Ship's wheel

Last updated September 04, 2024

A ship's wheel or boat's wheel is a device used aboard a water vessel or airship, in which a helmsman steers the vessel and control 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^[1]). It is connected to a mechanical, electric servo, or hydraulic system which alters the horizontal angle of the vessel's rudder 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 horizontal bar fitted directly to the top of the rudder post—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.^[2]

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 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

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 sheaves 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 counterclockwise 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).^[3]^: p.152 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/starboard" given by Captain/Officer of the Watch.

Gallery

Britannia Yacht Club's Commodore Boardroom features a ship's wheel table
USS LST-325 ship's wheel and engine order telegraph, the latter also referred to in the US Navy as the lee helm
U.S. Navy personnel aboard USS Constitution, by the ship's wheel
Ship's wheel pictured in the coat of arms of Kitee

Related Research Articles

A wheel is a rotating component that is intended to turn on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing labor in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel, and flywheel.

A tandem bicycle or twin is a form of bicycle designed to be ridden by more than one person. The term tandem refers to the seating arrangement, not the number of riders. Patents related to tandem bicycles date from the mid 1880s. Tandems can reach higher speeds than the same riders on single bicycles, and tandem bicycle racing exists. As with bicycles for single riders, there are many variations that have been developed over the years.

An axle or axletree is a central shaft for a rotating 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 former case, bearings or bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type of axle is referred to as a spindle.

<span class="mw-page-title-main">Spoke</span> Part of a wheel extending radially from the hub to the rim

A spoke is one of some number of rods radiating from the center of a wheel, connecting the hub with the round traction surface.

A bicycle wheel is a wheel, most commonly a wire wheel, designed for a bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels.

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. On an airplane, the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end. Often rudders are shaped so as to minimize hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels. In typical aircraft, the rudder is operated by pedals via mechanical linkages or hydraulics.

Steering is the control of the direction of motion or the components that enable its control. Steering is achieved through various arrangements, among them ailerons for airplanes, rudders for boats, cylic tilting of rotors for helicopters, and many more.

<span class="mw-page-title-main">Tiller</span> Lever used to steer a vehicle, typically on boats

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 or stock to provide leverage in the form of torque for the helmsman to turn the rudder. A tiller may also be used in vehicles outside of water, and was seen in early automobiles.

A steering wheel is a type of steering control in vehicles.

<span class="mw-page-title-main">Wheelwright</span> Person who builds or repairs wooden wheels

A wheelwright is a craftsman who builds or repairs wooden wheels. The word is the combination of "wheel" and the word "wright" as in shipwright and arkwright. This occupational name became the English surname Wright. It also appears in surnames like Cartwright and Wainwright. It corresponds with skilful metal workers being called Smith.

This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water. Some remain current, while many date from the 17th to 19th centuries. The word nautical derives from the Latin nauticus, from Greek nautikos, from nautēs: "sailor", from naus: "ship".

A helmsman or helm is a person who 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 fishing vessels and yachts, the functions of the helmsman are combined with that of the skipper; on larger vessels, there is a separate officer of the watch who is responsible for the safe navigation of the ship and gives orders to the helmsman, who physically steers the ship in accordance with those orders.

The rim is the "outer edge of a wheel, holding the tire". It makes up the outer circular design of the wheel on which the inside edge of the tire is mounted on vehicles such as automobiles. For example, on a bicycle wheel the rim is a large hoop attached to the outer ends of the spokes of the wheel that holds the tire and tube. In cross-section, the rim is deep in the center and shallow at the outer edges, thus forming a "U" shape that supports the bead of the tire casing.

The artillery wheel was a nineteenth-century and early-twentieth-century style of wagon, gun carriage, and automobile wheel. Rather than having its spokes mortised into a wooden nave (hub), it has them fitted together in a keystone fashion with miter joints, bolted into a two-piece metal nave. Its tyre is shrunk onto the rim in the usual way, but it may also be bolted on for security.

Self-steering gear is equipment used on sail boats to maintain a chosen course or point of sail without constant human action.

Weather helm is the tendency of sailing vessels to turn towards the source of wind, creating an unbalanced helm that requires pulling the tiller to windward in order to counteract the effect.

Relieving tackle is tackle employing one or more lines attached to a vessel's steering mechanism, to assist or substitute for the whipstaff or ship's wheel in steering the craft. This enabled the helmsman to maintain control in heavy weather, when the rudder is under more stress and requires greater effort to handle, and also to steer the vessel were the helm damaged or destroyed.

<span class="mw-page-title-main">Whipstaff</span> Sailing ship steering device

A whipstaff is a steering device that was used on European sailing ships from the 14th to the 17th century. Its development preceded the invention of the more complex ship's wheel and followed the simple use of a tiller to control the steering of a ship underway.

This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water. Some remain current, while many date from the 17th to 19th centuries. The word nautical derives from the Latin nauticus, from Greek nautikos, from nautēs: "sailor", from naus: "ship".

References

↑ "helm n²" . Oxford English Dictionary (Online ed.). Oxford University Press.(Subscription or participating institution membership required.)
↑ "Ship Steering Wheel History". Articlesfactory.com. 2010-11-23. Retrieved 2018-06-20.
1 2 zu Mondfeld, Wolfram (2007) [1977]. Historic Ship Models. New York City: Sterling Publishing Company. ISBN 978-1-4027-2186-1. OCLC 60525064 . Retrieved 3 September 2013.

External links

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[1] "helm n²" . Oxford English Dictionary (Online ed.). Oxford University Press.(Subscription or participating institution membership required.)

[2] "Ship Steering Wheel History". Articlesfactory.com. 2010-11-23. Retrieved 2018-06-20.

[wolfram-3] 1 2 zu Mondfeld, Wolfram (2007) [1977]. Historic Ship Models. New York City: Sterling Publishing Company. ISBN 978-1-4027-2186-1. OCLC 60525064 . Retrieved 3 September 2013.

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