Mercedes-Benz W 196 R streamlined racing car, 1954
Once production had been restarted after the end of the Second World War and the reconstruction of the destroyed factories was in full swing, Daimler-Benz also began planning to resume its motor racing activities. With the aim of building on the spectacular successes of the pre-war period, thereby promoting the company's image and boosting sales, especially in export markets, the company also had its sights set on the top categories of motorsport from the outset.
However, participation in the Automobile World Championship, as the Formula 1 World Championship introduced in 1950 was officially called, was initially out of the question – mainly because an extension of the Grand Prix formula, which had been in force since 1947 and was scheduled to run until the end of 1953, had long been the subject of controversial discussions both inside and outside the responsible motorsport bodies. The key factor in the racing formula at the time was a displacement limit of 1.5 litres for supercharged engines and 4.5 litres for naturally aspirated engines.
The Automobile Club of Germany had already submitted a motion to the meeting of the Commission Sportive Internationale (CSI) in October 1950 to extend the existing racing formula until the end of 1955. However, the issue was not addressed until a conference in Brussels on 17 February 1951, at which France and Italy proposed replacing the current Formula 1 with a new racing formula from 1954, which would replace the former Formulas 1 and 2. The new proposal limited the displacement for naturally aspirated engines to 2.5 litres, and for supercharged engines to a barely competitive 750 cc.
As Germany did not yet have the right to vote in Brussels and only England was in favour of retaining the current formula, a majority of votes were in favour of the proposal to end Formula 1 at the end of 1953. The next meeting of the CSI at the beginning of October 1951 revealed an even clearer picture: Of the nine national clubs entitled to vote, six voted against an extension, with two abstentions, and only the British representatives voted in favour. This paved the way for the new racing formula, even though the CSI did not make the final decision in favour of the new formula until its meeting in October 1952.
After Mercedes-Benz had realised in July 1951 that the existing pre-war 1.5-litre W 165 racing car would at best be equal, but not superior, the focus in Stuttgart for the 1952 season was initially on sports car racing, for which the 300 SL racing sports car was developed on the basis of existing components from passenger car construction. With this decision, the Untertürkheim team also proved to have a lucky hand in that the World Automobile Championship developed in an unforeseen direction after the end of the 1951 season.
After Juan Manuel Fangio had won his first world championship title in 1951 with the Alfa Romeo Tipo 159, it was clear to those responsible in Milan that their 1.5-litre racing car had reached its performance limit and would probably no longer be competitive in the following season. Against this backdrop, the Milan-based company surprisingly announced after the end of the season that it was withdrawing from the World Championship.
In order to counter the expected absolute dominance of the Ferrari team and to enable smaller manufacturers to take part in the World Championship, the CSI gave the organisers of the races that are part of the World Automobile Championship the option of organising them in accordance with the Formula 2 regulations. This limited the displacement for naturally aspirated engines to 2 litres and for supercharged engines to 500 cc. This measure considerably enlarged the starting field, but did nothing to change the dominance of the team from Maranello: The newly developed Ferrari 500 with a 2-litre engine helped Alberto Ascari to the world championship title twice in 1952 and 1953; he also achieved 2nd to 4th place in the overall standings in 1952 and 3rd to 5th place in 1953.
After the CSI had made the 2.5-litre formula binding in October 1952, it was first necessary to wait and see whether a sufficient number of manufacturers would be prepared to bring a racing car to the starting line in accordance with the new formula. A 2.5-litre racing car had already been given thought to in Untertürkheim in October 1951. Fritz Nallinger, Head of Development, had already formulated important key points at that time: They provided for a lightweight and torsionally stiff tubular frame, an interchangeable front axle construction, which could optionally be used as a variant with driven wheels, so that four-wheel drive was available if required – for example in wet races. The brake drums for both axles were to be moved to the centre of the vehicle in order to keep the unsprung masses low. In favour of a low bonnet and a correspondingly small frontal area, the engine was to be installed at a strongly slanted. Two different body variants were already planned at this early design stage: a streamlined body and a classic version with open wheels.
In January 1953, the Daimler-Benz Board of Management took the decision not to build the further developed version of the 300 SL racing sports car and accordingly to refrain from participating in sports car races in the new season. Instead, the construction of a new racing car based on the 2.5-litre formula was to begin in good time. The company announced its decision to take a break from racing in 1953 in a press release at the end of January, followed by a further announcement in May, in which the development of a Grand Prix racing car with a 2.5-litre naturally aspirated engine was announced. The decision taken by the Board of Management in March to build a racing sports car of a similar design alongside the Grand Prix car was not made public for the time being. Both vehicles were given the internal designation W 196 – the Grand Prix racing car with the suffix R and the racing sports car with the suffix S.
At the same time as the Board of Management took this decision, the design work was being finalised with the definition of a detailed timetable, which set a deadline for the completion of the engineering drawings for the engine, transmission and chassis frame. The concept essentially followed the principles already discussed in October 1951, but the possibility of a driven front axle to be used if required was not realised.
A short-stroke, in-line eight-cylinder engine with a centre output was chosen for the completely redesigned engine. With this combination of two four-cylinder blocks, in the centre of which the gearwheels for power transmission to the rear wheels and for driving the camshafts, the water pump and the injection pump were arranged, the aim was to avoid the sometimes problematic vibration behaviour of a classic in-line eight-cylinder engine.
In its basic design, the M 196 followed the principles used in Mercedes-Benz racing engines for a good 30 years, in which steel cylinders and cylinder heads were welded together to form a single unit and fitted with welded-on water jackets. The engine had hemispherical combustion chambers and only two – albeit very large – valves per cylinder instead of the usual four valves. As a special feature, they were not only opened but also closed again via a desmodromic positive control – known as Z-control. This made it possible to dispense with failure-prone valve springs and thus achieve a higher engine speed level of almost 9000 rpm. Another special feature was the mixture preparation, which here – as on the revised 300 SL for the 1953 season and the brand new 300 SL production sports car – was effected by means of direct petrol injection. In contrast to the sports car engine, the M 196 was equipped with two spark plugs per cylinder, which were supplied by a magneto due to the lack of a battery. The crankshaft was mounted on roller bearings and designed as a multi-piece Hirth crankshaft. The output of the new eight-cylinder engine was 257 hp/189 kW at 8250 rpm.
As in the pre-war Silver Arrows, the transmission with five forward gears was separated from the engine to optimise weight distribution and formed a single unit with the differential in a transaxle design. As was also the case in the 1930s, a double wishbone axle with trapezoidal links of different lengths was used as the front axle, although the springing was provided by torsion bars and was combined with hydraulic telescopic shock absorbers for the first time in a Mercedes-Benz Silver Arrow. The rear axle was designed as a single-joint swing axle with a low pivot point, as already featured in a similar form in the further developed 300 SL racing sports car and the new Mercedes 220 passenger car. In the W 196, the axle construction was equipped with a levelling device that adjusted the torsion bar springs as the fuel tank emptied so that the negative camber remained constant.
When the W 196 R was presented to the public for the first time in mid-February 1954, it was a truly extraordinary appearance. This was mainly due to its streamlined bodywork, which was developed especially with very fast racetracks in mind. At its premiere, the streamlined car had neither a windscreen nor the wing mirrors that are so important in racing. Instead, a large chrome-plated Mercedes star adorned the cooling air intake in the front of the car. By the time of its racing debut, which took place on 4 July 1954 in the fourth race of the season – the French Grand Prix in Reims – the star had been removed again, while the windscreen and wing mirrors had been added.
On 4 July 1954, the W 196 streamlined racing car scored an impressive one-two victory by Juan Manuel Fangio and Karl Kling, who crossed the finish line within tenths of a second of each other. Junior driver Hans Herrmann, who had set the fastest lap in Reims, retired with engine damage. The new Silver Arrow thus continued the tradition of important Mercedes and Mercedes-Benz racing cars and, as in 1914 and 1934, clinched victory at its very first start. On the same day that the Silver Arrows crowned their first Formula 1 outing with this spectacular one-two victory, the "Miracle of Bern" also took place: The German national team became football world champions in the final against Hungary. These two remarkable sporting successes enhanced Germany's reputation, which had been permanently damaged by the war – not only in the world, but also in the country itself. Historians sometimes regard 4 July 1954 as the actual end of the immediate post-war period.
The fact that the streamlined car was not unbeatable and reached its limits on twisty racetracks in particular was demonstrated on 17 July 1954 at its second outing, the British Grand Prix at Silverstone, where Fangio and Kling only finished 4th and 7th. The streamlined body could only make limited use of its advantages on the 4.8-kilometre circuit with its short straights and numerous bends, and the cars were also at a disadvantage compared to vehicles with open wheels because they could not be manoeuvred around the bends with sufficient precision due to the closed wheels.
A variant with open wheels planned from the outset was already in the final phase of development, but was not yet ready for use and only made its racing debut 14 days later at the European Grand Prix at the Nürburgring. For the French Grand Prix, with its very fast racetrack in Reims, it was obvious to focus on finalising the streamlined car first.
During the rest of the season, the streamlined version was used twice more in addition to the classic version – both times with Hans Herrmann at the wheel, while his team-mates Fangio and Kling drove cars with open wheels. Towards the end of the season, however, the streamlined cars achieved an impressive triple victory in the AVUS race in Berlin, which did not count towards the world championship: Kling won the race ahead of Fangio and Herrmann.