Mercedes-Benz W 196

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Mercedes W 196 Monza with streamlined body at the Retro Classics 2019
Cockpit of the W 196 with a large Veglia tachometer
Mercedes W 196 Monza with streamlined body

The Mercedes-Benz W 196 was a Formula 1 racing car for the 1954 and 1955 seasons . In addition to the typical monoposto or single-seater with free-standing wheels, it was initially available as a fully faired streamlined version . The two-seater racing sports car Mercedes-Benz 300 SLR for the sports car races of the 1955 season was derived from this.

prehistory

See also: Silver Arrow

The motorsport activities of Mercedes-Benz after the Second World War began in Argentina in 1951 after Germany was initially denied participation in international sporting events. At the Peron Cup on February 18, 1951 and at the Eva Perón Grand Prix on February 25, 1951, the W 154 started in 1939 and took second and third places behind Gonzales with Hermann Lang and Juan Manuel Fangio and Karl Kling and Hermann Lang Ferrari. The W 165 , with which Hermann Lang won the Tripoli race in 1939, was no longer used, although the 1.5-liter supercharged engine would have complied with the Formula 1 regulations from 1947 to 1953.

In 1952, Mercedes-Benz achieved sensational success with the 300 SL W 194 sports car. The 175 hp engine, which was still equipped with carburettors, was based on the series six-cylinder of the 300 S sedan and was not the basis for a future sports car engine or a formula -1 aggregate according to the rules that should apply from 1954. That is why the plant stopped racing in 1953 and developed the Mercedes-Benz W 196.

concept

Engine and power transmission

The Formula 1 regulations for 1954/55 allowed engines with a maximum of 2500 cm³ without supercharging or 750 cm³ with supercharger, which corresponded to a halving of the previous sizes (4.5 liter naturally aspirated engines). Fritz Nallinger , Member of the Board of Management for Design and Development, and Rudolf Uhlenhaut as head of the test, like all competitors, preferred the 2500 cm³ naturally aspirated engine. An eight-cylinder in-line engine was built, which was divided into two four-cylinder blocks and delivered the power in the middle in order to avoid excessive twisting of the extremely long crankshaft. To minimize frictional losses, the pistons ran in chrome-plated liners and the shafts were on roller bearings. Instead of valve springs, there was a desmodromic (forced control) with additional cams on the camshaft to close the valves, which made the engine more stable.

Mercedes-Benz W 196 monoposto

The gasoline direct injection of the W 196 was new , a technology which until then had only been used in two-stroke engines in automobile construction . Engineer Hans Scherenberg , who at Daimler-Benz in the 1930s was involved in the development of the first diesel car Mercedes-Benz 260 D and in the design of the DB 601 aircraft engine with direct fuel injection, had to leave the factory after the war. In 1948 Scherenberg joined the vehicle manufacturer Gutbrod as Technical Director, where he designed the injection system for the two-stroke engine of the " Gutbrod Superior " (1951) together with Karl-Heinz Göschel (1914–2009) and in cooperation with Bosch , the first series-production gasoline injection in the Automobile manufacturing. In 1952 he came back with a team of specialists from aircraft engine construction. Göschel, who succeeded Rudolf Uhlenhaut in 1972, played a key role in developing the injection system for the W 196 in 1953/54.

The fuel in the W 196 was not commercially available gasoline, but a special mixture supplied by Esso called RD1. As far as known, the ingredients were:

Since this mixture attacked the tank and fuel lines, these had to be washed out with "normal" gasoline after each use to prevent corrosion. The eight-cylinder in- line engine initially developed around 260 hp.

In order to keep the vehicle's center of gravity as low as possible, the engine was inclined 53 ° to the right and offset to the left.

The power was transmitted under the driver's seat to the final drive (with limited-slip differential) via a single-disk dry clutch (diameter 240 mm) and a cardan shaft offset from the front left at an angle to the center. The five-speed gearbox (second to fifth gear synchronized) was interlocked with the axle drive and placed behind it. The gradation of the manual transmission and the axle ratio could be adapted to the respective race tracks.

chassis

As was common at the time, the chassis of the W 196 essentially consisted of a tubular space frame, the individual tubes of which had a diameter of 20 and 25 mm (wall thickness 0.8 and 1.0 mm). This frame contained the engine, radiator, gearbox and final drive, brakes, as well as a fuel tank (up to 220 liters) and an oil tank (40 liters). The front wheels were suspended from double wishbones; at the rear a swing axle or single-joint pendulum axle with a low pivot point was installed. In order to move the pivot point to the longitudinal axis of the vehicle and thereby lengthen the pendulum arms, the axle housing (differential gear) swings with this construction.

The W 196 had longitudinally positioned torsion bars at the front and rear, hydraulic telescopic shock absorbers and a hydraulic steering damper. To reduce the unsprung masses, the large drum brakes (front diameter 350 mm, rear 275 mm) were located on the inside, and in the case of the shortened wheelbase (1955) also on the outside of the front wheels. Ribs were attached to the light metal casings of the brake drums at right angles to the running direction, which were supposed to attract cooling air and dissipate heat (“turbo cooling”).

body

To reduce aerodynamic drag on fast courses, the W 196 was initially given full fairing instead of the wheels that are usually free-standing in single-seaters, comparable to the pre-war models used on the Avus and on record drives.

However, the fully clad streamlined body was confusing and relatively heavy, so that the planned monoposto version was used on narrower routes, which in 1955 - due to a change in the injection system or relocation of the pitot tube - got the distinctive air intake hood on the right of the bonnet (see photos) . This had become necessary after leaves clogged the cooler opening and the intake opening there in the fall of 1954.

The body panels of the W 196, which were initially formed by hand using wooden blocks, were made of magnesium and aluminum . Later the sheet metal parts were made with metal molds.

Technical specifications

W 196 Streamline Monoposto
Engine: Eight-cylinder in - line engine made up of two four-cylinders with central output
Displacement : 2496 cc
Bore × stroke : 76 x 68.8 mm
Power: 189 kW = 257 PS (1954) to 206 kW = 280 PS (summer 1955)
at 1 / min: 8250 / min or 8700 / min
Max. Torque at 1 / min: 247 Nm (25.2 mkp) at 6300 rpm
Valve control : overhead camshaft (valves positively controlled )
Compression : 9: 1
Cooling : water
Transmission: 5-speed gearbox (and reverse gear), gate shift *
Front suspension: Double wishbones
Rear suspension: Single-joint pendulum axle with lowered pivot point
Front and rear suspension: longitudinal torsion bars and telescopic shock absorbers
Body: Space frame with aluminum planking
Track width front / rear: 1330/1358 mm
Wheelbase : 2350 mm (also 2210 and 2150 mm)
Front / rear tires: 6.00 × 16 / 7.00 × 16
Dimensions L × W × H: 4160 (with streamlined body) × 1625 (without exhaust) × 1040 mm
Dry weight : approx. 700 kg approx. 650 kg
Top speed:  approx. 280–290 km / h

* The shift lever is guided in a metal template (backdrop).

Formula 1 successes

In December 1953, Mercedes undertook the first test drives with the W 196 on the factory premises in Stuttgart-Untertürkheim, before extensive tests were carried out in Hockenheim (February 1954), Monza (May 1954) and on what is now the A 81 motorway near Schwieberdingen . Further attempts in Hockenheim followed. The racing debut of the new car was delayed until summer, which is why Juan Manuel Fangio contested the first races of the 1954 season on a Maserati and was already collecting points.

After all test drives with Weber twin carburettors, the injection system was used for the first time in the tests immediately before the French Grand Prix in Reims-Gueux . According to the previous calculations, the consumption should be 35 l / 100 km, but in fact it was 40, so that the tank capacity of 185 liters was not sufficient for the race distance of 500 km. Refueling during the competition would have cost too much time; therefore temporary additional tanks were installed in the car on the left side of the cockpit the night before the race.

Karl Kling in the W 196
W 196 with 3-liter engine on August 16, 1986 during a demonstration drive with Juan Manuel Fangio

On July 4, 1954 - nine years after the end of the war - the W 196 first competed in a Formula 1 race in France . Already on the starting grid, the flat and wide “ Silver Arrows ” by Juan Manuel Fangio and Karl Kling in the first row made it clear that a new era was beginning, because the competitors were still sitting on relatively narrow, long-legged older constructions. Only the young driver Hans Herrmann with the third W 196 was further behind in seventh place on the grid. Herrmann achieved the fastest lap time in the race to catch up (2: 32.9 min. = 195.6 km / h) and finished in third place, but he retired on the 17th of 61 laps with engine failure. Fangio and Kling finished the 506.4 km race on the high-speed track with a sensational double victory in a time of 2: 42: 47.7 hours or with an average of 186.638 km / h - a success comparable to winning football World Cup by the German national team on the same day in Wankdorf Stadium in Bern .

From now on, the W 196 was considered to be superior to its competitors, but it also had problems. At the next run, the Great Britain Grand Prix in Silverstone , the streamlined fairing was hardly advantageous. The curves marked with barrels on the airfield course could not be optimally located because of the poor overview. Fangio even damaged both front fenders when approaching the barrels and was only fourth, one lap behind; Karl Kling took seventh place.

For the race for the German Grand Prix on the winding Nürburgring on August 1, 1954, Fangio, Kling and the pre-war driver Hermann Lang received a lighter version of the W 196 with free-standing wheels, while Herrmann still had to make do with full fairing, as only three monopostos finished. Fangio was in the lead from the start, but was briefly ousted by Kling, who started from last place of the 20 cars with a leaky tank and drove the fastest lap in the course of his race to catch up with 9: 55.1 minutes (138.0 km / h). Shortly before the end, Kling fell back to fourth place due to a shock absorber damage; Fangio won after 3: 45: 45.8 hours or 501.82 km with a lead of 1:37 minutes over the Gonzales / Hawthorn works Ferrari. Hans Herrmann (broken fuel line) and Hermann Lang (engine failure) retired in the 7th and 11th of 22 laps respectively.

Fangio also won in Switzerland and Monza , here again with full fairing. Hans Herrmann finished third on the Bremgarten circuit in Bremgarten near Bern and fourth in Monza. Kling retired in both races with engine failure or an accident due to a broken oil hose. The Berlin Grand Prix at AVUS , for which only ten Formula 1 cars competed, was not part of the world championship . The race ended with a triple victory for Kling (average 213.5 km / h), Fangio and Herrmann - three laps ahead of André Pilette on Gordini . At the end of the season in Spain it was only enough for Mercedes-Benz and Fangio to finish third, but the world championship title was certain. Karl Kling was fifth in Spain, Hans Herrmann dropped out in the 51st of 80 laps with a defective injection pump. The cars had problems with leaves in the radiator opening, which hindered both cooling and intake air. A grille was then attached in front of it and the air intake port moved upwards.

The formula-free race on January 30, 1955 in Buenos Aires , in which the W 196 with the 3-liter engine of the 300 SLR racing car was used, won - like the hot Grand Prix  - Fangio ahead of Moss; Karl Kling came in fourth. At the British Grand Prix in Aintree , newcomer Stirling Moss won for Mercedes after Fangio might have let him go in his home race. The race in Monaco turned out to be bankrupt, because all W 196s retired and Hans Herrmann had a serious accident during practice. After the Le Mans catastrophe , some races for the 1955 Formula 1 World Championship were canceled, including the German Grand Prix at the Nürburgring. From then on there were no more races in Switzerland. Another streamlined model won the season finale in Monza . Thus, Juan Manuel Fangio was also 1955 Formula 1 world champion with victories in four of only six races (Argentina, Belgium , Netherlands and Italy).

Mercedes-Benz 300 SLR sports car

For the new sports car world championship introduced in 1953, a sports car variant was derived from the W 196, the Mercedes-Benz 300 SLR . In contrast to the six-cylinder 300 SL road car with gull-wing doors, the SLR was an open two-seater, whose tubular space frame largely corresponded to that of the Formula 1 car. The wheelbase was 2380 mm. A special feature for use in Le Mans was the air brake , a wide shield behind the driver, which could be set up hydraulically in order to drastically increase the air resistance and to support the braking effect of the drum brakes from high speeds. Unlike Mercedes, Jaguar's competition already had disc brakes .

Mercedes-Benz 300 SLR
Mercedes-Benz 300 SLR Coupé
Mercedes-Benz 300 SLR Coupé
Mercedes-Benz 300 SLR Coupé in the Stuttgart Mercedes-Benz world

The eight-cylinder Formula 1 engine was expanded to three liters or 2983 cm³ (bore and stroke 78 mm) and developed 196 kW (266 hp) at 7450 rpm; maximum torque 295 Nm at 5950 rpm. This was inferior to the much larger engines from Jaguar and Ferrari. The top speed of the 300 SLR was 290 km / h (Le Mans, Mulsanne straight). The engine was designed in such a way (compression 12: 1) that it did not need any special fuel, but ran on premium gasoline. The 3-liter engine passed its last test in the W 196 Grand Prix car in the formula-free race on January 30, 1955 in Buenos Aires.

The first race for the 300 SLR was the Mille Miglia on May 1, 1955 , which Stirling Moss won with co-driver Denis Jenkinson . A few weeks later, at the Eifel race on the Nürburgring, Fangio won ahead of Moss; Kling finished fourth.

The 24-hour race at Le Mans drove Mercedes does not end after which the early evening of June 11 1955 tragic accident in motor racing history had occurred. After a reckless maneuver by the Englishman Mike Hawthorn (Jaguar), the French Mercedes driver Pierre Levegh collided with the much slower Austin Healey owned by Lance Macklin and hurled into the crowd. In addition to Pierre Levegh, over 80 spectators were killed. The Mercedes board of directors then withdrew the remaining SLR that night as a token of respect.

At the Kristianstad Grand Prix on August 7th (Sweden), Fangio and Moss achieved another double victory, which was followed by a triple success of Moss / Fitch, Fangio / Kling and Trips / Simon at the RAC Tourist Trophy in Dundrod (Northern Ireland) on September 17th . On October 16, 1955, Stirling Moss / Peter Collins won the Targa Florio in a Mercedes-Benz 300 SLR ahead of their brand companions Fangio / Kling and secured Mercedes-Benz the World Sports Car Championship .

Uhlenhaut Coupé

In 1955, Rudolf Uhlenhaut designed a coupé based on the 300 SLR, only two of which were built. Uhlenhaut used the gullwing doors from the Mercedes-Benz W 198 presented a year earlier . The engine of this "Uhlenhaut Coupé" developed 222 kW (302 hp) at 7500 rpm. With a top speed of 290 km / h, the car was the fastest road legal vehicle. It served Uhlenhaut as a company vehicle for the trip to work, to the annoyance of his neighbors, who were woken up early in the morning by unmuffled exhaust noises. Mercedes initially planned to use this coupé version in endurance races, but this never happened because the company withdrew from racing in 1955.

Of the so-called Uhlenhaut Coupé, both vehicles built in 1955 still exist, which differ only in details such as the color of the interior, red and blue, and details on the radiator grille. Both vehicles are part of the Daimler AG collection of over 700 vehicles.

Conclusion

After the W 196 had won everything there was to be won with two Formula 1 drivers' world championships (the Formula 1 constructors’s world championship only existed from 1958 , Mercedes would have won if it had been introduced earlier) and the new sports car world championship (except again at the prestigious races of Monaco and Le Mans), the plant withdrew from racing as previously planned in order to concentrate on series development.

The W 196 is considered a milestone in motorsport, the Silver Arrows were often described as superior or even invincible. This was mainly the case in races where the benefits of full fairing were fully exploited. Although the cars had a few other innovations, they were constantly being improved in order to keep the narrow lead. It is also difficult to say what part of the F1 successes was due to Fangio, who won nine of Mercedes' ten victories in 14 Grand Prix (not counting the race in Berlin). Double victories or further podium places were by no means the rule. Without or even against Fangio, Mercedes would have had less success or would have had to sign another top driver as early as 1954. In addition, Lancia gave up completely after the death of Alberto Ascari and handed the promising Lancia D50 over to Ferrari , where he carried Fangio to another world title in 1956.

In sports car races, Mercedes also had Moss, the best driver, on board in 1955, because even then, Fangio was no longer willing to continue to take full risks on long distances and on public roads in view of the risk of fatigue for people and material. In addition, with the three-liter engine, Mercedes was inferior to the larger units of the competition in terms of performance.

For practical reasons, Mercedes-Benz Classic now only shows the W 196 R Formula 1 with the 3-liter engine of the 300 SLR W 196 S or a car from the formula-free race in Buenos Aires, as these run on normal gasoline and does not need the harmful mixture of the 2.5-liter Formula 1 engine. The 3-liter power unit is installed less inclined and higher than the 2.5-liter engine, recognizable by the upwardly bulging bonnet typical of this car. The Formula 1 car is no longer authentic, not even when it comes to the smell of exhaust gas.

literature

  • Michael Riedner: Mercedes-Benz W 196 - The last Silver Arrow . Motorbuch Verlag, Stuttgart 1986, ISBN 3-613-01157-3 .
  • Halwart Schrader: Silver Arrows - The legendary racing cars from 1934 to 1955 . HEEL Verlag, Königswinter 1995, ISBN 3-89365-428-3 .
  • German automobiles 1886–1986 - history, beauty, technology . Unipart-Verlag, Remseck 1986, ISBN 3-8122-0184-4 .

Web links

Commons : Mercedes-Benz W 196  - Collection of Pictures, Videos and Audio Files

Individual evidence

  1. Michael Riedner: The last silver arrow . Motorbuch Verlag, Stuttgart 1986, ISBN 3-613-01157-3 , p. 253.