Oar
Overview
 
An oar is an implement used for water-borne propulsion
Marine propulsion
Marine propulsion is the mechanism or system used to generate thrust to move a ship or boat across water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting a motor or engine turning a propeller, or less frequently, in jet...

. Oars have a flat blade
Blade (disambiguation)
A blade is a sharp cutting part, for instance of a weapon or tool.Blade may also refer to:* Bladed weapon, especially a sword* Razor blade, used for shaving* Blade , a type of stone tool...

 at one end. Oarsmen grasp the oar at the other end. The difference between oars and paddles are that paddles are held by the paddler, and are not connected with the vessel. Oars generally are connected to the vessel by means of rowlock
Rowlock
A rowlock or oarlock is a brace that attaches an oar to a boat. When a boat is rowed, the rowlock acts as a fulcrum, and, in doing so, the propulsive force that the rower exerts on the water with the oar is transferred to the boat by the thrust force exerted on the rowlock.On ordinary rowing...

s or tholes which transmit the applied force to the boat. In this system (known as a second class lever) the water is the fulcrum
Lever
In physics, a lever is a rigid object that is used with an appropriate fulcrum or pivot point to either multiply the mechanical force that can be applied to another object or resistance force , or multiply the distance and speed at which the opposite end of the rigid object travels.This leverage...

.

Oarsmen generally face the stern
Stern
The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...

 of the vessel, reach as far as they can towards the stern, and insert the blade of their oar in the water.
Encyclopedia
An oar is an implement used for water-borne propulsion
Marine propulsion
Marine propulsion is the mechanism or system used to generate thrust to move a ship or boat across water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting a motor or engine turning a propeller, or less frequently, in jet...

. Oars have a flat blade
Blade (disambiguation)
A blade is a sharp cutting part, for instance of a weapon or tool.Blade may also refer to:* Bladed weapon, especially a sword* Razor blade, used for shaving* Blade , a type of stone tool...

 at one end. Oarsmen grasp the oar at the other end. The difference between oars and paddles are that paddles are held by the paddler, and are not connected with the vessel. Oars generally are connected to the vessel by means of rowlock
Rowlock
A rowlock or oarlock is a brace that attaches an oar to a boat. When a boat is rowed, the rowlock acts as a fulcrum, and, in doing so, the propulsive force that the rower exerts on the water with the oar is transferred to the boat by the thrust force exerted on the rowlock.On ordinary rowing...

s or tholes which transmit the applied force to the boat. In this system (known as a second class lever) the water is the fulcrum
Lever
In physics, a lever is a rigid object that is used with an appropriate fulcrum or pivot point to either multiply the mechanical force that can be applied to another object or resistance force , or multiply the distance and speed at which the opposite end of the rigid object travels.This leverage...

.

Oarsmen generally face the stern
Stern
The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...

 of the vessel, reach as far as they can towards the stern, and insert the blade of their oar in the water. As they lean back, towards the vessel's bow
Bow (ship)
The bow is a nautical term that refers to the forward part of the hull of a ship or boat, the point that is most forward when the vessel is underway. Both of the adjectives fore and forward mean towards the bow...

, the blade of their oars sweeps the water towards the stern, providing forward thrust
Thrust
Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a force of equal magnitude but opposite direction on that system....

 - see lever
Lever
In physics, a lever is a rigid object that is used with an appropriate fulcrum or pivot point to either multiply the mechanical force that can be applied to another object or resistance force , or multiply the distance and speed at which the opposite end of the rigid object travels.This leverage...

.

For thousands of years vessels were powered either by sail
Sail
A sail is any type of surface intended to move a vessel, vehicle or rotor by being placed in a wind—in essence a propulsion wing. Sails are used in sailing.-History of sails:...

s, or the mechanical work of oarsmen, or paddlers. Some ancient vessels were propelled by either oars or sail, depending on the speed and direction of the wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

 (see galley).

Construction

Oars have traditionally been made of wood. The form is a long shaft (or loom) with a flat blade on the end. Where the oar connects to the boat there is a "collar" which stops the oar slipping past the rowlock. Oars usually have a handle, which may be a material sleeve or alternatively a shape carved to fit the hands.

Oars used for transportation

The oars used for transportation come in a variety of sizes. The oars used in small dinghies
Dinghy
A dinghy is a type of small boat, often carried or towed for use as a ship's boat by a larger vessel. It is a loanword from either Bengali or Urdu. The term can also refer to small racing yachts or recreational open sailing boats. Utility dinghies are usually rowboats or have an outboard motor,...

 or rafts can be less than 2 metres long. In classical times warship
Warship
A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way from merchant ships. As well as being armed, warships are designed to withstand damage and are usually faster and more maneuvrable than merchant ships...

s were propelled by very long oars that might have several oarsmen per oar. These oars could be more than a dozen
Dozen
A dozen is a grouping of approximately twelve. The dozen may be one of the earliest primitive groupings, perhaps because there are approximately a dozen cycles of the moon or months in a cycle of the sun or year...

 metres long.

Oars used for competitive rowing

The oars used in competitive rowing are long (250–300 cm) poles with one flat end about 50 cm long and 25 cm wide, called the blade. The part of the oar the oarsman holds while rowing is called the handle. While rowing, the oars are supported by metal frames attached to the side of the boat called outrigger
Outrigger
An outrigger is a part of a boat's rigging which is rigid and extends beyond the side or gunwale of a boat.In an outrigger canoe and in sailboats such as the proa, an outrigger is a thin, long, solid, hull used to stabilise an inherently unstable main hull. The outrigger is positioned rigidly and...

s. Classic oars were made of wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

, but modern oars are made from synthetic material, the most common being carbon fibre.

Oars used as trophies

The sport of competitive rowing has developed a peculiar tradition of using an oar as a memento of significant race wins. A 'trophy oar' is not presented at the end of the race as a more familiar precious metal cup might be, but rather given by the club, school or university that the winning crew or rower represented.

A trophy oar is a competition oar that has been painted in the club colours and has then had the details of the race signwritten on the face of the blade. The most common format would have the coat of arms or crest of the club or school positioned in the centre, with the crew names and the race details arranged around this.

Many older universities (Oxford
Oxford
The city of Oxford is the county town of Oxfordshire, England. The city, made prominent by its medieval university, has a population of just under 165,000, with 153,900 living within the district boundary. It lies about 50 miles north-west of London. The rivers Cherwell and Thames run through...

 and Cambridge
Cambridge
The city of Cambridge is a university town and the administrative centre of the county of Cambridgeshire, England. It lies in East Anglia about north of London. Cambridge is at the heart of the high-technology centre known as Silicon Fen – a play on Silicon Valley and the fens surrounding the...

 would be prime examples) and their colleges have long histories of using the trophy oar and many examples are on display in club houses around the world.

In culture

The Norwegian municipalities of Fedje
Fedje
Fedje is an island municipality in the county of Hordaland, Norway. Fedje was separated from Austrheim on 1 January 1947.The main island of Fedje is surrounded by about 125 smaller islands and rocks mostly north of the main island, and the name Fedje applies both to the main island, and to all the...

 and Herøy
Herøy, Nordland
Herøy is a municipality in Nordland county, Norway. It is part of the Helgeland traditional region. The administrative centre of the municipality is the village of Herøy. Herøy was separated from Alstahaug in 1862...

 have oars in their coat-of-arms.

Oars have been used to describe various animals with characteristics that closely resemble the said rowing implement. The members of the Family Regalecidae, elongated deep-sea fishes, are called oarfish
Oarfish
Oarfish are large, greatly elongated, pelagic Lampriform fishes comprising the small family Regalecidae. Found in all temperate to tropical oceans yet rarely seen, the oarfish family contains four species in two genera...

 because their body shape is similar to that of an oar. The hawksbill turtle
Hawksbill turtle
The hawksbill sea turtle is a critically endangered sea turtle belonging to the family Cheloniidae. It is the only extant species in its genus. The species has a worldwide distribution, with Atlantic and Pacific subspecies. E. imbricata imbricata is the Atlantic subspecies, while E...

's genus of Eretmochelys is derived from the Latin root eretmo, which roughly translates to oar. The turtle was so-named because of the oar-like shape of its front flippers.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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