Oar (sport rowing)

In rowing, oars are used to propel the boat. Oars differ from paddles in that they use a fixed fulcrum, an oarlock attached to the side of the boat, to transfer power from the handle to the blade, rather than using the athlete's shoulders or hands as the pivot-point as in canoeing and kayaking.

When the rower uses one oar on one side, it is called sweep rowing that the single oar is called a "sweep" oar. When the rower uses two oars at the same time, one on each side, it is called sculling, and the two oars are called a pair of "sculls". Typical sculls are around 284 cm - 290 cm in length — sweep oars are 370 cm - 376 cm. A scull has a smaller blade area, as each rower wields a pair of them at any one time, operating each with one hand. Since the 1980s many oars have been adjustable in length.

The shaft of the oar ends with a thin flat surface 40 to 50 cm long and 25 cm wide, variously called the blade or spoon. Further along are the loom (or shaft), 2/3 of the way up which is the sleeve (including a wearplate) and button (or collar), and at the very end the handle. The handle may revert to wooden or, particularly in the case of sculls and some 21st century models of sweep-oar blades have rubber, cellular foam, suede or for example wood veneer grips over glass fiber.

The part of the oar the rower holds while rowing is the which is longer for sweep blades as each is held using both hands, than for sculls which are held with one hand.

There are hundreds of different variations of oars in terms of size and manufacturer specifications. "Macon" or "Cleaver" blade shapes of carbon-fibre are the most common in modern-day rowing. Classic oars were made out of wood. Since the use of such synthetic materials, first mass-produced by Dreissigacker in 1975, the weight of an oar has come down from over 7 kg to less than 2.5 kg and 1.275-1.8 kg in the case of sculls. While rowing in the most common competitive boats, fine boats (racing shells), oars are since the early part of the 20th century supported by metal or fibreglass frames attached to the side of the boat called riggers for extra leverage.

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Wikipedia