The Mercedes-Benz sreamliner which Stirling Moss drove at the Goodwood Festival of Speed — and which was driven for this feature by Hans Herrmann in the works complex at Stuttgart-Untertürkheim — is chassis 10 of 15, including one prototype. When the Rennabteilung had to close its doors in October 1955, 10 were still in immaculate condition: six of them were open-wheelers, four were Streamliners. Of the Streamliners, two still belong to the works, one is at the Indianapolis Motor Speedways Hall of Fame and the other is at the Technical Museum in Vienna.
The two bodywork configurations were easily interchangeable, depending on race strategy, the peculiarities of the circuits and the likes and dislikes of individual drivers. In open-wheeled form, chassis 10 was driven to fourth in the 1955 Argentinian Grand Prix by Herrmann and to second by Moss in the Belgian and Dutch grands prix. It served as a practice car for the Italian Grand Prix fitted with streamlined bodywork.
Having lain dormant in the same condition in which it had been pensioned off some 40 years before, apart from various show and exhibition appearances such as at the Balcarce Fangio Museum, its magnesium bodywork had fallen into disrepair. “Its skin had become utterly fragile because of ageing, travelling and being exposed to ever-changing climate conditions,” says Gert Straub, technical director of the Mercedes-Benz Classic Centre’s workshop, who set out to restore the car in 1999. In a way the process was a return to basics. In 1954 the original plan had been to provide the W196 with aluminium bodywork. But kitting it out in magnesium turned out to be 20kg lighter, so the Streamliner’s body weighed only 40kg. But using magnesium as a material was not easy because it took a constant 250deg C to produce a viscous dough which could be shaped over a wooden mould. When drops ignited, such was the heat that the fire could only be put out with sand. Since weight is no longer a problem, and the original skin had been treated with a liquid the composition of which has long since been lost, Straub’s team opted for aluminium.
The original bodywork, which has been stored and preserved, was scanned by laser beams, and using that data, Drescher, a company based in the little Black Forest town of Hinterzarten, reproduced chassis 10’s bodywork. The work took one year, about 1000 man-hours.
Another 1500 hours were invested in restoring the engine and the complicated lattice-work of the chassis — dismantling, scrutinising and repairing after covering it with magnesium powder.