Starting life as a 300 SLS Le Mans works racer, this prototype 300 SL was later used by a legendary war photographer for a famous road trip across the Alps. Today we recreate that journey
It’s a glorious sunrise on an early spring day when I arrive at the shore of Lake Como in Northern Italy. I’m about to take an amazing drive on the Stelvio Pass to celebrate a legendary photojournalist and a one-off car. The photographer was American David Douglas Duncan, now 101 years old, best-known for his World War II combat pictures but also a motoring enthusiast. The car is a 1952/1955 Mercedes-benz 300 SLS, and the pair were last together, here, in 1956. This Mercedes is the original 1955 prototype used to develop the 300 SL Roadster for which Duncan, aka DDD, was to provide crucial publicity in the US. And it has lived a very full life, having started as a 1952 300 SL racing car, chassis 00009/52. Originally built as a Coupé and wearing the W83-3786 number plate, it was entered into the 1952 Le Mans 24 Hours, with racing number 20. It finished second overall in the hands of Theo Helfrich and Helmut Niedermayr, and was classified just one lap behind the winning sister car of Hermann Lang and Fritz Riess.
Then, on 3 August the same year, it was entered with an open body as number 22 in the 1952 Sportwagen Grosser Preis von Deutschland at the Nürburgring. Driven by Riess, it finished in second place, another Mercedes one-two behind Lang’s car. It was then entered as car number 6 in the 1952 Carrera Panamericana with John Fitch and Eugen Geiger. Mercedes scored yet another epic one-two here, but the Fitch-geiger No 6 failed to finish. This was its final works race, because at the end of the season Mercedes withdrew from competition. The 300 SL had proved itself, though.
Close up, you can spot the small differences from a standard 300 SL. While it appears to be a regular 300 SL Roadster, there isn’t a single panel that’s identical to the production version. ‘It looks standard, but it’s not,’ says proud owner Alberto Cefis, president of the 300 SL Club of Italy and my co-pilot for the trip.
‘Differences start from the material used for the body – this is the only 300 SL Roadster body totally made in steel, doors included, without a single alloy component.’ As soon as we open the doors, we enter a new world – and it’s a low and refined one. The whole cockpit is made up of special parts, many of them unique, from the steering wheel and the ashtray to the door
‘At Le Mans it finished just one lap behind the winning SLS sister car’
‘There are pictures of John O’shea testing the car, paired with Uhlenhaut, at the Solitude and Monza race tracks’
handles and position of the instruments. The seats are different too, with only the driver’s one adjustable. The starting procedure is almost disappointing because of its simplicity. Contact, a few seconds to allow the fuel pump to pressurise the system, and a loud bark erupts around me. I move off slowly, waiting patiently for the temperature needles to rise, but I immediately recognise the familiar feeling of a normal 300 Roadster beneath me.
We enter the first tunnel on the twisty lakeside road taking in the intense soundtrack, round and full, as the revs climb. My expression clearly shows my appreciation. ‘You should hear it with the open side-exit exhaust,’ says Alberto, referring to the system used in period racing. ‘It takes a lot of heat from under the car and from the cockpit… but it’s not strictly homologated.’
The drive to reach our destination takes a couple of hours, giving me plenty of time to learn more about this unique car. Its chassis is very similar to the one ultimately adopted by the production version. Although I’m not about to push it hard enough to identify distinct handling nuances between the developmental and final versions, cornering is pleasingly level and the ride is firm without being overly harsh. It’s commonly accepted that the roadster’s handling is better than the coupé because of the advanced rear suspension that this very car pioneered.
The engine is the regular six-cylinder, although it sounds slightly more aggressive than in production form. It pulls so strongly from 2000rpm that I’m able to overcome even the steepest gradients in second or third, and still leave a 1000rpm surplus of mechanical sympathy before the 6400rpm redline. Pressing on across the passes, I’m grateful for the Dunlop disc brakes inherited from the later coupés.
The clutch is also mercifully light too – though, unlike the production cars, the gear lever is a long item that stems from beneath the dashboard, and as a result it’s slower and has more play. But stirring it is an emotional experience, because it’s a direct reminder of this car’s racing pedigree. Overall, the driving experience is 98% the same as a regular 300 SL, but that remaining 2% provides an enjoyable rawness.
There are numerous documents from when this SLS was in Mercedes-benz ownership. The first private German owner, in 1965, knew about the origin of the car, but we are not so sure about the second, who bought it in 1969. What we do know is that its origins came as a complete surprise to the third owner, an American collector. He had been able to track its history thanks to Mercedes-benz historian W Robert Nitschke.
The car was sold again, in 1987, to US restorer Scott Grundfor, who dug further into the car’s history, retrieving photographs and samples of the original paint and leather along the way.
Since the very beginning of the project to produce a road-going version of the 300 SL, Max Hoffman, the American importer for Mercedes, had been pushing for an open version. In September 1953 Rudolf Uhlenhaut, the technician in charge of testing the new ‘Gullwing’ coupé, asked where the 1952 racing 300 SLS had got to. In an official reply he was told that one, identified as chassis 9, had been assigned to Hans Rottweiler, head of the future development department. In June 1954, just a month after production of the 300 SL Gullwing had begun, the Mercedes board gave a green light to the development of an open 300 SL, forecasting the manufacturing of three prototypes.
The first Roadster was completed on October 29, 1955, shown to the board on November 2 and registered two days later. Within a couple of days there was an internal report outlining the need for modifications – among them the soft-top opening mechanism, the positioning of the instrument cluster and tweaks to the chassis to silence a few squeaks. The note also reported a smell of fuel when the car was driven with a full tank.
As the man in charge of dynamics, Uhlenhaut first tried to modify a 300 SL Coupé chassis, but without the rigidity offered by
‘There’s a threehour drive back home, but nobody’s upset’
the roof, and with the sill lowered to allow the use of normal doors, it flexed too much. He then replaced most of the tubes forming the chassis, but in doing so, the overall weight increased by about 100kg – that was just too much. From there on, a multitude of chassis were designed and tested in a bid to find the best combination of rigidity and weight. A note dated July 2, 1956 shows the test results of five different chassis. Just one, the third, achieved the desired rigidity and that was the one installed on the Roadster for a 6000km road trial.
Even though the chassis has changed, this SLS retains some of its original racing components, such as the lighter front suspension reserved for the racing cars. This prototype was the car used to study the shape and the details of the interior of the 300 SL Roadster, and has many differences from what became the standard production car.
In late spring 1956 the car was re-registered, and received the number plate W27-4603. But duties for the prototype – most likely the only one built because there are no traces of the other two planned cars – were not yet over. In October 1956 American racer Paul O’shea visited Europe to define the specification of his racing car for the following season. There are pictures of him with the car, paired with Uhlenhaut, at the Solitude and Monza race tracks. Testing must have gone well, because he asked Mercedes to make two SLSS for him to use in the 1957 American racing season. In 1965 this car was sold as an O-series (internal code for prototype).
Early in 1956 DDD was due to collect his new black 300 SL Gullwing in Stuttgart, the car that became his daily driver and is now better known as ‘Picasso’s 300’. The M-B press department pounced on the opportunity to have the renowned war photographer’s coverage of the new 300 SL published in the USA, the market for which the car was intended.
The problem was the new car wasn’t ready, so instead, the prototype was used. The article was published in Collier magazine in October 1956 and in Road &
Track in March 1957. Unusually for the time, some of the pictures are in colour – and they’re of the car on the Stelvio, driven by legendary Mercedes engineer Rudolf Uhlenhaut and chief designer Karl Wilfert.
The arm-twisting climb to the top demands all of my attention – there’s no time to look for the vantage points used by DDD 60 years ago. After 48 hairpin bends it’s time to let car and driver cool down. We’re surrounded by onlookers, attracted by the 300’s shape. Among them is a family visiting from the Netherlands, with their dog. Luckily, it’s more friendly than Uhlenhaut’s German Shepherd which, lore has it, tried to bite DDD.
We take the opportunity to use him as a model, before slowly driving down on the other side of the Stelvio. The scenery here has barely changed in 60 years and nor have the roads – save for minor improvements in places such as widened tarmac, and new stone walls and guardrails.
This is the second-highest road in Europe at 2557 meters above sea level. The SLS remains indifferent, thanks to its clever fuel injection system which automatically compensates for the reduced atmospheric pressure. When we do find what we believe are the same photo locations, we appreciate how brave DDD must have been to achieve those speeds.
When the day and the duties are almost over, we find ourselves on the ‘wrong’ side of the Pass. It’s a three-hour drive back, but neither of us is complaining – and the car feels even more eager to go than we do. In fact, we are still driving top down when we hit a light shower. The aerodynamics are good enough to keep us dry as long as we stay above 35mph, and that’s easy enough on the straights – less so on the hairpins of the final stretch of the Stelvio. We’re enjoying the experience so much that we carry on regardless. We bet DDD and his crew would have done the same.
The period articles were so successful that Mercedes received several orders, with letters requesting the car in the same Metallic Blue DB353 paired with Blue leather 333. Back in the garage, we realise we’d driven the all-steel protoype all day long without refuelling, using nearly all its 110 litres. Once topped up, another of the car’s original features returns – the heady whiff of petrol.
There are few mechanical differences between prototype and production 300 SL
There have been very few changes to the scenery in six decades, peripheral street furniture aside
Replicating the pace of Uhlenhaut seen in the Collier article (below) is no easy feat