Most people know of the Tyrell Racing 'Project 34' six-wheeled F1 car but few are aware that more than one famous F1 constructor experimented with the six-wheel F1 concept. The March Engineering company of Bicester, UK did just this in the lates 1970s.
The Tyrell P34: four wheels at the front
The front wheels of an open-wheeled F1 car generate aerodynamic drag. The thinking behind the Tyrell car was that this drag affect could be reduced by using smaller tyres at the front. To counteract the corresponding loss of front-end grip, Tyrell built a car with four tiny front wheels thereby overcoming the drag effect and actually increasing grip. File:Tyrell 6 wheels.jpg
The P34 was reasonably successful with the two cars taking a memorable 1-2 in the Swedish Grand Prix in 1976. The Tyrell team also finished 3rd and 4th overall in the championship. The car was less successful in 1977 however and the idea was dropped. Although Goodyear had manufactured special 10" tyres for the car, it had failed to match the development work on them compared to the normal sized tyres used by other teams. With all four front wheels steering the car, Tyrell also found that the P34's complicated four-wheel front suspension assembly added a lot of weight to the car.
The 2-4-0 concept: four wheels at the rear
At March Cars in Bicester, designer Robin Herd had watched the P34 closely and, by late 1976, had come to the conclusion that the "four front wheels" concept was something of a blind alley. In his assessment, the improved aerodynamics at the front were largely negated by the rear tyres which account for 30-40% of the car's total drag. He also felt that the extra grip they generated would be more useful at the rear end.
With this in mind, Herd drew up plans for a six-wheeled car with four driven wheels at the rear. His theory was that with all six tyres the same size as a regular F1 front tyre, the car would not only be be slimmer than normal F1 cars but would possess improved aerodynamic performance at the rear with much cleaner air passing over wing. Four driven wheels would also mean better traction and, unlike the Tyrell, there would be no problem with tyre development since the car would use exactly the same rubber as other Goodyear-shod competitors.
Design, construction & development of the March 2-4-0
With the apparent technical advantages of this concept laid out, Max Mosely (Herd's partner at March Cars) pressed for a prototype to be built. Max was more business-minded than Robin and had already noted that the P34 had been a tremendous publicity coup for Tyrell. Aside from the technical merits, he believed a March six-wheeler would be an irresistible package to present to potential sponsors.
The car was designated as the March 2-4-0 following the practice used to describe railway rolling stock: Two wheel steering, Four wheel drive, Zero differential.
Unfortunately, the March team was at something of a low point financially during 1976/77 and developing an all-new six-wheel car would have been too expensive. As a compromise measure, a 1976-design Cosworth DFV-powered March 761 was adapted by team engineer Wayne Eckersley in a quiet corner of the Bicester factory. Existing parts from the factory stores were used wherever possible.
But this wasn't the only compromise. A key feature of a car with four driven wheels at the rear would be an ingeniously-designed and very strong gearbox. Ingenuiety was required to minimise any frictional power losses. Increased strength would be needed to counteract the higher torsional and flexural stresses that the close-coupled four-wheel-drive system would generate.
Herd's original design for the gearbox casing recognised this and specified a series of heavy strengthening ribs to counteract the additional loading. But at some point in development, after costing the design, it was decided that the casting would be too complex and expensive to produce as it was. By way of a cost-cutting measure, some of the ribs were duly removed from the drawing.
In fact, the design used a standard Hewland gearbox for the first axle. To this, the new casing, gears and an extended pinion for the second axle were fitted. Practically, this meant that any 761 chassis could be easily adapted should the concept prove workable.
Once the 2-4-0 was partially built, the press were invited to the factory in early December 1976 for a viewing of the hitherto "secret" project. In truth, the striking flat-white chassis Herd presented to the press was little more than a full-scale mock-up but it generated a huge amount of excitement - making the cover of that week's Autosport. On top of this, the assembled journalists were promised a full running demonstration at Silverstone scheduled for a fortnight later.
Testing the 2-4-0
All hands at Murdoch Road were now duly pressed into service and a proper running car was made ready on time. Unfortunately, the inevitable happened. Within half a lap the gearbox casing flexed and the gears became unmeshed. There was no time to make a new stronger casting and so the rear crown wheel and pinion were quietly removed. Effectively it had become a two-wheel drive car again. Fortunately for March, it was a wet day at the circuit and the driver (Howden Ganley) could not push the car too fast and the test was deemed a success by the assembled media.
Whatever the press wrote, there was no escaping the fact that the car needed the new gearbox casing and a serious development program. Unable to afford the time and resources that this would require, the 2-4-0 project was put on the "back-burner".
The car was eventually fitted with a stronger gearbox and ran at Silverstone in February 1977 with Ian Schekter at the wheel. Although it was another wet day, the car was run up and down the Hangar Straight and, with four driven wheels, Scheckter reported that the traction was incredible. More importantly from Mosely's perspective, the car - in it's new blue & white Rothmans livery (March's main sponsor at the time) - again made Autosport magazine's front page. The car also appeared briefly in practice at the 1977 Brazilian GP although it did not race. But this was the end of 2-4-0's Grand Prix racing history. When it reappeared at the Belgium GP in June, the 761 chassis had been re-converted back to four wheels.
2-4-0 in hillclimbing
In 1979 the 2-4-0 concept was revived by British Hillclimb specialist Roy Lane. Lane had bought a 771 chassis and with Robin Herd's blessing was loaned the 2-4-0 transmission unit. The fact that the 2-4-0 was originally an inexpensive workshop conversion of the standard March F1 chassis meant that Lane was easily able to fit the unit to his car. Taking advantage of that incredible six-wheel traction, Lane won several British hill-climbing events in the 771/2-4-0 that year.
The legacy of the 2-4-0 project
The 2-4-0 concept may not have been without merit. It is possible that if a weight-shedding program had been pursued (perhaps using using high-tech materials) and the car's suspect handling improved, the 2-4-0 could have been a major success story. The concept would certainly have adapted well to "ground-effect" which was the coming technology in F1.
The William F1 team seem to have agreed because they subsequently built a "2-4-0" style six-wheeler (designated FW08B) in 1982. However, any hope of seeing a "2-4-0" race car compete in a grand prix was finally consigned to history when the FIA banned four-wheel drive. The FW08B remains in William's museum.
The March 2-4-0 story was not without a silver lining for the company that built it. As Max Moseley had surmised, the car was a huge publicity magnet for the company. In actual fact, it is cited as the most profitable car they ever built because Scalextric bought the rights and produced a hugely popular 1/32 scale slot-racing replica.