The 2014 Goodwood Revival on 12-14 September will have a treat in store for lovers of curvaceous cars from Coventry. To mark the 60th anniversary of the storied Jaguar D-Type, an unprecedented 30 surviving examples will be entered for the Lavant Cup race.
The D-Type’s importance is hard to overstate, not least because it utilised the first successful monocoque chassis design in motor sport history. An alloy ‘tub’ of elliptical shape and comparatively small cross-section provided an incredibly rigid yet lightweight structure. Sub-assemblies were then bolted to the front and rear – carrying the engine, steering assembly, and front suspension in front of the cockpit while the rear suspension and final drive were carried behind.
In many ways the D-Type was the road-going equivalent of the Hawker Hunter jet fighter and borrowed heavily from contemporary aeronautical design. The man behind the car was Malcolm Sayer, an aeronautical designer from the Bristol Aeroplane Company, had joined Jaguar in 1950 and brought with him the most advanced thinking available in the world. Sayer’s brilliance steered the Jaguar XK120 and its Le Mans-winning sister the C-Type, whose success cemented Jaguar’s reputation and paved the way for his 1954 masterpiece, the D-Type.
It is astonishing to think that Sayer’s work depended upon developing complex formulae for creating curves – exactly the same science that is replicated by today’s CAD software programmes. Back in the early ‘Fifties, however, the only tools that Sayer had to call upon were a slide rule and seven-figure log tables.
Sayer’s handiwork was tested in a wind tunnel. He was determined to minimise the frontal area of the car in order to decrease wind resistance and thereby increase speed on the Mulsanne Straight at Le Mans. This in turn required Jaguar’s Chief Engineer William Haynes and former Bentley engineer Walter Hassan to develop dry sump lubrication in order to cant the 3.4-litre straight-6 XK engine at 8½ degrees from the vertical in order to meet Sayer’s demands – creating the D-Type’s signature offset bonnet bulge in the process.
In addition to the structural similarities between the D-Type and contemporary fighter aircraft, several ancillaries were carried over from aircraft such as Dunlop disc brakes and a Marston Aviation Division bag to carry the fuel instead of a traditional rigid tank.
The dark green cars caused a sensation at Le Mans in 1954 and should have taken victory in the 24 Hours at a canter, but for fuel feed problems resulting from their revolutionary design. Nevertheless the superiority of these high-tech creations was clear to see when they achieved more than 172 mph on the Mulsanne Straight compared with the 160 mph reached by the instantly outdated (but ultimately victorious) 4.9 litre Ferrari V12.
Ongoing development of the D-Types cured these gremlins and, with revised ‘long nose’ styling from 1955 onwards to further increase high speed efficiency and stability, duly conquered the world. Jaguar won Le Mans in 1955, 1956 and 1957 against the combined might of Mercedes-Benz, Ferrari, Maserati and Aston Martin. More important still, it set the template for every successful thoroughbred racing car to this day, both sports-prototype and single-seater.
Today the D-Type remains a popular choice for drivers and fans at historic events. Total D-Type production is thought to have included 18 factory team cars, 53 customer cars, and 16 road going XKSS versions. The Goodwood celebration will certainly be well deserved and undoubtedly a highlight of another spectacular race card.