The

Chevrolet Chevrolet ( ), colloquially referred to as Chevy and formally the Chevrolet Motor Division of General Motors Company, is an American automobile division of the American manufacturer General Motors (GM). Louis Chevrolet (1878–1941) and ous ...

Turbo Titan III was a

gas turbine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directi ...

-powered concept

cabover Cab-over, also known as cab over engine (COE), cab forward (U.S.), flat nose (Canada), or forward control (UK), is a body style of truck, bus, or van that has a vertical front, "flat face" or a semi-hood, with the cab of the truck sitting abo ...

heavy

truck A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...

designed and built as a working prototype by

General Motors The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...

in 1965. It was accompanied by a matching custom trailer built in stainless steel; the Turbo Titan III was first shown to the public at the 1965 session of the

1964 New York World's Fair The 1964–1965 New York World's Fair was a world's fair that held over 140 pavilions and 110 restaurants, representing 80 nations (hosted by 37), 24 US states, and over 45 corporations with the goal and the final result of building exhibits or ...

History

GM designed and built prototype trucks in the 1950s using the same gas turbine engines as the ones used in its

Firebird Firebird and fire bird may refer to: Mythical birds * Phoenix (mythology), sacred firebird found in the mythologies of many cultures * Bennu, Egyptian firebird * Huma bird, Persian firebird * Firebird (Slavic folklore) Bird species ''Various sp ...

concept sports cars, including the Turbo Titan I (GT-304 turbine, also fitted to Firebird II) and II (GT-305, Firebird III). Rival

Ford Ford commonly refers to: * Ford Motor Company, an automobile manufacturer founded by Henry Ford * Ford (crossing), a shallow crossing on a river Ford may also refer to: Ford Motor Company * Henry Ford, founder of the Ford Motor Company * Ford F ...

had built a similar turbine-powered Big Red concept truck, first shown at the

. The dual-turbine GM Bison was also exhibited at the 1964 World's Fair; under most operating conditions, the Bison would drive on its GT-309 turbine engine, using the auxiliary turbine as needed for loads, grades, or acceleration. Reportedly, the Turbo Titan III prototype was destroyed in the late 1960s.

Design

The Turbo Titan III was built around the General Motors ''GT-309''

engine and featured streamlined

Space Age The Space Age is a period encompassing the activities related to the Space Race, space exploration, space technology, and the cultural developments influenced by these events, beginning with the Sputnik_1#Launch_and_mission, launch of Sputnik 1 ...

-styling.

Styling

The cab was built using fiberglass and steel, with prominent air intakes for the GT-309 engine on either side of the front fascia. At the time, the head of design for General Motors was Bill Mitchell. The chassis was a conventional Chevrolet tilt-cab cab-over-engine, first marketed in 1960. Both the headlight units and front turn signals retracted into the body when not in use. The interior featured aircraft-like gauges and a "twin dial" steering unit.

GT-309 gas turbine

The GT-309 was derived from earlier GM gas turbine engines developed for the Firebird concept cars of the 1950s. For the GT-309, the turbine and compressor were designed to operate at 35,700 RPM, with reduction gearing used for the upper output shaft, generating at a shaft speed of 4,000 RPM. Stall torque was at idle. The GT-309 has a

free-turbine turboshaft A free-turbine turboshaft is a form of turboshaft or turboprop gas turbine engine where the power is extracted from the exhaust stream of a gas turbine by an independent turbine, downstream of the gas turbine. The power turbine is not mechanically ...

design in which the output shaft is not mechanically coupled to the compressor shaft, but to maintain a nearly-constant operating temperature and provide for

engine braking Engine braking occurs when the retarding forces within an engine are used to slow down a motor vehicle, as opposed to using additional external braking mechanisms such as friction brakes or magnetic brakes. The term is often confused with sever ...

, the engine was fitted with a variable clutch that coupled the gasifier (compressor turbine rotor) with the output shaft; this system was developed jointly with

Allison Transmission Allison Transmission is an American manufacturer of commercial duty automatic transmissions and hybrid propulsion systems. Allison products are specified by over 250 vehicle manufacturers and are used in many market sectors including bus, refuse, ...

and branded "Power Transfer". Raw exhaust gas temperature was at the gasifier inlet, but a regenerator was used to muffle noise and recover heat energy by preheating inlet air, resulting in tailpipe exhaust temperatures of . Compared to a diesel engine of similar output, the GT-309 was more compact and was only of the weight. The GT-309 was also fitted to

GM New Look bus The GM New Look bus is a municipal transit bus that was introduced in 1959 by the Truck and Coach Division of General Motors to replace the company's previous coach, retroactively known as the GM "old-look" transit bus. Also commonly known by ...

prototypes, as the Turbo-Cruiser II and III, and other bus prototypes including the RTX and later RTS-3T that competed in the

Transbus Program Transbus was announced in December 1970 as a United States Urban Mass Transportation Administration (UMTA) program to develop improvements to existing transit bus design; at the time, the US bus market was dominated by the GM New Look and Flxibl ...

References

External links