The line of Patrick Head- masterminded Formula 1 Williams-Cosworth FW07s proved to be the most effective successors to the Lotus 78-79 series’ legacy of ‘underwing’ ground-effect aerodynamic technology. Patrick had joined Frank Williams in his new Williams Grand Prix Engineering Ltd team on its formation in 1977. He had watched the fast-cornering Lotus 78 with growing interest, but felt he didn’t quite understand its aerodynamic approach. His fledgling team lacked the funds to invest in wind-tunnel test time to learn what he did not know. Consequently his first Williams FW06 design for 1978 made no attempt to emulate Lotus wing-car principles. But with growing Saudia sponsorship, 1979 would be different.

Patrick: “I was aware that Lotus did much of their wind tunnel testing at Imperial College in London, using quarter-scale models. Their tunnel incorporated a moving ground surface beneath the models tested, and I appreciated that was important.”

He contacted Dr John Harvey, head of Imperial’s aeronautics department, “…who explained that Lotus did its work in the tunnel, he did some consultancy work for Arrows, and there was room for one other team. We wanted to be that other team…”

Patrick’s new FW07 design superficially resembled the Lotus 79, “…but I tried to optimise that layout”. He and Neil Oatley completed the design, while new team addition Frank Dernie – ex-Hesketh (and himself an Imperial College graduate) – would contribute greatly to its development.

The Williams FW07 began life as a flat sheet of aluminium honeycomb sandwich material, some 82-inches long and specially bonded with 22-gauge skins sandwiching 0.45-inch thick aviation-spec honeycomb cell filling. Numerous aluminium inserts and dowels fitted into drillings within the sheet as mounting strong points. Two longitudinal slots were routed out, allowing the sheet to be folded along these slots like a child’s cut-out card model to form the basic U-section tub. The necessary brackets were then bonded and riveted into place. The tub was then stiffened by an added tank top behind the cockpit and seat-back panels, plus 20-gauge aluminium inner skins shaped over internal bulkheads along each side. In original 1979 form this cockpit area flexed too much, and for the 1980 FW07B development, folded stiffening fillets were inserted around the driver’s shoulder area.

The front end of the tub supported a rugged suspension-pivot bridge. Pedal mounts were bonded and riveted to the tub floor with inserts protruding through the front bulkhead to the master cylinders. A tall, arched scuttle panel, bonded and riveted to the dash hoop, enclosed the driver’s leg area.

The 3-litre Cosworth-Ford DFV hung on the back of this chassis nacelle. Great care was taken to grind off all intruding rivets to protect the ATL 40-gallon fuel bag housed between driver and engine. Behind the V8 a complex cast-magnesium adaptor incorporated the oil tank, a Desoutter air-starter motor and the clutch slave unit. Two transverse plates carried the rear suspension pivots. A Hewland FGB five-speed transaxle was used, with high-level gearchange to clear airstream through the side pod.

Suspension was very stiff to react to predicted under-wing download, and front and rear rocker arms acted upon inboard spring/damper units, out of the airstream.

The all-important sidepods housed underwing surfaces made initially in glassfibre but it was too easily deflected by the downloads generated. Through 1980-81 aluminium honeycomb would be used, until replaced by carbon-composite on the 1982 FW08s. A sliding skirt system attached along the outer edge of each underwing tray, to prevent surrounding airflow refilling the low-pressure area generated by the underwings.

Overall, during its long frontline life, from the April 1979 Spanish GP to the April 1982 US GP (West) at Long Beach, the Williams-Cosworth FW07 family would carry Alan Jones to the 1980 Drivers’ World title, and win back-to-back Constructors’ Championship titles in 1980-81, plus 18 races overall, 15 of which were full World Championship GPs.

Initially, the under-developed design struggled somewhat in 1979, until one day that July when Frank Dernie could hardly believe the figures he was seeing. He was at the Imperial College ‘5 x 4’ wind tunnel – in South Kensington – testing a quarter-scale FW07 model.

Reading the pressure-tapping read-outs, Frank recalls: “It became clear that airflow beneath the underbody shape we’d been running was just stalled from the back of the chassis rearwards, around the engine and gearbox. It wasn’t generating any downforce. I’d been in the tunnel trying different underbody shapes – cut with scissors from 12-thou-thick S1C aluminium. We’d do a run, then check the pressure-change figures – and then here was a progressively up-curved and expanding shape which showed a massive gain – not just an improvement, but a truly massive gain!

“I went straight to the works, drew the new shape and we made an undertray fairing in NS4 standard high-strength aluminium that you could bend without it breaking, to fit around the bottom of the engine. From those quarter-scale test results I confidently expected a shedload more downforce, and we rushed the parts to Silverstone just in time for British Grand Prix practice, ’79.”

Frank Williams once outlined that momentous weekend to me like this: “The Renaults won their first Grand Prix, on home soil at Dijon, split by Villeneuve’s Ferrari – and all on French Michelin tyres. Alan had come fourth there, the first Goodyear runner, and Clay (Regazzoni) sixth, unable to do anything about those giant teams up front.

“I thought this was possibly the start of a new age. The industrial giants like Renault, Alfa Romeo and Fiat – operating through Ferrari – with their vast engineering resources, would just kill the established specialist teams like ourselves… But then we went testing at Silverstone, and it really came home to me just how good Patrick’s ’07 was becoming…

“I could not believe my watch. Alan went out and on his second lap did a 14.6, then 14.0, 13.6. 13.2. When he got down to 13.6 I thought ‘This can’t be right, I’d better check these watches’, but there was no mistake, and with the underfairing he was suddenly down to 12.6! Although we didn’t realise it immediately, the improvement was helped by a very strong engine, but by the end of the day Alan was slamming in 12.6s and 12.8s as he liked – against an existing record of 1:18! – and blowing everybody’s mind.”

In qualifying, Alan finally clocked a shattering 1:11.8, averaging 145.55mph for the near 3-mile lap. Both Alan Jones and a Williams car were on pole position for the first time in their respective careers, and Clay Regazzoni in the sister FW07 qualified fourth- fastest, behind Jean-Pierre Jabouille’s Renault and Nelson Piquet’s Brabham.

The Williams FW07 twins then ran first and third early in that race, split by a sweating Jabouille’s Renault until its tyres degraded and on lap 17 he headed for the pits. For 22 more laps Jones and Regazzoni streaked around 1-2, but suddenly it was the rugged Australian’s turn to dive into the pit lane – for the neck of his Cosworth engine’s water pump had cracked, dribbling the coolant away.

Clay Regazzoni – veteran, hard-bitten, popular Clay – blared around untouchable, lap after lap, to win the British Grand Prix. Only days previously Renault had scored its first Grande Epreuve victory, on home soil; now the Williams team emulated that success.

Frank Williams himself was happy but controlled, satisfied for himself and his team but desperately sorry for Alan, whose success this should have been. But he was delighted to have his chief sponsor, Prince Mohammed, present… “Normally he would have left right after the race, but he seemed intrigued by everybody’s reaction. Clay was immensely popular with the crowd, and people were flooding over the banks and massing around the pits cheering for him. The Prince spent a couple of hours with Clay in the motorhome…and then he actually insisted on walking back to the helicopter with me, through all the crowds. He didn’t want to be driven…”

“Clay Regazzoni – hard-bitten, popular Clay – blared around untouchable to win the British GP”

So that first victory for Williams – and for Patrick Head’s Williams-Cosworth FW07 – was both momentous and moving. But, of course, it had been victory in just a minor battle in a major war. The Williams team was hungry for more success – and it followed as Jonesie won the German GP at Hockenheim, with Clay making it an FW07 1-2 – after Renault had taken pole position, and Ferrari set fastest lap.

In Austria, Alan won yet again – Clay fifth. With the cars on the starting grid a rival team manager was found underneath the spare FW07 in the deserted paddock, measuring-up its ‘trick’ underfloor diffuser.

In the Dutch GP, Alan scored his third win in a row, the team’s fourth – but yet again Renault took pole and Ferrari fastest lap. Ferrari then shone on its home ground at Monza, Clay third, Alan ninth after a stop to change battery and spark-box. In Canada the two FW07s finished 1-2 again, Jones ahead of Regazzoni – and in the US GP at Watkins Glen Alan qualified on pole with Clay fifth fastest, but after a mid-race tyre change Jones’s FW07 shed a wheel while Clay – in his farewell Williams drive – retired with damaged steering after clouting Piquet’s Brabham.

That year’s Drivers’ World Championship title went to Jody Scheckter of Ferrari, from his team-mate Gilles Villeneuve – then Alan Jones third. But while Scheckter had won three of that year’s GPs and Villeneuve just two – Alan Jones had won four. The Williams team’s early season disappointments with the carried-over FW06 cars, and then late development of the replacement FW07, had cost the Didcot team top honours.

Into 1980 the FW07B development sought two seconds per lap improvement in winter testing at Ricard. New chassis ’5 and ’6 were the first stiffened ’07Bs, and with an update involving revised undersides and modified cooling systems. For 1980, Williams had 18 available Cosworth DFV engines, 13 being raced, while four were earmarked primarily for the test team, and one was exclusively for “experimental purposes”. A definitive B-spec was first raced in the Belgian GP.

For 1981, to combat the governing body’s sliding-skirt ban, Williams produced the unskirted, ballasted ‘clearance car’ FW07C – new chassis ’11 and ’12 being built to this standard. The family expanded – omitting a chassis number ’13 – until chassis ’17 became (officially) the last built. For 1982 they were replaced by the FW08 – originally intended to be a six-wheeler – but which emerged as a conventional four-wheeler built to run extremely light with an onboard reservoir for its ‘water-cooled brakes’, which would enable it to be brought up to legal minimum weight in time for post-race scrutineering. Oh, what a web we weave…

These FW07s were truly classic Grand Prix cars of which Frank Williams, Patrick Head and their men could be – and are – justifiably proud.