In time for the 60th anniversary of the SL model, Mercedes-Benz has completed the restoration of the second-ever SL to be built, chassis number 194 010 00002/52, which has remained in company ownership since it was built in the racing workshops in 1951/52.
This involved the vehicle being completely dismantled at the Mercedes-Benz Classic Centre in Fellbach, near Stuttgart, then every single component meticulously examined and, where necessary, restored according to the very highest standards of authenticity and quality. The clear remit was to retain the substance in every respect.
The restoration of the bodywork was a particularly tricky process, as it is made out of extremely delicate aluminum/magnesium sheet metal. Time had also taken its toll on it in many places. It took the specialists around six months to bring the bodyshell of the oldest SL in the world still in existence back to its former glory. The restoration of the vehicle lasted 10 months in all, which, in view of the extensive work involved, represented a very tight schedule.
The Mercedes-Benz 300 SL (W194) was the first motor racing vehicle to be produced by Mercedes-Benz after the end of the Second World War and appeared at a time when Europe still lay in ruins. On 15 June 1951 the Board of Management resolved to participate in motor racing once again from the 1952 season and commissioned the production of the “300 SL Super-Light”, as the new car was initially known. The suffix was later shortened to the simple letters SL – so giving rise to the model designation 300 SL. Its M 194 engine was derived from the engine used in the Mercedes-Benz 300 prestige saloon, also known as the “Adenauer Mercedes”. For its use in the racing car, the engineers increased the output to around 170 hp (125 kW). The racing engine, equipped with dry sump lubrication, is canted at an angle of 50 degrees to the left.
The famous swing-wing doors are a characteristic feature of the Coupé: they are cut deep into the roof, open upwards and were originally conceived purely as access hatches that opened only as far as the beltline. During preparations for the 24 Hours of Le Mans the door openings were enlarged, giving the even more pronounced effect of extended wings. This led to the car being nicknamed the “Gullwing” by the Americans and “Papillon” (Butterfly) by the French. In two races the 300 SL appeared with a Roadster body rather than as a “Gullwing” model.
Lightweight construction was one of the key priorities for the 300 SL. Wherever possible, efforts were made to save weight – the body shell is made out of sheet aluminum/magnesium, some of the mechanical components of aluminum or magnesium, while various parts are bored to make them lighter.
Another way of improving competitiveness was to make the body as aerodynamic as possible. Rudolf Uhlenhaut, who was the head of passenger car testing at Daimler-Benz at that time, developed a special framework for the W194, weighing just 50kg. This is made out of very fine, high-alloy steel tubes designed to absorb tensile and compression forces.