The Biggest Tractor in the World (Big Bud 747)

Big Bud 747 Tractor viewed by a crowd
April 22, 2021 Renan 0 Comments

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Big Bud 747 is the world’s largest tractor, a custom-made farm tractor built in the late 1970s in Havre, Montana. The Big Bug 747 is not the only Big Bud tractor built at the manufacturing plant in Montana. The first two tractors were the 250 Series, purchased in 1968 for use on the 35,000 acres at Semenza Farm between Fort Benton and Chester, Montana.

Initially designed by Wilbur Hensler, built by employees at Northern Manufacturing Company, and made for the Rossi Brothers, Big Bud 747 came later in 1977. The Rossi Brothers were Californian cotton farmers who used the large tractor for over a decade before selling it to a farmer in Indialantic, Florida. Both farms used the biggest tractor globally for deep ripping, using the strong tines to loosen hard soil up to 50cm in depth. After falling into disuse, Big Bug 747 headed close to home and found work in Big Sandy, Montana, where it pulled an 80 ft. cultivator that worked 1.3 acres per minute.

By 2009, the decision was made to retire Big Bud 747 from traditional farm work and display the tractor at museums. As Big Bud 747 is a one-of-a-kind tractor, it has become increasingly difficult to find components to match its original design.

With 1100 hp, both owners and exhibitors advertise the Big Bug 747 as the world’s largest farm tractor. In size, it easily dwarfs the size of many of the largest tractors in production today. Depending on parameters, in some areas, the Big Bud 747 approximates twice the size of the biggest tractors on the market today.

Big Bud 747's General Statistics

Taking a look at the Big Bud 747’s general statistics, it’s easy to see why many bill the equipment as the largest ever made. It’s even featured in the Guinness Book of World Records.

  • Height: 14 ft. to the top of the cab.
  • Fender Width: 13 ft. 4 inches over the fenders
  • Dual Width: 25 ft. 6 inches.
  • Frame Length: 27 ft.
  • Frame Length inc. drawbar: 28 ft. 6 inches.
  • Wheelbase: 16 ft. 3 inches.
  • Tire Diameter: 8 ft.
  • Tire Width: 39.6 inches approx.
  • Shipping Weight: 95,000 lbs.
  • Weight (full tank): 100,000 lbs.
  • Ballasted Weight: 135,000 lbs.
  • Diesel Fuel Capacity: 1,000 gallons.
  • Hydraulic Reservoir: 150 gallons.
Big Bud 747 Tractor viewed by a crowd
Myron Reynard, CC BY-SA 2.0, via Wikimedia Commons

Big Bud 747 Modifications

Besides fresh coats of paint, several modifications have been made to Big Bug 747 since it was built in the 1970s. Since the United Tire Company of Canada went bankrupt in 2000, alternative tires had to be sourced for the 747 model. In July 2020, the original 8 ft. tall tires were finally replaced by Goodyear tires, model LSW1400/30r46, which are more than a foot smaller than the originals. The Williams Brothers provided new rims to fit the new tires, which brought the width of the Big Bud tractor to over 25 ft.

Other additions to the Big Bud include modifications to its exhaust stacks and engine power. When it was first built, the tractor’s power output was 760 hp. This was increased to 900 hp by its second owners and further increased to 1100 hp with new injectors fitted by the Williams Brothers in 2011. Since it has finished fieldwork, the farm tractor has been displayed at several museums over the past decade, including Heartland Acres in Independence, Iowa. More recently, it was moved to Clarion, Iowa, where it remains on indefinite loan from the Williams Brothers.

Fast Facts About Big Bud 747

Almost every aspect of the tractor is oversized, with the tire lugs alone having a 20cm height. Over the years, the lugs have been worn down to below 5cm.

It is unknown how many Big Bud tractors exist today, but there was only ever one 747. The name given to it was a nod to Boeing’s 747, the largest aircraft available at the time.

When the largest Big Bud tractor was transferred to Clarion, Iowa, a new exhibition building, known colloquially as the ‘Big Red Shed,’ was built to accommodate it.

When new, the Big Bud 747 tractor cost approximately $300,000. Today, it’s worth is estimated at 3-6 times that value as an exhibition piece.