1938/1939/1947: Napier-Railton driven by John Cobb

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Napier Railton

United Kingdom
Twin 12 cyl. Napier Lion Aero
Bore x Stroke:
139.7 x 130.2 mm
47,872 cc
2500 bhp (approx)
3 Tons (approx)
Top Speed:

350.20/369.70/394.20 mph

Napier Railton

Burly John Cobb, City man and Brooklands lap-record holder, approached the problem in quite another way when he entered the fray that was the World Land Speed Record.

With the help of close friend Reid Railton, who had designed record-breakers for Sir Malcolm Campbell, Cobb wanted naturally enough to find all the power that he could muster, but have that power installed in a much lighter chassis.

Railton's answer was the “Railton Special”, a car which weighed only three tons, yet disposed of more than 2500 horsepower.

Cobb started preparing the car in 1935, but it was three years before he was ready to go to the Bonneville Salt Flats, about 125 miles from Salt Lake City, for his attempt.

An added problem on the great salt lake, which is what remains of a prehistoric lake of about 19,000 square miles area, is that it stands at 4,000 feet above sea level, imposing a consequent loss of power on the engines.

The lake offers a straight run of about 13 miles, which is not excessive for acceleration, the timed run, and braking from the speeds which Cobb was aiming at, namely 400 miles per hour, a speed he very nearly achieved.

The temperature on the salt lake runs up to more than 110 degrees Fahrenheit in the shade, if any can be found, and this too imposed problems for adequate cooling of engine and tires.

But Cobb and Railton overcame all these problems sufficiently well for Cobb to be the fastest man on wheels three times before his death. Cobb made his first run in September 1938, when Eyston's record stood at 345.50 mph and Cobb had never driven faster than 170 mph at Brooklands.

A truck was used to push-start the Railton on September 15, and Cobb climbed through the truck to avoid stepping on the slim four-hundredweight aluminum shell and dropped into his cockpit after walking over planks placed on the hull. He became the first man to drive at more than 350 mph. After pushing the record up twice to a final 394.20 in 1947 he died, like Segrave, attempting to add the water speed record to his laurels.

Cobb's car would go on to hold the land speed record until 1963, a remarkable 16 year run, and remains to this day a fitting tribute to both designer and driver. Reid Railton used many unorthodox methods to achieve his result. He started with an S-shaped backbone chassis, and used two second-hand 1928 Napier Lion aero engines from a motor boat, but set them at an angle, one driving the front wheels and the other the rear wheels.

Railton pared weight from the supercharged Lion engines until they scaled only 1120 lb each yet still delivered a total 2500 horsepower. There were neither flywheels nor clutches, and Cobb sat up front ahead of the power plants, as in a modern racing car.

The special lightweight body shell was made in one piece and had to be taken off for re-fuelling and tire changes between the two runs necessary for the record.

The whole body, less its undershield, could be lifted off by six men. Cooling was also by a novel method, no radiator being used, but an ice-tank which was repacked between runs. The melted ice was also used to take heat away from the drum brakes, before being ejected from the non-circulatory system. Wheelbase was 13 ft 6 in, and the car 28 ft 8 in long, 8 ft wide and only 4 ft 3 in high.

Also See:

Land Speed Record Drivers
Herbert Austin LSR Attempt
History Of The Land Speed Record
Unique Cars and Parts USA - The Ultimate Classic Car Resource