Big Bud 747
The Big Bud 747 or 16V-747 Big Bud is a large, custom-made farm tractor built in Havre, Montana in 1977. It is billed by the owners and exhibitors as the "World's Largest Farm Tractor". It is about twice the size of many of the largest production tractors in the world, depending on parameter.
The first two Big Bud tractors out of the Havre, Montana plant were the 250-series and were purchased by Leonard M. Semenza of Semenza Farms in 1968 located between Fort Benton, Montana, and Chester, Montana on his 35,000 acre farm. The 747 tractor was originally citation needed] and built by Ron Harmon and employees of his the Northern Manufacturing Company, at a cost of $300,000. It was made for the Rossi Brothers, cotton farmers of Bakersfield or Old River, California, where it was used for 11 years, then it was purchased by Willowbrook Farms of Indialantic, Florida; both farms used it for deep ripping.[
After a period of disuse, it was purchased by Robert and Randy Williams, of Big Sandy, Montana, within 60 miles (97 km) of where it was built, in 1997. It was used on the Williams Brothers' farm in Chouteau County to pull an 80-foot (24 m) cultivator, covering 1.3 acres (0.53 ha) per minute at a speed up to 8 miles per hour (13 km/h).
The United Tire Company of Canada, which made the tractor's custom 8-foot (2.4 m) tires, went bankrupt in 2000, partially contributing to the decision to stop using the tractor for regular work in July 2009, to move the Big Bud 747 to museums.
After its work on the farm, it was displayed at the Heartland Acres Agribition Center in Independence, Iowa. In 2014, the Big Bud 747 was moved to the Heartland Museum in Clarion, Iowa, on indefinite loan from the Williams Brothers; the museum constructed a separate shed for the tractor in 2013.
- Height: 14 feet (4.3 m) to top of cab
- Length: 27 feet (8.2 m) frame; 28 feet 6 inches (8.69 m) to end of drawbar
- Width: 13 feet 4 inches (4.06 m) over fenders; 20 feet 10 inches (6.35 m) over duals[clarification needed]
- Wheelbase: 16 feet 3 inches (4.95 m)
- Tires: 8 feet (2.4 m) in diameter; 39.6 inches (1,010 mm) in width; 
- Weight: 95,000 pounds (48 short tons; 95,000 lb) shipping weight; over 100,000 pounds (50 short tons; 100,000 lb) when 1,000-U.S.-gallon (3,800 l; 830 imp gal) tank is full; 135,000 pounds (68 short tons; 135,000 lb) fully ballasted
- Fuel capacity: 1,000 gallons (diesel fuel)
- Hydraulic reservoir: 150-U.S.-gallon (570 l; 120 imp gal) tank
- Detroit Diesel 16V92T: 16-cylinder, two-cycle engine
- Power: originally 760 horsepower (570 kW), but later increased to 860 horsepower (640 kW), then to 960 horsepower (720 kW) but is now at 1100hp
- Displacement: 1472 cid (24,1 ltr), or 92 cid (1,5 ltr) per cylinder
- Induction: 2 turbochargers, 2 superchargers
- Starter: 24 volts; all other electrical is 12 volts
- Alternator: 75 ampere
For perspective, many of the largest production tractors such as the John Deere 9630 are about half the horsepower, less than half the ballasted weight, and often use a more standard six cylinder class 8 truck engine. Extrapolating historical rules of thumb when tractors were sometimes measured by the size of the mouldboard plough they could pull, Big Bud 747 would be a 50-plough tractor, though this is no longer a practical convention.
- "16-V 747 Big Bud "The World’s Largest Farm Tractor"". Big Sandy, Montana: Williams Big Bud Tractor. Retrieved 2015-06-25.
- "CaseIH Steiger 600". TractorData. Retrieved June 3, 2016.
- McGlothlin, Mike (Mar 1, 2011). "Big Bud: The World's Largest Farm Tractor". Diesel Power (online ed.).
- "Heartland Museum Acquires World's Largest Tractor". The Wright County Monitor (online ed.). Clarion, Iowa. 2014-05-28. Retrieved 2015-06-25.
- "John Deere 9630". TractorData. Retrieved June 2, 2016.
- "Buhler Versatile 575". TractorData. Retrieved June 3, 2016.
- "CaseIH Steiger 620 Quadtrac". TractorData. Retrieved June 3, 2016.
- Williams Big Bud Tractor — official website