Mercedes-Benz W 196 R Streamliner
By DaimlerChrysler AG, Stuttgart
On July 4, 1954, over 300,000 eager motor racing fans descended on Reims in anticipation of the start of the 41st ACF Grand Prix. The race on the triangular circuit promised a feast of entertainment since, in addition to the Italian Ferraris and Maseratis and the French Gordinis, Mercedes-Benz was now also making a re-appearance for the first time since 1939. Three Silver Arrows with spectacular state-of-the-art streamlined bodies were to take on the opposition; the cars’ designers were convinced they would prove more than capable of upholding the Mercedes tradition and continuing the legend of the Silver Arrows and their winning formula.
Sure enough, in what proved a sensational first outing, Mercedes driver Juan Manuel Fangio broke the 200 km/h mark on a European road circuit within the first hour of time trials to join Karl Kling on the front row of the starting grid alongside the 1953 world champion Alberto Ascari in a Maserati. The third member of the team, rookie Hans Herrmann, surprised even himself by taking the fifth position in the starting line-up, hemmed in on all sides by Ferraris and Maseratis.
With 61 laps and 506.42 kilometers to cover, the starter’s flag got the race underway at 2:45 p.m. Fangio and Kling immediately took the lead and proceeded to hold on to it for the rest of the race. Ascari was forced to retire during the first lap, and by lap seven Hans Herrmann had moved up to third place, recording the fastest lap of the day in the process. But he had perhaps demanded too much of his engine, which, given the time pressure the team was under, had undergone less than thorough testing in preparation. His car finally gave up the ghost on lap 17.
To the delight of the German fans, the lead changed hands constantly between Fangio and Kling. In the end, it was Fangio who took the checkered flag just one hundredth of a second – less than a meter – ahead of his teammate. A one-two win at the first attempt for the Silver Arrows! And there were five more such double victories to come in the remaining races of the 1954/55 season, not to mention the four single wins and the sprinkling of second, third, and fourth places – in total, 10 wins from 13 Grand Prix races.
With the in-house designation W 196 R, Mercedes-Benz staged a comeback in an impressive style. To the general delight of the race-going public and press alike, new life had been breathed into the legend of the Silver Arrows.
Hans Herrmann Reminisces
Han Herrmann, born in 1928, was a trained pastry cook as well as a gifted racing driver. He painted the following picture of the early days of his career in motor racing.
“As a boy, I always wanted to be a racing driver, in the same way as other boys wanted to drive steam engines. So I became one. But before I was allowed to take it up I was told I had to learn a “proper job,” so I was trained as a pastry cook. But my passion for cars was already deep-rooted. My first fast car was a Porsche, with which I had some really fantastic wins. I suppose my best as a private driver was the class win at the 1953 Mille Miglia, and my first win as a works driver for Porsche at the Le Mans 24 Hours, where I won my class.
One day, the telephone rang. I answered it to find Neubauer, the Mercedes racing manager on the other end. He was calling to ask if I was interested in going to the Nübergrine to do some test driving. They were still looking for a third driver for the 1954 Formula One. I was utterly speechless. But eventually, I was able to stammer a “yes, yes, yes!” Just two and a half years after my racing debut I had been handed a passport to Formula One.
I got my first experience of Mercedes’ new racing car early in 1954 on the Hockenheimring. It was a fantastic machine with great road-holding capabilities. And the best thing about it was its seemingly unlimited power. I had never experienced so much horsepower under the seat. Driving it was such a joy I even managed to go faster in practice than my teammate Karl Kling. It’s also to him I owe my life.
The story goes like this. There used to be a number of access roads to the surrounding fields at the old Hockenheimring. These roads were simply cordoned off with a wire to make sure that nobody got onto the circuit by mistake. Kling noticed this and had the wires removed so that – as he explained later – they didn’t block possible emergency exits or threaten to chop drivers’ heads off. I was once forced to use one of these emergency exits when an old hose burst during practice. I was unable to brake going into a bend because the brake pedal was covered in oil – quite apart from the burns to my leg!
Never mind, though. I was fit again in no time and able to join Fangio and Kling for the race at Reims – the first time the Silver Arrows had competed since the war. I managed to record the fastest lap there, before my brand new – though not fully tested – engine packed in. That was how my racing with Mercedes all started. Those were wonderful times.
Superior Mercedes-Benz Engineering
Mercedes-Benz re-entered the fray with an eight-cylinder in-line engine, the most characteristic features of which were its central drive, two rows of four cylinders, each with two camshafts for intake and exhaust, two valves per cylinder that were mechanically-operated with desmodromic valve control rather than conventional valve springs, dual ignition, dry sump lubrication for both engine and transmission, and mechanical direct fuel injection as icing on the cake. Together these features enabled a more robust unit with more even power development over the full engine speed range and avoided the dreaded “flat spot” at lower revs – a particularly worrisome feature of the conventional carburetor engines of the day.
On its first outing at the 1954 French Grand Prix, the 2.5-liter engine developed an output of 257 hp at 8250/min. By the summer of 1955 this had increased to 290 hp/min at 8700/min, due in no small measure to the ongoing optimization of the intake manifold and the improved cylinder charge. It reached maximum torque of 25.2 mkg at just 6300/min. And by the end of its development, engine weight had been reduced to 195 kg from the original 204 kg.
Power transmission was via a single-plate dry clutch and prop-shaft beneath the driver’s seat to the five-speed gearbox with locking differential, offering a number of possible gear ratios. The shift lever was mounted in a gate with first and reverse gears locked by means of a pawl.
The car had double wishbones for the front wheels, torsion-bar suspension front and rear and damping by means of hydraulic telescopic shock absorbers – which was nothing short of a mini sensation back in 1954.
An intermediate shaft together with a constant-velocity joint linked the front wheels with the large, ribbed light-alloy brake drums mounted inboard between radiator and engine. Whilst this added to the overall weight, it also minimized unsprung masses and resulted in exceptionally good handling characteristics.
An innovation at the rear of the car caused quite a stir in the motor racing world. While the opposition favored the De Dion rear axle, Daimler-Benz used a very light single-joint swing axle with a low fulcrum and slight negative cam of the wheels. This proved highly successful and, for many years to come, was to be a defining element of subsequent series-produced vehicles. Rear brakes were also mounted inboard.
Another factor contributing to the car’s success was the use of problem-free 16-inch wire spoked wheels with 5-inch rims. These were fitted for each race with the extremely reliable and hard-wearing Continental tires, each set specially selected for each circuit. The exceptionally light 36-kg tubular space frame was developed from the corresponding design of the 300 SL racing sports car of 1952. The engine was inclined steeply, giving a very low front end in both the streamlined and the later monoposto bodies.
Sheet metal working was the preserve of a particular group within the racing department – a team of dedicated specialists responsible for the construction of bodies, fuel and oil tanks, intake manifolds, water expansion tanks, seat wells and, not the least, ornamental features – indispensable accessories for the Mercedes-Benz racing cars.
For these “metal bashers,” as they were affectionately known by their colleagues in the engine and chassis department, complete mastery of the full-range handcrafts was taken for granted – from making the preliminary sketches and wooden models right through to production of finished metal components.
For each body – whether streamlined, monoposto or racing sports car – the first step was to produce a full-scale wooden model which could be subdivided into various longitudinal and transverse segments. These not only followed the lines of the necessary welding seams, but also matched the cutout contours of the engine hood, the side segments of the body between wheel arches down to the underbody, front- and rear-end design, engine compartment air vents, as well as the cutouts for the doors and the trunk lid in the case of 300 SLR.
Individual models with identical contours were used to produce the U-shaped profiles required to strengthen the edges of engine hood and trunk lid, side sections and underbody, since all versions of the car were also paneled on the underside as far as possible. Originally it had been planned to build the bodies from sheet aluminum – the tried-and-tested method used for decades. But on this occasion, things turned out differently.
The supply industry had developed a way of producing metal sheets from the relatively brittle but very light element magnesium. Having the same strength as sheet aluminum, it weighted only half as much. The complete body of the streamlined version, for example, weighed a little over 40 kg; the most recent copy made of aluminum weighs around 60 kg. These magnesium metal sheets came in various strengths, with the outer surface protected ex factory, and they were of two types: suitable for welding or not suitable. Daimler-Benz opted for the former.
One could devote an entire chapter to the processing of these metal sheets. When cold they were hardly malleable at all, let alone capable of being hammered into shape using a mold, as in the case of aluminum. But things improved when the metal was heated to a temperature of 250 degrees Celsius, at which point the sheets could be drawn or pressed into a mold with very little effort. It also retained its shape well on cooling, without showing any tendency to “spring back.”
In practice, of course, it was impossible to measure the “correct” temperature for working the metal, so the “metal bashers” resorted to a simple trick. They would heat the sheet by means of a large-bore welding torch at low heat and then draw the handle of a finely polished wooden hammer across its surface. If a dark brown trace appeared, the metal was at the right temperature.