A Great Day for a Great Car
Launching the magnificent Mercedes-Benz 300 of 1951
Part 1 of a new series
Article Graham Robson
Images Daimer Archives, Maurice Liang
Mercedes-Benz and its predecessor companies have built motorized vehicles for more than 120 years. Repeatedly during that long span of time, the firm managed to pull off improbable feats of design and production and reach seemingly impossible goals, amazing observers everywhere. In this first installment of a new series revisiting some of those historic accomplishments, let us recount how the superb Mercedes-Benz 300 sedan rose out of the rubble of war to become a splendid postwar flagship for a revitalized company.
A ruined country
It has often been said that the real postwar-WWII miracle that took place in Stuttgart was that Mercedes-Benz Cars survived the conflict at all. Be that as it may, even after six years of backbreaking reconstruction, very few onlookers could have expected the company to produce an all-new model, let alone such a beautifully engineered and built machine that would help redefine postwar automotive luxury (see The Star, March-April 2019).
In my first book on the history of Mercedes-Benz, The Magnificent Mercedes-Benz, published in 1981, I summarized what the firm attained after 1945.
“Things were so bad and the destruction was so complete, that Daimler-Benz directors were obliged to issue a terse statement to the effect that: ‘… for all practical purposes, Daimler-Benz has ceased to exist. …’; they were not exaggerating. At least 70 percent of the old Stuttgart-Untertürkheim factory had been destroyed, along with 80 percent of the truck works at Gaggenau and no less than 85 percent of the vast Sindelfingen factory just outside the city.
“Clearly, at this stage, there was no possibility of designing, tooling-up and manufacturing a series of new models – not even one new model. In Germany, there was not only great destruction to be swept aside, but there was financial chaos.”
Not only had much of the country’s car-making capacity been destroyed by Allied bombing, but the postwar partition of the defeated nation would lead to the birth of East and West Germany, marooning many businesses behind what, in 1946, Winston Churchill would famously call the “Iron Curtain.”
Until 1939, of course, Mercedes-Benz had produced the best, the fastest and the most prestigious of all German road cars, a feat that BMW had attempted, but failed, to match. Several other vehicle manufacturers – including Borgward and Hansa – squabbled over the middle ground, while Ford and Opel built modest machines for the lower classes, DKW produced lots of two-stroke machines, and Adolf Hitler’s Volkswagen – the heavily promoted “People’s Car” program – was about to bear fruit.
From 1945, however, things were very different; BMW was lost behind the Iron Curtain and, apart from Borgward’s efforts to produce a viable middle-class machine, there was nothing on the new-car market to meet basic transportation needs. As far as a prestige-machine was concerned, affluent customers finally had some money to spend – but there were no luxury cars in the showrooms for them to buy.
Once and future dream
In 1946, as a first giant step back from the brink, Mercedes-Benz managed to revive production of the prewar 170V (W136) sedan (see The Star, November-December 2018), followed by the 170D, with its 1.7-liter diesel engine. Annual production of 170Vs rose to 17,417 in 1949 and to 33,906 in 1950. Demand for new cars in Germany and all of Europe was buoyant. Soon, Mercedes-Benz was profitable again. This earliest postwar period represented more than simply a means to re-establish the Stuttgart firm as a viable concern able to earn hard capital. By 1955 – when the 170 range finally bowed out for the last time – an impressive 153,475 of all models had been built, a clear measure of public appetite.
At the same time, foresighted senior management at Mercedes-Benz perceived an opportunity at the top end of the expanding automobile market. In the 1930s, the firm had produced the best of all German vehicles, ranging from high-quality mid-size sedans to phenomenal high-performance sports machines. Mercedes-Benz had once covered every automotive base; perhaps it was time to dream of doing it again?
Birth of the 300
In particular, the company’s chief engineer, Dr. Fritz Nallinger (see The Star, May-June 2018), was envisioning an all-new luxury model. No one else in the firm was as qualified as Nallinger for this role. His father, Friedrich Nallinger, had become technical director of Benz in 1912; fledgling engineer Fritz had joined the firm in 1922. Rising up the ranks, in the 1930s he was responsible for testing and development at Mercedes-Benz.
In 1948, after detailed discussions with other board members, Nallinger formally embarked on the company’s first postwar clean-sheet project – the W186, or the 300, as we know it today. Along the way, the vehicle’s chassis, originally intended for a four-door sedan, was enlisted to carry the stylish coupe, cabriolet and roadster – and bespoke long-wheelbase versions as well. Although turning the dream of the W186 into showroom reality would be risky – and costly – it proved to be worthwhile.
Nallinger and his engineering team knew they were designing for the future – a long-term future they hoped would allow the models’ production for up to 10 years – but no attempt was made to invent a radical layout for the new car. At first glance, there seemed to be remarkable parallels between the rolling chassis of the new W186 and that of the aging 170V. In truth, there was not a single component shared between the two vehicles.
However, Nallinger had carefully studied the firm’s earlier machines. In 1931, nearly 20 years earlier – when Hans Nibel had been technical director – Mercedes-Benz had introduced its inaugural modern chassis, the first-generation 170. Innovative for its period, the 170 had independent front and rear suspension, as well as a single-overhead-camshaft engine, adapted from those already powering Ferdinand Porsche’s ultra-sporting machines of the mid-1920s. Then in 1935, the 170V appeared – the very car that in 1946 helped Mercedes-Benz haul itself up by its postwar bootstraps – designed around a novel tubular-section backbone chassis and riding on all-independent suspension.
In the prewar era, Nallinger might have been directed to build his new vehicle around the bones of an existing model, but when work on the 300 began in 1948, there was no such consideration. Not only was the engineering team cleared to build an all-new machine, there was no legacy in terms of engines, transmissions, and tooling – nothing had survived the war – to help implement their goal. Certainly, the devastating bombing of Stuttgart in 1944-1945 was partly responsible for this clean-sheet approach, but the brave decision to start afresh was always paramount.
Design and development
Not that creating such a ground-breaking luxury vehicle would be easy. Investing in a new, 120-inch-wheelbase version of the proven oval-tube backbone chassis with independent suspension all around – a swing-axle with coil springs in the rear and an improved front coil-spring arrangement (rather than the transverse-leaf front layout of the 170V) – was a straightforward decision. However, it was the colossal expense of developing, testing, tooling and installing the massive machinery needed to produce large four-door-sedan body shells, an all-new 6-cylinder engine – and the up-to-date transmissions to match – that would cause sleepless nights for fretful company accountants lodged in makeshift postwar offices in Untertürkheim.
From the earliest days, the development team was determined to make the all-new, top-of-the-line machine as sophisticated as possible. If this increased production costs, so be it. Such fearless ambition so soon after such a devastating conflict was both brave and notable. Novel components abounded: The 300’s front suspension anti-roll bar design was a first for Mercedes-Benz. A hypoid-bevel rear axle – new in Germany, though already proven effective in models produced in the United States and the United Kingdom – also added to the investment cost, as did the creation of an ingenious ride-selection system for the rear suspension. As implemented, a driver-activated switch on the dashboard operated an electric servomotor, triggering a pair of auxiliary torsion bars to stiffen the rear suspension. This feature offered a wider range of suspension compliance, augmenting the ultra-soft ride traditionally provided by such a luxurious automobile.
The big sedan was an appealing mix of old-style and modern luxury. Its spacious cabin offered sufficient headroom that Konrad Adenauer, Germany’s first federal chancellor, could wear his top hat in the car, leading to the model’s enduring nickname, the “Adenauer.” Mercedes-Benz had cleverly integrated some of the latest automotive trends from Detroit: The interior’s modern layout of dials, switches and control gear was surrounded by the traditional luxury of polished wood. The orthopedically devised front seats were designed to recline. Such attention to detail underscored the company’s intention to place the majestic 300 firmly at the pinnacle of European motoring in the 1950s.
Mechanical masterpiece
Even so, for engineering experts who surveyed the big sedan when it was first revealed, one feature stood above all other achievements: The all-new 6-cylinder M186 engine was quickly recognized as a mechanical masterpiece. Nallinger’s team put everything they knew into the uncompromising design of the M186 (thoroughly analyzed in the The Star, January-February 2012). At the time, the development engineers could not possibly have known that this splendid 2,996cc power unit was so advanced and so superior that it would remain in production for 16 years – until 1967. The M186 powerplant would eventually adopt fuel injection, and its touring car tune would gradually rise from 115 brake horsepower to 170 brake horsepower. In its famous 300SL sports-car guise, the engine would reach a peak output of 250 SAE horsepower. This near-faultless engine also propelled the 300SL to famous victories in the 1952 24 Hours of Le Mans endurance classic and the grueling Carrera Panamericana road race (see The Star, May-June 2019).
The engine’s mechanical details reveal just how much thought went into its layout – and how invaluable the company’s past engineering successes had proved when starting over again after 1945. The M186 utilized a cast-iron block mated to a light-alloy cylinder head with a chain-driven single overhead camshaft. The head was joined to the block at an angle of 30 degrees, requiring the spark plugs to be placed in the block rather than in the head itself. This configuration proved to be prescient: When the time came to apply fuel injection to the M186, the injection nozzle could be installed exactly where the spark-plug orifice had been.
At the new sedan’s first public appearance at the IAA International Motor Show taking place in Frankfurt April 19, 1951 – just three years after the dream initially took shape in Untertürkheim – a preproduction example received a rapturous reception from the press and public alike. With a top speed nudging 100 miles per hour, the sleek 300 was the fastest European luxury sedan then available. For the enthralled crowds, the glamorous new machine symbolized both postwar economic resurgence and the emergence of the young Federal Republic of Germany onto the international stage.
Even though the new car was not yet on sale, early examples were made available for evaluation by a select few. After completing a stint in one of these machines, road-test editors for Britain’s venerable Autocar magazine were lavish in their praise:
“The Type 300 Mercedes was evolved after a critical analysis of the American cars with which it must compete. After driving the car for some miles at high speed, both on autobahnen and on winding country roads... The Autocar felt that the Mercedes offers an extraordinary combination of top-class stability and superb driving comfort.”
Once customer sales began early 1952, the 300 quickly leapt to the top of the automotive-prestige tables. Attractive cabriolet, coupe and roadster body styles were built, along with specialized long-wheelbase versions. Over time, the M186 engine received regular boosts to its power and specifications. Conceived in the uncertain days of the late 1940s, the 300 swiftly found favor with royalty, presidents – and even the Pope. The new machine single-handedly restored the firm’s prewar reputation for creating vehicles able to harness superb automotive engineering in service to the highest level of luxury motoring. In every way, the launch of the Mercedes-Benz 300 on that April day in 1951 truly was a great day for a great car.
MERCEDES-BENZ 300 PRODUCTION TOTALS 1951-1962
YEARS MODEL NUMBER BUILT
1951-1954 300 Sedan • Cabriolet 4,927
1951-1955 300S Coupe • Cabriolet • Roadster 560
1954-1955 300b Sedan • Cabriolet 1,878
1955-1957 300c Sedan • Cabriolet 1,483
1955-1958 300Sc Coupe • Cabriolet • Roadster 200
1957-1962 300d Sedan • Cabriolet 3,142
TOTAL PRODUCED 12,190
A partial view of ruined main assembly hall, Mercedes-Benz Sindelfingen plant, 1944. The long-established Untertürkheim factory complex was also all but destroyed in 1944-1945.
By 1950, thousands of 170V and 170S vehicles poured from the rebuilt Sindelfingen plant.
Draftsmen at work on 300 plans, Sindelfingen plant.
Presentation model of a 300 sedan, 1952.
The X-oval tube frame of a W186 300.
No expense was spared in the development of this company flagship: Coil springs and independent suspension provided improved handling and comfort; the heavily bolstered, adjustable seating offered lumbar support.
Metal worker filing the support for chrome side trim; the superb quality of the 300 required hours of hand finishing by skilled labor.
The 300 brought the two-spoke steering wheel with chromed horn ring and a modern instrument cluster with central speedometer to Mercedes-Benz passenger cars.
Masterpiece: 2,996cc 6-cylinder M186 engine.
First seen in April 1951, the Mercedes-Benz 300 W186 was a sensation at the IAA International Motor Show, Frankfurt.
Suddenly, Mercedes-Benz was back in the top ranks of luxury carmakers, as reflected in this poster of the 300 in the elegant setting of high society.
The 300 sedan soon bred long wheelbase and roadster, as well as coupe and cabriolet versions. A redesigned heir, the fuel-injected W189 300d, appeared in 1957 and was built until 1962.
A line of W186s receives finishing details, Sindelfingen plant, 1953.