1938/1939/1947: Napier-Railton driven by John Cobb
Twin 12 cyl. Napier Lion Aero
Bore x Stroke:
139.7 x 130.2 mm
2500 bhp (approx)
3 Tons (approx)
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.
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.
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 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 tyres.
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
aluminium 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 tyre 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.