Tractor pulling
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.
While it is said that the term horsepower is derived from this event, the concept was developed earlier, in experiments and measurements performed by James Watt and Mason Worrell.
It wasn't until 1929 that motorized vehicles were put to use in the first events at Bowling Green, Missouri, and Vaughansville, Ohio.
The NTPA's early years were events that used standard farm vehicles, with the motto "Pull on Sunday, plow on Monday".
Tractors remained single-engined until two Ohio brothers, Carl and Paul Bosse, introduced the crossbox, which could allow multiple engines to be attached to a single driveshaft.
Soon tractors became single-use machines that were not used on the farm, making the "Pull on Sunday, plow on Monday" motto obsolete.
[citation needed] The growing popularity of the sport caused the creation of a new four-wheel–drive division in 1976, which captured a large fan base.
Today the four-wheel–drive division is one of the most popular with the success of trucks like the Holman Brothers "4-Play" Chevy and Bob Boden's "Studley Studebaker".
The division imposes a weight limit of 2,800 kilograms (6,200 lb) on each competing truck, a maximum width of 2.4 meters (8 ft), and a maximum distance of 4.6 meters (15 ft) from the centerline of the rear axle to the front of the vehicle (including weight racks and tow hook).
[citation needed] The National Tractor Pullers Association restricts engines to 9,420 cm3 (575 cu in) and two valves per cylinder.
[2] Super Stock tractor Open class uses primarily methanol fuel (some are diesel versions).
The Super Stock Open machines can generate over 4,400 kilowatts (6,000 PS) and 5,400 newton-meters (4,000 lbf⋅ft) of torque, with billet or re-cast engine blocks.
The Diesel super stock tractors generate close to 3,700 kilowatts (5,000 PS) and 8,100 newton-metres (6,000 lbf⋅ft) of torque and are allowed to compete in the Open class, which very rarely occurs anymore.
The light overall weight makes this a driver's class as significant skill is required to keep the tractor on the track.
The mini-modified class is a highly specialized and custom built tractor to be fitted with a naturally aspirated engine, at minimum.
Whereas, their larger counterparts, the Modifieds, will weigh 2,700, 3,400 and 3,600 kilograms (6,000, 7,500 and 8,000 lb), utilizing the same engine that a Mini has, but, with multiple powerplants per custom built tractor chassis.
[1] People who were event organizers at Bowling Green, Missouri and Vaughansville, Ohio found out farmers were doing this and that it drew spectators.
Some pulling competitions will have a ‘dyno’, connecting the PTO shaft on the tractor to a dynamometer to test the horsepower.
[4] The drawbar on a tractor should be no shorter than 18 inches (460 mm) from the center of the rear axle to the point of the hitch.
It has developed over the years into a highly competitive and technical sport, where the difference between first and last place may be as small as one or two metres.
This is often a local school, sporting, service or community club (for example; Apex, Rotary, Lions, Netball, Cricket, Football) who use the event as a fundraiser.
In the west the Western Australian Tractor Pullers Association (WATPA) runs events and is affiliated with the ATPA.
Competition is open to both women and men, the only restriction being that competitors must at least hold a current Learner Driver’s Permit.
The Junior Modified Pulling Association conducts an "introductory" class for 8- to 16-year-olds to develop driving, mechanical and competitive skills.
