), bow (front). Vessels with bil ...
" given by
Captain Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader or highest rank officer of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police depa ...
/
Officer of the Watch Watchkeeping or watchstanding is the assignment of sailors to specific roles on a ship to operate it continuously. These assignments, also known at sea as ''watches'', are constantly active as they are considered essential to the safe operation ...
.


Gallery

File:Britannia Yacht Club Commodore Boardroom.jpg,
Britannia Yacht Club The Britannia Yacht Club (BYC) is a private social club, yacht club, and tennis club based in Britannia, a neighbourhood in Ottawa, Ontario, Canada. It was founded in 1887 by a group of cottagers. The BYC is located on an extension of land at ...
's Commodore Boardroom features a ship's wheel table File:Annunciator.jpg, USS ''LST-325'' ship's wheel and
engine order telegraph An engine order telegraph or E.O.T., also referred to as a Chadburn, is a communications device used on a ship (or submarine) for the pilot on the bridge to order engineers in the engine room to power the vessel at a certain desired speed. C ...
, the latter also referred to in the
US Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...
as the
lee helm There are two different meanings to the term lee helm depending on whether one is discussing sailboats or motorized ships. Sailboats Lee helm is the tendency of a sailboat to turn away from the wind while under sail. It is the opposite of weather ...
File:US Navy 050823-N-9076B-001 Electrician's Mate 1st Class Aaron Walker speaks to chief petty officer selectees as he stands at the helm of USS Constitution in Boston.jpg, U.S. Navy personnel aboard , by the ship's wheel File:Kitee.vaakuna.svg, Ship's wheel pictured in the coat of arms of
Kitee Kitee (; ) is a town and a municipality of Finland. It is located in the province of Eastern Finland and is part of the North Karelia region, about south of Joensuu and about northeast of Lappeenranta. The municipality has a population of () ...


See also

*
Steering engine A steering engine is a power steering device for ships. History Prior to the invention of the steering engine, large steam-powered warships with manual steering needed huge crews to turn the rudder rapidly. The Royal Navy once used 78 men hauli ...
*
Steering wheel A steering wheel (also called a driving wheel, a hand wheel, or simply wheel) is a type of steering control in vehicles. Steering wheels are used in most modern land vehicles, including all mass-production automobiles, buses, light and hea ...
*
Tiller A tiller or till is a lever used to steer a vehicle. The mechanism is primarily used in watercraft, where it is attached to an outboard motor, rudder post, rudder post or stock to provide leverage in the form of torque for the helmsman to turn ...


References


External links

{{Sailing ship elements Control devices Watercraft components