The 1955 24 Hours of Le Mans was the 23rd 24 Hours of Le Mans and took place on 11 and 12 June 1955 on Circuit de la Sarthe. It was also the fourth round of the F.I.A. World Sports Car Championship. During the race, Pierre Levegh crashed into a crowd of spectators, killing 84 (including himself) and injuring 120 in the deadliest accident in motor racing history. Regulations The Automobile Club de l'Ouest (ACO) again lifted the replenishment window (just changed the year before) of fuel, oil and water from 30 to 32 laps (just over 430 km), but by the same token, the maximum fuel allowance for all cars was increased to 200 litres for the race. On the track, road improvements continued with the whole back section, from Tertre Rouge around to Maison Blanche resurfaced. Entries A total of 87 racing cars were registered for this event, of which 70 arrived for practice, to qualify for the 60 places on the starting grid, and included 15 factory teams. The battle between Coventry and Maranello of the previous year was joined by Mercedes-Benz, fresh from a triumphant debut in the Mille Miglia with their new 300SLR, along with dark horses Cunningham, Aston Martin and Maserati, all with new 3-litre cars, as well as Talbot, Gordini, Cooper, and Austin-Healey. It led observers to anticipate a great contest. Title-holders Ferrari arrived with the new 735 LM, powered by a straight-six engine derived from the previous year's Formula 1 car (and stepping away from the usual 12-cylinder Ferrari engines) producing a . The works team mixed its current F1 drivers along with new talent: Eugenio Castellotti with Paolo Marzotto, Maurice Trintignant with Harry Schell and Umberto Maglioli drove with Phil Hill. Maglioli and Hill had been Ferrari rivals in the previous Carrera Panamericana. There were also two 3-litre 750 Monzas run by French private entries. Having conquered Formula 1, Mercedes-Benz had now turned its attention to sports car racing. Their 300SLRs were rated by many experts as the best sports cars in the world. The fuel-injected 3-litre straight-8 was the most advanced of the entire field, producing . The inboard drum brakes, however, were only questionably adequate for the heavier chassis, facing the tough braking demands of Le Mans. To compensate, a hand-operated air brake was added to the rear deck for high speed braking. Team manager Alfred Neubauer, in a