Running Replica of International’s Turbine Tractor Concept Headed to Auction

It's streamlined like a '60s jet because it's also powered by one.
International Harvester's one-off turbine-powered tractor

The United States’ postwar enthrallment with jet engines infected everyone—even International Harvester, which built an experimental turbine tractor named the HT-340. But while the original example was almost destroyed over 60 years ago, this obscure piece of history is alive and kicking again. And now, it’s coming up for sale.

The HT-340, according to Farm Collector, was designed by International to combine promising new technologies of the day, such as hydrostatic drive and turbine engines. International had already developed hydrostatic transmissions in the 1950s, so all it had to do was attach one to a turbine from its aerospace subsidiary, the Solar Aircraft Company. The resulting vehicle was meant to hit the show circuit but was seriously damaged in July 1961, when the truck carrying it left the road after a bird flew into its cab. Its remains were rehashed into a new turbine concept, the HT-341, which was later donated to the Smithsonian, leaving the 340 an almost-forgotten ghost.

But it wasn’t forgotten, as it made an impression on former GM machine repairman Brian Harris. He set about recreating the HT-340 on the basis of a regular 340, apparently using original HT-340 blueprints, and a Solar T-62 Titan APU. (That’d be an auxiliary power unit: a type of small turbine often used as generators in aircraft, and occasionally in cars too.)

Harris had to design his own reduction gearbox, so as to bring transmission input shaft speeds down below 2,000 rpm. He also had to design a different brake system, and use photos of the HT-341—outwardly just a recoloring of the HT-340—to recreate its body. Test drive day eventually came though, and the reborn HT-340 astounded Harris.

“What surprised me the most was how far ahead International was in their thinking and their design,” Harris told Farm Collector. “The HT-340 was built as a concept tractor, not a production tractor. But look how close they were to modern-day tractors. It could have been designed last year. They were right on with the look, but way off with the mechanics. At that time, people thought the turbine was the wave of the future, but it wasn’t.”

Indeed it wasn’t; turbines are extremely loud, especially at close range, and often thirsty. The HT-340 Harris built, for example, was reported to drink a gallon of aviation fuel every five minutes. But even such extreme fuel consumption is secondary to the fact that a running turbine tractor exists, and that it’s coming up for sale this November at Mecum‘s farm equipment auction. It’s definitely not of much use on a farm, but it might be competitive in tractor racing. Fail that, it’d at least be one hell of a parade piece.

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