Saturday, 6 February 2016

Talking Turbines - The Lotus 56B

Emerson Fittipaldi at Monza 1971

'Pratt and Whitney', two names synonomous with the world of aviation for producing engines. Yet in 1971 the cutting edge Lotus team married a such an engine to a Formula 1 car. The result was the gas turbined Lotus  56B, a radical approach to speed whose journey and development proved bitter sweet.

The 1949/50 'Rover Jet 1
If your unsure what a gas turbine is your probably not alone. Quite simply its an engine which uses the rush of high speed hot burning 'gas' to spin a turbine. The jet engine on a commercial airliner is a form of gas turbine. However rather than propelling itself with fast exiting gas known as 'thrust', a spinning turbine can rotate a shaft for drive. In this form your will find these packing a punch in helicopters and turbo prop aircraft. Some saw the potential of these relatively compact, lightweight and powerful engines to power a road car.

Rover had been experimenting with gas turbined cars, producing 'JET1' in 1949. After further development and prototypes they paired up with BRM to enter the Le Mans 24 hours in '63 and '65. A best place of 8th showed some promise and potential.

1965 Rover-BRM Le Mans entry

Across the pond American Ken Wallis approached motoring legend Carol Shelby, attempting to drum up interest and backing for a gas turbine racer. His idea was laughed off but he had better luck with Andy Granatelli of the STP oil corporation. With financial backing a car was to be produced for the great Indianapolis 500. The STP-Paxton Turbocar known as 'Silent Sam' would debut the gas turbine at Indianapolis. The metallic rumble of a piston engine was replaced with a jet like 'woosh'. Unusually the Pratt and Whitney ST6 engine was mounted side by side with the driver. It also featured four wheel drive, simplified by the fact the car didn't need a clutch or gearbox. At its debut at at the 1967 Indianapolis 500 the car took a commanding lead. With just eight laps remaining the car retired with a transmission bearing failure. Although not scoring points the car had demonstrated unmatched pace with its relatively compact and powerful power plant. The governing body feared dominance and wanted to reduce the performance advantages. For the following year air restrictor plates were to be fitted to gas tubine entries.

Like Father Like Son: Damon Hill driving his Dad's 59
The 'Silent Sam' with its side by side engine layout

The potential was recognised by Colin Chapman's legendary Team Lotus, a team always pushing the boundaries of engineering technology. Impressed with the British outfit's proven track record the STP oil corporation duly supplied sponsorship money. Andy Granatelli worked alongside Colin Chapman and Lotus designer Maurice Philippe to produce a contender. The same Pratt and Whitney ST6 engines were supplied with some small modifications. With Team Lotus' creative chassis design and resources the result was a much more sophisticated effort than 'Silent Sam'. It featured a low slung nose to give the car an aerodynamic 'wedge' shape. Coupled with the Lotus ethos of keeping overall weight to an absolute minimum the design clawed back the lost ground from the air restrictor plate.

Graham Hill at the 'Brick Yard', aka Indianapolis

Entering the 1968 Indianapolis 500 with four cars the project was to star the phenomenal talent of Jim Clark. The double Formula 1 World Champion had already won the famous race in 1965 and was teamed with the equally successful Graham Hill. Sadly Clark was killed in a Formula 2 race at Hockenheim that year and was replaced by Mike Spence. The tragedy was to be further compounded before the race began. The car proved competitive in practice when Spence set the fastest average speed of 169.55 mph. However when misjudging the entry to the first corner his car smashed into the unforgiving concrete wall. The right front wheel entered the cockpit and left the 31 year old with fatal head injuries. The three remaining cars of Graham Hill, Joe Leonard and Art Pollard entered the race. Pollard was the last team car remaining and with a few laps to go narrowly missed out on victory, retiring from the lead with fuel pump failure. The 'Silent Sam' STP-Paxton entry had missed the grid after a previous crash in qualifying. It seemed only a matter of time before a gas turbine powered car was going to take victory at Indy. Unfortunately a new raft of rules from the governing body would make this form of propulsion uncompetitive.

Fittipaldi in the 56B
Colin Chapman had intended the 56 to also compete in Formula One, and Lotus developed the modified 56B. The gas turbine produced approximately 600hp, which was around 175 hp more than its piston engined rivals. Once the turbine reached optimal rotation the acceleration was unmatched. Furthermore no gearbox was required or a bulky cooling system. The engine had less moving parts which made it potentially more reliable. Four wheel drive grip made the car superior in wet weather. However there were significant disadvantages. Primarily the gas turbine was very thirsty, with the stop start nature of a Grand Prix racing requiring extra fuel capacity. Heavy tanks stored 280 litres in the sidepods. The gas turbine engine also suffered from hugely unresponsive lag. Forget your primitive turbo cars of the 80's, here waiting three seconds for the power after hitting the throttle was quite normal. Engine braking was non existent and the throttle was also unresponsive when backing off, pushing the car further into the corner. A hefty inboard braking system was required to handle the extra requirements. Suddenly what seemed minor hurdles at Indianapolis were becoming big obstacles to the 1971 Formula One campaign.

The car debuted at the non-championship Race of Champions at Brands Hatch that March. Emerson Fittipaldi qualified 7th but retired with suspension failure. The same problem plagued the car at the next two non-championship meetings, but Fittipaldi managed 3rd place in the final heat. What was becoming apparent was the four wheel drive made the 56B untouchable in wet conditions. However in the dry this system would have produced undesirable understeer making driving this strange car even more of a challenge. According to Fittipaldi it was "very difficult to drive. Very very difficult. We knew we would have to do a lot of development on that car to make it competitive, but it never gave good results."

The Pratt and Whitney ST6 in the back of the 56B, Monza
Dave Walker almost look set to take victory at the Dutch Grand Prix at Zandvoort. Utilising the superior grip of 4 wheel drive in the wet, he carved his way through the field only to spin out. Another retirement followed at the hands of Reine Wisell at the British Grand Prix, this time with mechanical issues. The Lotus 56B's final championship outing at Monza with Emerson Fittipaldi scored a mediocre 8th. At the front Peter Gethin, Ronnie Peterson and Fran├žois Cevert enjoyed the closest finish in Formula 1 history. A lap down Fittipaldi tried desperately to hussle the over weight and understeering 56B towards a good result but the hot weather hindered the performance of the gas turbine engine. The season ended with no wins even though the conventionally powered Lotus 72 was still being used that season. With resources being poured into the gas turbine car the team feared its proven Lotus 72 was becoming neglected. Coupled with Emerson Fittipaldi's lack if patience with the project, the 56B was shelved at the end of the year. The car was entered that year for one last race, an F5000 event at Hockenheim where Fittipaldi placed an impressive 2nd. The following year the Lotus 72 would go on to win the Formula 1 World Championship. The gas turbine wouldn't be pursued in Formula 1 again. This was overshadowed by a certain paranoia that any expensive development road would be pointless if the technology was outlawed. The sole Lotus 56B in existence has been restored and remains under the ownership of Team Lotus [below].

                   "I think this was a blind alley because if we had eventually become successful with it, it would promptly have been banned and then a great deal of money would have been wasted. It happened before at Indy, where the four-wheel drive turbine cars were banned as soon as they started to be successful. Unfortunately the innovator in motor racing is often penalised the moment he produces something of benefit to himself and which makes his cars go faster than those of other competitors. If I could have been sure of at least two year's stability, I would have carried on with developing it, because the turbine is a very good converter of torque. What was wrong with it in Grand is that we ran it with four-wheel drive. If we had built a two-wheel-drive turbine I think that with its smoothness, its very high torque at low rpm and the power it was capable of producing under the formula equivalence, it woukd have been very competitive." -Colin Chapman, Team Lotus

The sole remaining Lotus 56B at Autosport International 2016

1 comment: