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 has 1100 horsepower. 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.

History
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 designed by Wilbur Hensler and built by Ron Harmon and the employees of his Northern Manufacturing Company, at a cost of $300,000. It was made for the Rossi Brothers, Elmer and Melvin, cotton farmers of Bakersfield or Old River, California. The tractor was used on the 20,000 acre Rossi Brothers farm for eleven years; it was then purchased by Willowbrook Farms of Indialantic, Florida. Both farms used it for deep ripping.

In 1997, after a period of disuse, it was purchased by Robert and Randy Williams, of Big Sandy, Montana, within 60 mi of where it was built. It was used on the Williams Brothers' farm in Chouteau County to pull an 80 ft cultivator, covering 1.3 acre per minute at a speed up to 8 mph.

The United Tire Company of Canada, which made the tractor's custom 8 ft tires, went bankrupt in 2000, partially contributing to the decision to stop using the tractor for regular work in July 2009, and 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.

On July 14, 2020, the Big Bud's original eight-foot tall construction tires were replaced with Goodyear LSW1400/30r46 tires (which are slightly under seven feet tall), with new rims provided by the Williams Brothers to fit them. The new tires brought the width of the Big Bud to just over 25 feet.

The Big Bud 747 returned to the Williams Brothers farm near Big Sandy, Montana, in September 2020, where it worked farm ground once again with an 80-foot wide FRIGGSTAD chisel plow.

General

 * Height: 14 ft to top of cab New tires are about 1 ft shorter than original tires.
 * Length: 27 ft frame; 28 ft to end of drawbar
 * Width: 13 ft over fenders; 25 ft over duals
 * Wheelbase: 16 ft
 * Tires: 8 ft in diameter; 39.6 in in width; (38×35 16 ply duals)
 * Weight: 95000 lb shipping weight; over 100000 lb when 1000 USgal tank is full; 135000 lb fully ballasted

Tank capacities

 * Fuel capacity: 1,000 USgal (diesel fuel)
 * Hydraulic reservoir: 150 USgal tank

Engine

 * Detroit Diesel 16V92T: 16-cylinder, two-cycle engine
 * Power: originally 760 hp, but later increased to 860 hp, then to 960 hp but is now at 1100 hp.
 * Displacement: 1472 cuin, or 92 cuin per cylinder
 * Induction: 2 turbochargers, 2 superchargers
 * Starter: 24 volts; all other electrical is 12 volts
 * Alternator: 75 ampere

Transmission

 * Forward speeds: 6
 * Reverse speeds: 1

Comparison
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. By the 2020s there were several new tractors over 600 hp but still weighing much less, including the 700 hp Fendt 1167 with a low rpm engine and a 2023 Case Quadtrac with over 700 horsepower.

A new Big Bud 700 was built in 2023 with an 18 litre engine and nearly 700 horsepower.