It was the year 1952, and Mercedes had just won a series of prominent international racing events with their W194 racecar. And that's all it was, a racecar, an experiment; they had no plans to put the car into production. But thankfully fate intervened.
A New York City-based automobile importer named Max Hoffman had recently signed a contract to import Mercedes' cars to the U.S.A. As a former racecar driver himself, Hoffman's attention was then captured by the W194's victories making the news rounds. I'm guessing Hoffman was eager for a chance to drive the car himself, but the fact is that he knew cars as well as he knew customers, and he felt strongly that a roadgoing version of the W194 was something his well-heeled clientele would line up to buy.
He lobbied Mercedes to build one, and while they were initially resistant, Hoffman employed some clever tactics to get them to agree. (That story, and Hoffman's subsequent influence on auto design history, is fascinating enough that it will get its own entry later.) Based on Hoffman's prompting Mercedes greenlit the W198, a road-ready version of the W194.
Now we turn to why the car has gullwing doors in the first place. As we learned in the entry on its W194 antecedent, the car was constructed using an unusual system of alloy tubes assembled into interconnected triangles. This gave the frame the necessary rigidity at an extremely low weight. But in order to achieve enough rigidity in the areas flanking the passenger compartment, the framing had to extend upwards much higher than your average car door's sill. This precluded the possibility of designing a car door that would allow sufficient room for the driver and passenger's ingress and egress.
In the roofless versions of the W194 racecar, this was no problem: The driver could climb in and out.
For the enclosed W194 versions, like the one below that took second place in Italy's 1952 Mille Miglia endurance race, Mercedes engineers had to work out a point of access.
Mercedes chief engineer Rudolf Uhlenhaut and his team looked at the problem: creating a conventional door above the high sill line was not an option—the resultant aperture would be too small for any human, even a racecar driver, to be expected to clamber through. They clearly needed to enlarge the aperture, but there was no way to go down, not without compromising the frame. The only way to go was up, incorporating a chunk of roof into the door. That would make a hole large enough for a driver and co-driver to get into. But how the heck would you hinge such a thing?
They then decided to hinge the thing at the top. I cannot stress enough how radical a design twist this was in those days, when every other car door opened on a horizontal plane.
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