Tractor pulling
Truck and tractor pulling, also known as power pulling, is a form of a motorsport competition in which antique or modified tractors pull a heavy drag or sled along an 11-meter-wide (35 ft), 100-meter-long (330 ft) track, with the winner being the tractor that pulls the drag the farthest. Tractor pulling is popular in certain areas of the United States, Mexico, Canada, Europe (especially in the United Kingdom, Greece, Switzerland, Sweden, Netherlands, Belgium, Italy, Denmark and Germany), Australia, Brazil, South Africa, Vietnam, India and New Zealand. The sport is known as the world's most powerful motorsport, due to the multi-engined modified tractor pullers.
For the human equivalent, see Vehicle pull.
All tractors in their respective classes pull a set weight in the drag. When a tractor gets to the end of the 100 meter track, this is known as a "full pull". When more than one tractor completes the course, more weight is added to the drag, and those competitors that moved past 91 metres (300 ft) will compete in a pull-off; the winner is the one who can pull the drag the farthest. The drag is known as a weight transfer drag. This means that, as it is pulled down the track, the weight is transferred (linked with gears to the drag’s wheels) from over the rear axles and towards the front of the drag. In front of the rear wheels, instead of front wheels, there is a "pan". This is essentially a metal plate, and as the weight moves toward it, the resistance between the pan and the ground builds. The farther the tractor pulls the drag, the more difficult it gets.
Tractor pulling originated from pre-Industrial Era horse pulling competitions in which farmers would compete with one another to see whose teams of draft horses could pull a heavy load over the longest distance. The first known competitions using motorized tractors were held in 1929 in Missouri and Kentucky. Tractor pulling became popular in rural areas across the Midwestern and Southern United States in the 1950s and 1960s. From there it gradually spread to Canada, Europe, and Australia and New Zealand.
Engines[edit]
Apart from modified standard diesel tractors, a variety[7] of high power engines are used in tractor pulling, which started in the late 1970s. In the early years, mainly single, double or multiple US-made big block dragster engines were used, but nowadays, a lot of parts from discarded military machinery are in use, like Klimov TV3-117 (Isotov)[8] turboshafts from Russian helicopters, Soviet Zvezda M503[9] torpedo boat engines, Continental AV1790[10] tank engines, or World-War-2-era aircraft piston engines in V12-shape (e.g. Rolls-Royce Griffon[11]) or as radial engines (e.g. Curtiss-Wright R-3350[12]). Due to the limited number of vintage warbird engines remaining, some organisations that own them, such as the Fantasy of Flight museum in Florida, refuse to sell engines from their collection to customers that wish to use them for tractor pulling.[13] In recent years a number of agricultural engines have been converted to run on methanol with multi-stage turbocharging.