The 2015 Solitude Revival and a "Hobel " design Mercedes-Benz 300 SL

Three versions of the Mercedes-Benz 300 SL at a glance: on the left, the Mercedes-Benz 1952 300 SL (W 194 series), next to it the racing car prototype (chassis number W 194 011) developed for the 1953 racing season (this prototype never raced), finally the 1954 series-production car 

Hans Herrmann competing in the French Grand Prix in Reims, 1954.

Mercedes-Benz 300 SL (W 194 series) with chassis number W 194 011. Racing prototype developed for the 1953 racing season. However, this prototype never raced.

A unique gem from the Mercedes-Benz Classic collection will be in the starting line-up at Solitude Revival 2015: the Mercedes-Benz 300 SL with chassis end number 00011/53, affectionately known as the "Hobel" ("carpenter's plane") on account of its striking front-end design. The event will take place from 17 to 19 July 2015 and celebrates the former race circuit just outside Stuttgart and the motorsport successes attained there.

Stuttgart. – The legendary Solitude Ring was one of Germany's leading circuits for car and motorcycle competitions. Races were held here until 1965, including Formula 1 meetings in the 1960s. "The Solitude", as the winding, roller-coaster triangular circuit is called, citing the palace of the same name which is situated nearby, is also of major significance to Mercedes-Benz, whose best racing cars and drivers were already competing here before the Second World War. Alfred Neubauer appeared here for the first time in his capacity as race manager in 1926. And in the 1950s the "Solitude" was used for testing racing cars and training drivers.

"The Solitude Revival commemorates a golden age of motorsport in Stuttgart. This year, Mercedes-Benz Classic is celebrating the incredibly successful 1955 season – in which the 300 SL played an instrumental role", says Michael Bock, head of Mercedes-Benz Classic and the Customer Center. "As an automotive brand which is particularly committed to upholding our classic car heritage, we can well imagine stepping up our involvement at the next Solitude Revival in 2017".

In the wake of the Second World War, Mercedes-Benz achieved a highly successful return to international motorsport in 1952 with the 300 SL racing sports car (W 194), ten of which were built in all. Its greatest triumphs included double victories in the Le Mans 24-hour race and the Carrera Panamericana. Keen to continue this excellent showing in 1953, the management board decided to develop an improved vehicle for the new motorsport season. The prototype, allocated chassis end number 00011/53, featured a host of performance-enhancing improvements compared with the original 300 SL racing sports car. With the new direct petrol injection system, for example, the engine now had an output of 215 hp (158 kW) - a good 40 hp (29 kW) more than the original version with carburettor. In addition, the transmission was now installed in a transaxle configuration, a single-joint swing axle was used for the first time, the cooling air ducting was modified, the overall weight of the vehicle was lowered and the chassis was revised. The engineers also reduced the frontal area. This modified front-end design earned the vehicle the nickname "Hobel" in German, which translates as "carpenter's plane". The vehicle was completed and ready to compete at the beginning of 1953. But then the company decided to resume Grand Prix sport as of 1954 and to field a totally new racing car in Formula 1. This ambition took precedence over all other motorsport activities, as a result of which its plans to take part in racing in 1953 were abandoned and the 300 SL was never raced in any competitions. Instead, it provided important findings for the new Formula 1 racing car - the W 196. Above all, however, its injection engine made it an important predecessor of the famous 300 SL "Gullwing" series production sports car  (W 198), which was built from 1954.

The "Hobel" on the Solitude – and Hans Herrmann in brilliant form

12 October 1953. Mercedes-Benz reserved a whole day on the Solitude Ring for test drives, as well as to give the drivers an opportunity to put in some training for the 1954 season. As the route ran along normal public roads, it was cordoned off by 150 police officers. Two 300 SL models were available: a racing sports car from the 1952 season and the vehicle with chassis end number 00011/53. The starting and finishing line was at Glemseck Corner.Race manager Alfred Neubauer had everything organised just like on a race day: tyres, fuel drums, signal flags and timing facilities were in place, mechanics and engineers were present, as were photographers and medics. A perfect set-up for a training day.

The fastest lap time was clocked up by the youngest driver: Hans Herrmann finished the 11.7-kilometre course in 4 minutes and 52 seconds, outclassing considerably more experienced drivers in the process: Karl Kling (5:17 minutes), Hermann Lang (5:10 minutes), Fritz Rieß (5:07 minutes) and technical test manager Rudolf Uhlenhaut (5:03 minutes). "Our up-and-coming young driver Hans Herrmann put in a surprising performance, being the only one to finish in under five minutes and breaking the official lap record held to date by motorcyclist Kavanagh", Neubauer noted in his report – and he duly signed up the talented young driver for the 1954 season on the strength of this extraordinary high-speed feat.

Hans Herrmann maintains close ties with Mercedes-Benz cars to this day. As one of Mercedes-Benz Classic's ambassadors he is frequently to be seen behind the wheel of historical racing cars at renowned events.

Solitude Revival 2015

Mercedes-Benz Classic will be moving the 300 SL around the legendary circuit at the Solitude Revival 2015 on Saturday, 18 July. On Friday (17 July) and Sunday (19 July) the vehicle will be on display at the drivers' paddock, offering ample opportunity to admire it close-up.

The Solitude Revival was staged for the first time in 2008.The next meeting took place three years later, since when the event has been held every two years - on the authentic circuit, just as it existed 50 years ago. The sole requirement for participants is that the vehicles have to have been built prior to 31 December 1975. This criterion and the presence of outstanding racing cars and racing drivers guarantee an extraordinary museum on wheels at the event.The highlight is a race covering 12 laps and a total of 140 kilometres.A comprehensive programme of accompanying attractions rounds off the event.

The 18th of July is a notable date for fans this year, as it was on this day precisely 50 years ago that the Solitude Grand Prix made racing history, with both the world championship races in all six motorcycle classes and a Formula 2 race all taking place on the same day.

Mercedes-Benz 300 SL racing prototype (W 194, 1953)

1953 saw the launch of a fully revised version of the 300 SL racing sports car which had raced to one victory after another in 1952. Thanks to direct petrol injection, the new racing sports car for the 1953 season had an output of 215 hp (158 kW) - a good 40 hp (29 kW) more than its predecessor. Track width and wheelbase were reduced and the front end was modified, resulting in lower drag. Other highlights were the single-joint swing axle that was used for the first time and the transmission flange-mounted on the differential in transaxle configuration – measures which resulted in better-balanced axle load distribution and excellent handling. Due to the angular front end of the newly designed body, the unique innovative gem acquired the internal nickname "Hobel", which translates as "carpenter's plane". While it was never entered in a competitive race because the entry into Formula 1 which was planned for 1954 tied up all the available capacities, it represented an important stepping stone on the way to the 300 SL "Gullwing" series production sports car.The "Hobel" has remained in the company's possession ever since 1952.

Technical data - Mercedes-Benz 300 SL racing prototype (W 194)

Cylinders: 6/in-line
Displacement: 2996 cubic centimetres
Output: 158 kW (215 hp)
Top speed: 250 km/h