Lotus 72 Cosworth
The remarkable story of the long-lived legend
WORDS & IMAGES BY: WOUTER MELISSEN
From the late 1950s through the 1960s, the shape of single-seater racing cars changed fundamentally. With the Type 72 Formula 1 car, introduced in 1970, Team Lotus established a general layout that is followed to this day. Like many of the previous Team Lotus Grand Prix cars that broke new ground, the Type 72 was not just innovative, it was also hugely successful.
For many years, single-seater racers in general and Grand Prix cars in particular were “cigar” shaped. The often round nose was open to feed the radiator, which was mounted ahead of the engine and gearbox. Sitting on top of the gearbox was the driver and the fuel and oil were usually stored in the tail of the car. These mechanicals were wrapped tightly in an aluminum body that was either oval or rectangularly shaped.
This general design was first defined during the second half of the 1930s with the Mercedes-Benz W154 and Alfa Romeo 12C 37 as great examples. A reshuffling of the major components of the car is what kickstarted the change in the general layout. A first baby step was to relocate the gearbox to the rear axle in order to improve the weight balance. More consequential was the budding success of the mid-engined Coopers during the second half of the 1950s. Switching the positions of the driver and engine was not an entirely new thing as Auto Union had had success during the 1930s with a mid-engined car. With Coopers winning Grands Prix ever more regularly, the mid-engine layout really caught on and the last Grand Prix to be won by a front-engined F1 car was the 1960 Italian Grand Prix at Monza.
During the next couple of years, it was Team Lotus that was behind the next, more subtle changes. The first truly revolutionary F1 car to emerge from the Hethel works was the Type 25 of 1962. Instead of the tried and trusted tubular spaceframe, it used a monocoque. Like an airplane’s fuselage, this used the aluminum skin that connected the three bulkheads as a load-bearing structure. Five years later, Colin Chapman’s team at was the forefront again with the Type 49. The aluminum moncoque ended at the bulkhead behind the driver’s back, where the Ford Cosworth DFV engine was bolted on. Together with the gearbox, this compact V8 was strong enough to form the final third of the car and to support the rear suspension.
Through all this, the one major component that had not moved was the radiator. That meant that the basic cigar shape was still retained, albeit significantly slimmer, so “cigarillo” would be more appropriate. With the gas turbine-engined Type 56 of 1968, Lotus had already produced a single seater that did not have a front-mounted radiator, simply because it did not need one at all. Designed for Lotus by Maurice Philippe, it sported a wedge-shape nose, which proved to be very aerodynamically efficient.
When the time came to create an all-new Formula 1 car for the 1970 season, Philippe and Chapman were keen to carry over the Type 56’s nose design. As the Type 72 was to be powered by the altogether more conventional Ford Cosworth DFV engine, it did in fact require radiators. These were relocated to the flanks of the car and mounted in what are now commonly referred to as side-pods. In addition to improving the aerodynamic efficiency, there were additional advantages. The pipes running to and from the radiators, through the cockpit, would no longer be required. Moving the radiators close to the car’s center of gravity also had great handling benefits.
As had been the case with the front-mounted radiators, it was the nose that dictated the overall shape of the Type 72; low and wide. The aluminum monocoque chassis was relatively narrow at the front, where a separate steel subframe was fitted to house the suspension. The reason for this was to allow the brake assemblies to be mounted in-board. Moving the discs and calipers away from the wheel resulted in a reduction of the unsprung weight. This refers to the mass of the suspension and wheels, which affects the handling. With the Type 72, Chapman and Philippe opted to move as much in-board as possible in order to improve road-holding. The front brake discs were connected to the wheels through shafts. This layout was possible only because of the lack of radiators in the nose. Otherwise, cooling the discs would have been nearly impossible.
The front suspension itself consisted of a pair of wishbones on each corner. The top ones doubled as a rocker to which an in-board mounted damper was connected. Longitudinal torsion bar springs were fitted, which were actuated by pull-rods from the top wishbones. The rear suspension also featured lightweight torsion bar springs but with outboard dampers. The brake discs were mounted near the center-line of the car, on either side of the gearbox. The geometry of the front suspension was designed in such a way as to prevent the car from diving during braking. Similarly, the rear had an anti-squad geometry to prevent it from sagging while accelerating.
The narrow nose of the monocoque chassis housed the pedal assembly. The fuel was housed in rubber bags that were placed in the broadest section of the monocoque, behind the front-suspension mounting frames and on either side of the driver. Towards the rear of the monocoque, there was a slight taper to allow for the radiators to be mounted. Bolted directly to the aft bulkhead was the latest version of the Ford Cosworth DFV. The naturally aspirated, 3.0-liter V8 was good for around 440 hp in 1970. It was mated to a Hewland FG five-speed gearbox. The gearbox housing was equipped with two frames to which the rear suspension components, disc brake assemblies, and rear-wing mount were connected.
The wedge-shaped nose-cone of the Type 72 sported an integrated wing on either side to keep the front of the car firmly planted. It also featured two small chimneys to help cool the the brake discs. The extremely low bodywork was interrupted only by the cockpit surround, which served to protect the driver from the elements. The two flank-mounted radiators were no taller than the car’s waistline and were neatly tucked away. Initially, two small snorkels on either side of the roll-over bar fed fresh air to the engine but later on a tall air-box was fitted on top of the V8. Originally mounted on top of the gearbox and later suspended behind the car, the rear wing was an area of continuous development.
Painted in the striking red, white, and gold of sponsor Gold Leaf, the Type 72 was a truly radical departure from the norm. It debuted at the 1970 Spanish Grand Prix, which was the second race of the World Championship. Signed to drive for Team Lotus were Jochen Rindt and John Miles. It was a difficult debut as both drivers struggled to get a feel for the car due to the novel anti-dive and anti-squat geometry. Rindt would start eighth but retired early with ignition issues. Miles did not even qualify for the race. Rindt opted to race the aging Type 49 instead for the next two races, even scoring a victory in the Monaco Grand Prix.
Meanwhile, the Type 72 was reworked, removing the anti-dive and anti-squad geometry that made the drivers feel detached from the car. Rindt returned to the wheel of the revised Type 72 at the Dutch Grand Prix. He started the race on pole position and scored a dominant victory. It was the start of a very successful streak for the Austrian with consecutive victories in the French, British, and German Grands Prix. He also clinched pole position in his home race but was unfortunately forced to retire with engine issues early in the race.
Then disaster struck at the Italian Grand Prix where Rindt crashed fatally during practice. The crash was instigated by a failure of the right-hand front brake shaft. The tragic outcome was the result of the barrier splitting on impact, causing the car to slide under the barriers. A lengthy investigation followed but Chapman was eventually cleared of all blame in 1976. Team Lotus withdrew from the race and also sat out the Canadian Grand Prix. Miles had also quit the the team, so Lotus competed in the final two rounds with Emerson Fittipaldi and Reine Wisell. The Brazilian won at his first outing with the Type 72, the United States Grand Prix where Wisell was third. Remarkably, the five wins Rindt scored were enough for him to be crowned World Champion at the end of the year. To this date, he is the only posthumous champion. Lotus also won the Constructors’ trophy.
Despite having won five Grands Prix during the 1970 season, the Type 72 was rarely competitive in 1971. Fittipaldi managed a second in the Austrian Grand Prix but Team Lotus did not win a single Grand Prix for the first time since 1960. Reskinned with a thinner-gauge aluminum and resplendent in the black and gold colors of John Player Special, the Type 72 was back to winning form in 1972. Fittipaldi won four Grands Prix and finished on the podium a further three times. This was enough for the Brazilian to beat Jackie Stewart to the Drivers’ title. Lotus also scored the second Constructors’ trophy with the Type 72. In 1973, Fittipaldi was joined by Ronnie Peterson and together they won eight of the fifteen Grand Prix. Not surprisingly Lotus was World Champion once again but Stewart beat Fittipaldi and Peterson to the title.
Having raced the Type 72 with great success for four seasons, Chapman finally set about creating a replacement for the 1974 Formula 1 World Championship. Dubbed the Type 76, it featured a longer wheelbase, distinct twin-plane rear wing, and a trick semi-automatic gearbox with an electronically operated clutch. On paper, the Type 76 was yet another groundbreaking Lotus Formula 1 car, but it failed miserably. It debuted in round three of the 1974 season where Lotus drivers Peterson and Jacky Ickx collided early on. It was a sign of things as the Type 76 managed to reach the finish just once in seven outings, with Peterson crossing the line in fourth during the German Grand Prix. The Swede raced the Type 72 in twelve rounds, scoring three wins. For 1975, Lotus even built a ninth Type 72 and campaigned the six-year-old car for a final season before the Type 77 proved a proper replacement in 1976.
With a career spanning six seasons, the Type 72 made a remarkable one hundred forty-nine Grand Prix starts. Of these, twenty were converted into victory with two Drivers’ and three Constructors’ trophies as the resounding result. Undeniably one of the most successful Formula 1 cars of all time, the Type 72 also set in stone the layout of a single-seater racing car, which is still used to this day. Of the nine cars built in period, one was destroyed in Rindt’s fatal crash while another was rebuilt with a new chassis number. Used by Fittipaldi for most of his Type 72 outings, the fifth chassis was also comprehensively damaged in period and rebuilt around a new monocoque. The remains were retained by Lotus and the original chassis “R5” has recently been restored by Classic Team Lotus, so there are currently eight Type 72s in existence.