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    True Greats – Silver Arrows.

    The current Silver Arrows have registered three Drivers’ and three Manufacturers’ World Championship titles in a row – and the race for the fourth is on. This series of successes has its roots in an impressive tradition: from the very outset, Mercedes-Benz racing cars dominated every Grand Prix formula in which they competed.

    Text: Hartmut Lehbrink | Photos: Daimler AG

“Planning replaces coincidence by error.”

As Albert Einstein once said, planning replaces coincidence by error. And the history of motorsport boils down to this – it is an eternal game of cat and mouse between engineers and those who make the rules. A fine example of this is the 750 kg formula for Grand Prix racing cars between 1934 and 1937. As part of this, the motorsport legislators – the AIACR (Association Internationale des Automobile Clubs Reconnus) – pursued two aims. They wanted to beat a simple and clearly defined path through the wildly spreading undergrowth of the existing regulations. And the exuberant speeds delivered by the twin-engined rockets from Alfa Romeo, Bugatti and Maserati provided reason to worry.


Monaco, 08.08.1937: Double victory by von Brauchitsch and Caracciola during the Grand Prix on the city’s circuit.

Pescara, 15.08.1934: Luigi Fagioli drives the W 25 to victory during the Coppa Acerbo on the triangular race track.

Pescara, 15.08.1934: Luigi Fagioli drives the W 25 to victory during the Coppa Acerbo on the triangular race track.


To stage a true feast.

The idea behind the new regulation was that a lighter vehicle would also mean slower speeds. In this point, the authorities were wrong. As only the cars’ weight was prescribed, there was nothing standing in the way of increasing their displacement and thus also their output. This great amount of freedom led the team at Daimler-Benz to stage a true feast. The W 25 – their first answer to the new formula – initially drew 354 hp out of the 3,360 cc displacement of its compressor-charged in-line eight-cylinder engine. In the end, they managed to get 494 hp out of its 4,740 cc displacement. During the training rounds of the three Eifel races from 1934 onwards, 140 hp more gave the Mercedes flagship aristocrat and Nürburgring specialist Manfred von Brauchitsch a half- minute lead. At the time, the W 25 drove to an impressive 16 victories in Grand Prix races and other major race events.


1934: Shooting Star.

For a long time, the W 25 was associated with the saga concerning the origin of the Silver Arrows name. On the eve of the Eifel race on 3 June 1934, the cars are said to have had German racing white paint. But during the weigh-in, they were found to be one kilogram over the imposed weight limit and so the paint had to be sanded off until the car reached the 750-kilogram limit, thus leaving an immaculate silver finish. However, this legend is based solely on the recollections of two Mercedes authorities: Manfred von Brauchitsch and racing director Alfred Neubauer. Much later, the two continued to relate this story and even believed it themselves. And so it became part of the brand’s folklore.


As the victories of the W 25 in the 1936 season became few and far between, Mercedes-Benz came up with a quick and firm response. A racing branch was set up and the testing department established under the watchful eyes of Fritz Nallinger. It also served as a connection to the actual racing team, in which Alfred Neubauer had the final word. The manager was Rudolf Uhlenhaut – a competent technician and manager with mild methods but who was relentless in matters of detail. He could even set record times in the Silver Arrows himself. “Zipping along”, as he called it, is somewhat of an understatement. Test drives on the Nürburgring in mid-August 1936 mercilessly uncovered the weak spots of the W 25.


Concentrated power Chassis with the exhaust side of the W 125 eight-cylinder engine.

Concentrated power: Chassis with the exhaust side of the W 125 eight-cylinder engine.


Some innovative ideas.

The lessons learned here enabled Uhlenhaut and his team to implement some innovative ideas in the W 125 series. Its heart was the further developed eight-cylinder inline engine which, in September 1937, reached the 592 hp mark; later, the team even managed to achieve a top performance of 646 hp. This output was teased out of the engine’s 5,660 cc displacement – as previously at an engine speed of 5,800 rpm. For the first time, the carburetors supplied the final fuel mixture to the downstream compressor. This powertrain model is embedded in a rigid oval frame with four cross-members. The front wheels are suspended on double wishbones and coil springs, whilst the rear uses a De Dion dual joint axle with longitudinal torsion bars and hydraulic dampers.


1937: a strong piece of kit.

Such elements served as a powerful source of inspiration for the series production models of the brand, which later implemented these. Equally new and greatly future-oriented was the wondrous variability with which the W 125 could be set up for the respective race track – for example with up to eight possible transmission ratios and various fuel-air mixtures. After the first test drives in the spring, the vehicle met with the approval of superstar Rudolf Caracciola, who called it “a wonder of power and roadholding”.


He was right: two triple and three double victories serve to underline the superiority of Uhlenhaut’s concept. And at the end of the 1937 season, Caracciola from Rhineland-Palatinate was crowned with the European Champion’s title for the second time since 1935.


Pescara, 15.08.1938: Rudolf Caracciola won the Coppa Acerbo and attained his first season victory.

Becoming a think-tank.

With new Grand Prix regulations for the years 1938 to 1940, the motorsport authorities in Paris again attempted some damage limitation. The displacement for the elite sport was cut back to 3 litres, or 4.5 litres in the case of vehicles without a compressor – a reduction of around 50 per cent for Mercedes-Benz.

The racing department in Untertürkheim, which was still competing on many fronts, definitively became a think-tank. Concepts with front- and rear-mounted engines with eight, twelve and even 24 cylinders were repeatedly drafted and discarded. Even two suggestions from Ferdinand Porsche and an injection engine were discussed. Finally, the team decided upon a V12 initially charged using two Roots-type blowers, before these were superseded in 1939 by a two-stage compressor. Employee Albert Heeß was the man behind it. He created a technological masterpiece with a cylinder bank angle of 60 degrees, two overhead camshafts each, four-valve cylinder heads and an auxiliary carburettor that cut in at high engine speeds.

1938: The magic dozen.

But the approximately 250 kg power unit developed a real need for lubrication and was thirsty for the chemical cocktail upon which it fed – in fact, it consumed up to 180 litres per 100 kilometres. Its performance figures were gently increased from 430 to 468 hp at 8,000 rpm and, for the first time in a racing car of the brand, power was transferred to the rear axle via a five-speed transmission. The chassis layout largely corresponded to that of the predecessor W 125 series, with an additional saddle tank in front of the cockpit. The driver sits low in uncomfortable proximity to the propeller shaft on his left, the position of which was made possible by the slightly diagonal position of the V12.


With a third place in Monza, Rudolf Caracciola brought home his third European championship victory. In the three remaining races, he was first across the line once and came second twice. During training for the 1938 German Grand Prix, Hermann Lang clocked up a time of 9:54.1 minutes and was thus a mere two seconds slower than in the previous year, before going on to drive the lap nine seconds faster in 1939. The last Grand Prix before the war put a hold on motorsport was held in Switzerland.


Hand luggage Mechanics from the racing department carry a lightweight streamlined body.

Hand luggage: Mechanics from the racing department carry a lightweight streamlined body.


The king among racing cars.

“From the first day onwards, I had the unmistakeable feeling that I was sitting in the perfect car – the car of which a driver dreams for his entire life,” is what top Mercedes driver in 1954 and 1955, Juan Manuel Fangio, later wrote about it.

The W 196 R is indeed the king among racing cars in the dawning 2.5-litre era. Argentinian-born Fangio’s score sheet included nine victories and the quickest laps, as well as eight pole positions in the twelve Grand Prix races in which he took part since the French Grand Prix in 1954, plus the two championship titles in 1954 and 1955 – now that’s what you call domination.


1954: A born winner.

What made the car so irresistible in a field full of Italian racing red was its light and finely structured tubular frame. The vehicle featured an unusual, innovative suspension with torsion bars and a single-link swing axle at the rear instead of the traditional De Dion architecture. The racing car’s potent six-cylinder inline engine used desmodromic valve control and direct injection, developed in collaboration with partner firm Bosch. It is mounted in the vehicle’s frame at an angle of 53 degrees to the right (a “slant engine” in automotive jargon) which allows the vehicle’s front surface area to be reduced and its centre of gravity to be kept low.


In Reims on 4 July 1954, it made its début with full panelling, whilst four weeks and two Grand Prix races later, it showed up at the Nürburgring as a much more agile version featuring open wheels and bearing – albeit incorrectly – the designation “Monoposto”. The two body variants can be swiftly interchanged. The key personnel behind this successful model were among the finest in pre-war times: Professor Fritz Nallinger headed up the project, while Rudolf Uhlenhaut was both the head of the technological aspects and a test driver. Alfred Neubauer was the racing director. However, their respective levels of influence had changed: the “big one”, as Neubauer was called behind his back, served merely as a popular figurehead without any noteworthy decision-making authority – but he wasn’t aware of that.


Spielberg, 22.06.2014 A pit stop for Lewis Hamilton at the Austrian Grand Prix

Spielberg, 22.06.2014: A pit stop for Lewis Hamilton at the Austrian Grand Prix.


The engine is no more, long live the Power Unit.

From 2014, Formula 1 caused a radical rethink – a 1.6-litre V6 engine, supported by turbocharging and recuperation of kinetic and thermal energy. Even the word engine itself, as we’d all known it since the times of Gottlieb Daimler and Carl Benz, hung in the balance.

The engine is no more. Long live the Power Unit – the PU. The formula here is PU = ICE + TC + MGU-K + MGU-H + ES + CE. ICE stands for the Internal Combustion Engine, which is assisted by the Turbocharger, two electrical components called the Motor Generation Unit – Kinetic and Motor Generation Unit – Heat, as well as the Energy Store and the electronic monitoring system, or Control Electronics. The engineers have eked out around 600 hp from the ICE and TC combination alone. Add to that up to 161 hp achieved through the MGU-K, and you’re left with a total of around 760 hp – a trend that is still on the increase.


2014: Successful integration.

This sounds complicated – and it is. Much more complicated, in fact. The complex heart of the silver-grey hybrid racer has constantly proved reliable. In a matter-of-fact way, power guru Andy Cowell also adds, “We did our homework better than the others.” The same is true of both the monocoque – a 55 kg structure of carbon fibre and composite weaves – and the aerodynamics. In fact, that’s putting it mildly: perfection is always the aim. The task at hand here is to turn the pieces of the F1 W05 jigsaw puzzle into a sort of living organism. Everything communicates with everything else – as can also be seen at the three locations Stuttgart, Brackley (where the focal point is the chassis) and Brixworth (with a focus on the PU).

Cowell: “The project groups grew as part of a highly integrative system and merged to become a team. Each component was tailor-made, and bit by bit they were all assigned their ideal positions.” And that’s also how, in the three subsequent years, the Formula 1 team became Formula Mercedes AMG Petronas F1. The two disparate drivers Lewis Hamilton and Nico Rosberg pretty much battled the drivers’ titles out among themselves, while the Team World Championship titles were somehow self-evident. Hamilton led the field twice in these tense duels. The third time around, Rosberg turned the tables – and subsequently announced his retirement from the discipline.