Oar (sport rowing)
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In rowing, oars are used to propel the boat. Oars differ from paddles in that they use a fixed fulcrum 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.
An oar is often referred to as a "blade" in the case of sweep oar rowing and as a "scull" in the case of sculling. Typical sculling oars are around 284 cm - 290 cm in length, while rowing oars are 370 cm - 376 cm long. The shaft of the oar ends with one flat end about 50 cm long and 25 cm wide, called the blade. A sculling oar is shorter and has a smaller blade area than the equivalent sweep oar.
The parts of an oar are (labelled from outside the boat first): spoon, loom (or shaft), 2/3 of the way up is the sleeve (including a wearplate) and button (or collar), and at the very end the handle and grip.
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, but since the use of synthetic materials the weight of an oar has come down from over 7 kg to less than 2.5 kg.
The most common shape seen is the "cleaver" (also called "hatchet"), which is used almost universally. Cleaver blades are asymmetrical, with a somewhat rectangular shape resembling a meat cleaver, hence the name. The shaft of a cleaver blade connects to the blade offset to the top corner of the blade. The shape of the face and the offset connection is designed to maximize the surface area of the blade in contact with the water during the rowing stroke, while also minimizing the amount and depth of the shaft that is submerged and contributing to drag. As the cleaver blade is asymmetrical it may only be used on one side of the boat or the other.
Some clubs use the older "macon" style blades (also called "spoons" or "tulips" or "shovels") for novice crews, usually to develop the basic technique of the rower without the extra complexity of a cleaver blade. A minority of coaches favor macons, but it has been generally accepted since their introduction in 1992 that cleavers give a speed advantage over macons under most conditions.
Macon blades are symmetrical, with an elliptical shape and a ridgeline running down the center of the blade face. The blade is squared off at the end. Despite the blade being symmetrical, modern asymmetrical collars or aesthetic issues regarding decorative paint on the blade face may dictate which side of the boat the blade can be rowed on.
Macon blades achieved prominence at the 1959 European Championship in Mâcon when they were used by the West German national team. West Germany won all the male sweep events that year, except the coxless four.
Prior to the development of the macon blade a longer, thinner shape was used, known as "square" blades or "standard" blades. They are still occasionally used in training for technique.
The development from standard to cleaver, via the macon, is therefore a progression from long, thin blades to shorter, wider ones. In each case there has been a reduction in the area of the blade that actually moves the wrong way through the water: in practice a point of the blade remains stationary relative to the water, with the portion outboard of that point providing drive, and the area inboard of it providing drag. Shorter, wider blades place this pivot point closer to the blade's neck, reducing the area dragging in the water.