GM’s Bison and Turbo Titan still look futuristic a half-century later

When you mention the word “turbine” in an automotive context, most people likely think of Chrysler’s Turbine Car program, wherein the automaker put 50 jet-powered production prototypes in the hands of regular folks for long-term tests. Likewise, when the topic of the 1964 New York World’s Fair comes up among car enthusiasts, they might discuss how fair attendees could get rides in some of those same Chrysler Turbines, or more typically, how the original Ford Mustang was introduced there to great fanfare. Less well known is another turbine-powered vehicle that debuted at the ’64 exposition, General Motors’ Bison tractor-trailer concept.

Though Chrysler gets most of the attention when it comes to turbine-powered vehicles, all three major American automakers had serious programs dedicated to developing practical road-going jet engines. We’ve covered Ford Motor Company’s massive turbine powered “Big Red” semi, as well as GM’s jet-engined Firebird I, II, and III concepts that three-time Indy 500 winner and GM engineer Mauri Rose test drove (wrecking one of them going for its maximus speed, or so we’ve been told).

In the UK, Rover also experimented with at least one turbine-powered car. As a matter of fact, while it’s Chrysler that is most closely associated with turbines in peoples’ minds, the resources that General Motors put into its multiple turbine programs over the course of six decades likely surpasses what Chrysler applied to the concept. That’s not to diminish the historical significance of the Chrysler Turbine, just placing it in the context of the rest of the industry.

It’s easy to understand the auto industry’s fascination with turbine power. Turbines can run on a wide variety of fuels, from cooking oil to perfumes—just about any burnable liquid or gas. They also have very few moving parts. Besides performance advantages, the fact that turbines have very few moving parts means that they don’t need nearly the maintenance that piston engines need, which is one reason why the aerospace and defense industries embraced them. Also, the early 1960s was an era when the domestic automakers were relatively open to innovation, particularly at General Motors. The period saw the rear-engine, air-cooled Corvair, a turbocharged Oldsmobile, an overhead-cam inline six at Pontiac, and a Tempest with a rear transaxle and “rope-drive.”

In that context, a turbine-powered truck with two engines mounted above the cab doesn’t seem that out of place. One might even argue that while GM’s Bison concept was closer to vaporware than to a functioning truck, it may have been more predictive of the future than those 50 Turbine cars that actually ran, and the program that produced the Bison a year later did indeed introduce an operable turbine truck at the New York World’s Fair.

It’s possible that the real purpose of the Bison turbine truck concept was actually related to the Chrysler Turbine. The Turbine car was introduced about a year before the ’64 World’s Fair opened and with the 50 Italian-built cars getting driven around the country, Chrysler was getting publicity at international, national, and local levels. Much of the contemporary publicity materials on the Bison focused on GM’s fifth generation “GT 309” turbine engine, developed by the automaker’s Allison division. It was rated at 280 horsepower and a whopping 875 lb-ft of torque. Output shaft speed was a maximum of 3600 rpm, stepped down through gearing from turbine shaft speed of 30,480 rpm.

That turbine was a descendant of the GT 302 engine in the Firebird I. By 1964, GM had been working on turbine-powered vehicles for 15 years and perhaps the Bison was America’s largest automaker’s way of saying, “We’ve been working on turbine power too!”

The GT 309 was only one of the Bison’s concept’s engines, though the twin powerplants were more fraternal than identical. The other one might have been more conceptual as few details were given other than a claimed 720 horsepower. The idea behind the double-engine setup was to use the smaller turbine for cruising and low speeds, with the more powerful turbine coming on stream for acceleration, hill climbing, or pulling a second trailer. Actually, one could say that the Bison had three (hypothetical) powerplants, as the concept was intended to have some kind of hybrid electrical system powered by the turbines that provided motive force to both the tractor and the trailer axles.

To find space for the two turbines, GM designers located them in a pod placed above and behind the extreme cab-forward and low-mounted cabin. The driver sits directly in front of the front wheels. The cabin had no doors. Ingress and egress were effected by tilting forward the large glass canopy. The idea was to come up with something that was aerodynamic and allowed a clean flow of air to the turbines.

The entire tractor has a look that is still futuristic today, almost 50 years later. In my research I came across a number of descriptions that compared it to Syd Mead’s artwork. It certainly wouldn’t look out of place in Blade Runner.

The tractor wasn’t the only advanced concept. Years before shipping containers were standardized for intermodal transport, the Bison conceived of an international system of modular, standardized cargo containers that could be automatically stacked end to end on the trailer. The had 8×8-foot cross sections and were said to come in 10, 20, 30 and 40-foot lengths.

Inside the cabin was an aircraft-type yoke with two control handles mounted on a pivoting tower, instead of a steering wheel. Switches between the handles controlled their functions. A seemingly countless number of control buttons and levers were located in the center console, which also had a telephone. Mobile phones then were exceedingly rare. Unlike Ford’s Big Red, which had many of the comforts of home, including a bed, the Bison was pitched as a long-haul truck but had no sleeper compartment.

As mentioned, GM was hyping its latest turbine, the GT 309, which introduced a feature they called Power Transfer, a means of pulling power off of the turbine’s “gasifier” compressor rotor and directing it to the main rotor’s output shaft. In conventional turbines, no power is taken off the compressor. The Power Transfer system was said to improve partial-load fuel economy and acceleration, but the major benefit was a doubling or tripling of engine braking power over a gasoline engine or a diesel engine with a “Jake” brake. A single regenerator on the engine recovered 90 percent plus of the energy from the salvageable exhaust heat, reducing exhaust temperatures to under 500° F. High exhaust heat was a problem that plagued the Firebird concepts. Since the trailer would be sitting directly in the jet exhausts, that could be an issue. No mention, by the way, was made of any “reefer” refrigerated containers.

The Bison had a novel, four-wheel steering system that had four modes. For operating on city streets, just the front axle steered. For tight turns at low speed, the front and back axle steered in opposite directions. Tandem steering, with all four wheels turned in the same direction that could be combined with locking the fifth-wheel trailer mount to turn the Bison into a straight truck. The final mode was the rear axle alone steering, to ease trailer hookups. The Bison also had novel, built-in jacks between the two axles, powered by the air/oil suspension system, which also provided power to sand spreaders for low traction conditions.

The Bison was a non-functioning “pushmobile.” Every period photo is a static shot.

A year after the Bison was introduced, General Motors’ Chevrolet brand, which then also sold heavy trucks along with GM’s GMC brand, debuted a working GT 309-powered truck called the Turbo Titan III. As a matter of fact it worked well enough for GM to have publicized a number of coast to coast runs. Apparently it followed Turbo Titans numbers I and II, but information on those is hard to come by though they were apparently prototypes based on production trucks.  While Turbo Titan III appears to have been based on a conventional truck chassis, the cab and bodywork were all bespoke.

A cabover design, the semi had an electrically-operated tilt cab, with a body fabricated in fiberglass and steel. A pair of fighter jet-looking air scoops in the fascia directed air to the turbine’s intake and also housed pop-out headlamp units. The lines of the modern-looking cab flowed seamlessly into smooth, full skirting that covered the fuel tanks, batteries, and other truck components that are normally exposed, creating a smooth, aero friendly shape.

Inside, the Turbo Titan III had full power accessories and what Chevy called “astronaut seating,” essentially suspended, leather bucket seats with full headrests. A console shifter out of a production Chevrolet shifted the truck’s six-speed automatic transmission, also made by Allison. Like the Bison, the Turbo Titan III had an unusual steering control system, from GM’s Saginaw steering box division, that it branded as the Twin Dial system. Its similarity to Ford’s contemporary Wrist Twist system on a Mercury concept was purely coincidental, perhaps.

As with the Bison, the Turbo Titan III had a custom trailer, a conventional design fabricated in shiny stainless steel.

While turbines are great when it comes to reliability and maintenance, they’re not cheap to build and they’re very thirsty, as in low single-digit mpg. Though it was an innovative age, the promise of turbine-powered road vehicles evaporated almost quicker than some of the more volatile fuels used to run them. A turbine-powered truck has yet to reach production.

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