By Paul Wallem

 Occasionally a new machine looks like the future, but ends up disappearing into the past. The Delorean is one example. The media labeled it the car of the future. It was pictured as the “Time Machine” in the movie “Back to the Future.” Yet production that started in January 1981 lasted only 23 months, ending in December 1982.

The International HT-340 was a different look into the future. Built as a concept tractor in 1960, it was never planned to be a production model. IH coupled a newly developed hydrostatic transmission to a gas turbine engine as a test bench, not only for these two components but to test the use of fiberglass for fender and hood parts. It holds two world records – first gas turbine tractor and first hydrostatic tractor.

Hydrostatic transmissions progressed from that time to become major components on future tractors, combines and more. Thousands came into use.

Gas turbines, however, did not have a future in IH tractors and trucks. International Harvester Co. had purchased Solar Aircraft Co. in 1960 because of its gas turbine developments. The IH Advanced Research Department wanted to look at future possibilities for gas turbines.

What became apparent after more research was the disadvantages of turbine versus diesel: poor fuel efficiency, prohibitive noise level with high-pitched whine, slow torque buildup (57,000 RPM), very large air filter for protection, and reduced traction due to lightweight engine (The engine weighed only 90 pounds).

The tractor was designated HT-340, for hydrostatic turbine. The prototype was badly damaged while being transported after a public showing. According to a retired IH engineer that had worked on the project, it was rebuilt with additional features including a 3-point hitch. The new designation was HT-341.

The concept HT-340 has drawn a great deal of attention through the years. A YouTube video has attracted more than 600,000 viewers.

The tractor was donated to the Smithsonian in 1967. It is now on loan to I & I Tractor & Gas Engine Club, Penfield, Ill. The annual show this year is July 7-10.

The world’s first production tractor with hydrostatic transmission was announced by IH in July 1967. It was in an International 656.

International Harvester was not alone in researching gas turbines for tractors. Various indicate that research also occurred at Deere, Ford, AC and Oliver, as well as several smaller organizations. In a recent forum, a Deere retired service specialist reported that a gas turbine-powered 4230 had been seen during the 1960s. Another retiree stated that Deere experimented with a turbine-driven industrial scraper in the mid-1960s.

Records show a Ford experimental Typhoon model in a 1957 test program. The engine used was a free-piston gas generator-driven turbine that could operate on various fuels. Horsepower rating was 50, and it topped at 45,000 RPM.

Allis Chalmers is said to have experimented with gas turbine power in a dozer tractor. A visitor to the Ford Museum in 1958 claims there was an Oliver on display with a gas turbine engine.

On a smaller scale, several turbine-powered garden tractors can be seen on YouTube at different events. A re-powered Bolens garden tractor with 60 HP can be heard before it is seen.

Another unique gas turbine tractor appeared at the Antique Gas & Steam Engine Museum, Vista, Calif., in 2018. A Cub Cadet (renamed the JetCadet) has a 60 HP turbine under the hood. It uses less space than the conventional Kohler engine and sounds like it will depart the runway any moment.

Jet-powered garden tractors have been included here as an example of the compact size of jet engines. They rarely take up as much space as the convention power units.

There are other tractors with gas turbines, but for special purposes. The German pulling tractor in the attached photo uses four gas turbines and runs away with the boat. Hard to beat this one.

Art Arfons developed the first American jet-powered pulling tractor. In 1979, he won the NTPA national pulling championship. Earlier, in 1962, his jet-powered car at Bonneville Salt Flats set a land speed record of 313.7 MPH with an Allison V1710 aircraft engine. After a serious accident in later years, he gave up on jet-powered cars and turned to jet-pulling tractors.

But not for farming.

Paul Wallem was raised on a dairy farm. He spent 13 years with corporate IH in domestic and foreign assignments. For the next 17 years he owned and operated an IH dealership in Belvidere, Ill., and co-owned a dealership in Plainfield, Wis. He can be reached at pwallem@aol.com.