Saturday, March 7, 2009

An interesting day in automotive history


On March 8th, 1950, British car company Rover unveiled the world's first jet turbine-powered automobile, the Rover JET1.




It had been under development since the end of World War II, during which Rover had participated in the development of early jet engines. Its progress had been a matter of fits and starts, with many difficulties. As one source comments:

The early problems were more financial than technical (to this day JET 1 has a 2nd hand bicycle caliper brake to stop the power turbine turning in neutral), not only were materials horribly expensive but almost unobtainable. In spite of this, the first prototype engine was running by February 1947.

There were of course also technical problems - one has to remember that gas turbines run at over 40,000 rpm and up to that time no one had ever tried (or even thought of) linking this high speed power to drive road wheels. (Rover's solution of using a second power turbine was copied by all who followed later). One should also realise that everyone was learning at the time - it was a miracle if the engine ran at all; test-bed operators were unmarried volunteers!

A typical sequence from a notebook:
  • 1st test: satisfactory light-up, no oil pressure.
  • 2nd test: no light-up.
  • 3rd test: engine exploded.

At the time, Rover saw a great future for the new technology. A contemporary BBC report states:

Car designer Spencer King took the car out for an early spin for the benefit of the television cameras.

He said: "I should like to say first of all this car is very easy indeed to drive. I have driven it quite a bit beforehand and there is no difficulty at all.

"You have two pedals, one to start and one to stop with, and the car handles very nicely. It runs dead straight however fast you're going."

The car runs on petrol, paraffin or diesel oil, but consumption is still high - about five to seven miles a gallon (2km to 2.5km per litre).

Chief Engineer Maurice Wilks says he hopes the car will prove a success. "It is obviously the Rover Company's intention to produce a gas turbine engined car as a marketable proposition if and when that becomes practicable," he said.

"It will certainly be as good as, most probably better than, existing piston engined cars in respect of performance and weight. Probably though, it will not be quite so good in respect of fuel consumption, but to balance that the performance will be superb."


However, these optimistic forecasts were never to be realized, despite ongoing development efforts.

The original JET1 had a rear-mounted jet engine, with its compressor turbine spinning at up to 40,000 revolutions per minute (rpm). In its initial form, this engine developed 100 brake horsepower (bhp), rising to 230 bhp in a redeveloped 1952 version. The compressor turbine drove a second power turbine, which in turn drove the wheels through a reduction gearing system.




The next Rover jet-powered car was the T3, introduced in 1956 (shown below). Its rear-mounted compressor spun at up to 52,000 rpm, developing 110 bhp. The vehicle had four-wheel-drive, a fiberglass body, and four-wheel disc brakes.




This was followed in 1961 by the final passenger car prototype of the turbine vehicle, the T4 (shown below). This preceded the conventional (and very successful) Rover P6 by two years, but used its basic body design.




Unlike its predecessors, the T4 had a front-mounted engine with front wheel drive. It developed 140 bhp, accelerating from 0-60 mph in 8 seconds, and gave fuel economy of 20 miles per Imperial gallon (about 16½ miles per US gallon), compared to the original T1's dismal economy of 6 miles per Imperial gallon (about 5 miles per US gallon).




By now it was clear that jet turbine technology would never be economically competitive with standard internal combustion engines for motor vehicle use (at least, not with the technology of the day), and further development of passenger vehicle prototypes was abandoned. Today, the JET1 prototype is exhibited at the Science Museum in London, England.




The T3 and T4 prototypes are on display at the Heritage Motor Center in the UK.




However, experiments with jet turbines continued in a sports car, the Rover-BRM.






After a couple of years of development, mishaps and learning, the car took part in the 1965 Le Mans 24-hour race, coming 10th overall and 7th in the 'prototype' class. Its average speed was 98.8 mph.




The Rover-BRM is now also on display at the Heritage Motor Center.

Rover blazed the trail for other companies to follow, notably Chrysler in the USA with its Turbine Car of 1963.




Although no jet turbine engine has so far entered commercial production in a passenger or sports vehicle, it has been used with great success to power the world-famous M1 Abrams tank.




Thus, Rover's vision of 1950 has, at least in part, been borne out.

Peter

5 comments:

  1. I believe one ran in an Indy or NASCAR race once but was subsequently banned. Don't remember the details now.

    While in college, Chrysler had a auto tour and brought one of the Turbine cars to campus for a demo. It had a very loud, high-pitched whine. Acceleration was very poor. A '47 GMC pickup could out drag it.

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  2. I can't see turbines competing with the nearly-mature reciprocating piston engine (non-synchronous control of valve motion being the final frontier, I reckon). However, I would be curious to see how possible a turbine car would be in light of modern materials and manufacturing methods. The question is, what to do with all that hot exhaust? It would have to be directed upward to avoid burning other cars, pedestrians, etc.

    Also, the notebook entry is good for a chuckle. Typical English wit, indeed.

    Jim

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  3. Piston engines also need more maintenance. This was the initial reason jets were put on commercial planes, they didn't need to be rebuilt and tuned as often, despite being inefficient even then for flight.

    There's a company that takes old helicopter engines and puts them in pickups and on motorcycles. Leno has one of the bikes. It seems helicopters are a bit stricter on the maintenance, and so when it comes time to rebuild, it's actually cheaper to buy a new engine than have the old one redone.

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  4. I’ve been to the Tanks assembly line in Ohio where they make M1 (and use to make the Striker) and been up-close, standing where they were made, quite impressive. They also gave a live demo. They speed by at 45 or so and slammed on the brakes then turned, ran down a road with big bumps and hills and them flipped on its smoke screen (awesome). Then it came back at around 45 then stopped, did some turret and moving movers. I was surprise at how such a big tonnage moved so fast… and how quite it was!

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  5. Interesting that Jaguar has produced a prototype jet turbine car that solves a lot of the issues.

    Firstly, the turbine is used to charge batteries which in turn drive powerful electric motors.

    The turbines are small and very efficient. In fact the 475bhp car is capable of 200mph and has a range of 560 miles. It runs on petrol, ethanol, methanol, alcohol etc.

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