Racing Car Development

Racing Car Development

CARS designed and built for record-breaking probably undergo more development and changes for less running fime dim any other form of racing car, but if the development is good then the rewards are great. Some r.ord breaking .ry have been built for one successful attempt and then never run again, and a classic example of this .n be seen in the National Motor Museum at B.ulieu. It is the “Golden Arrow”, a car designed by Capt. J. S. Irving for Major Henry Segrave, which took the Land Speed Record in March 1929 at Daytona Beach with a mean speed for a two-way run over the measured mile, of 231.446 m.p.h. The car did one pair of practice runs at 180 m.p.h. and then broke the r.ord and was never run again. It was built specially for the job, did the job superbly and was then put away. Thankfully it was not broken up and today we can admire it as a remarkable pieir of engineering. That other indefatigable record-breaker. Capt. Malcolm Campbell was never content and his record-breaking “Bluebird” underwent continual development in the endless search for more speed. The first specially-built “Bluebird” appeared in 1927, using a Napier Lion arm-cngine and this was to be the basic of five major redesigns over the next eight years. In 1930 Campbell employed the services of a brilliant young engin.r named Reid Railton and his job was to build a new can from the bones of the existing one, retaining the chassis frame, the suspension and the meeting but discarding everything else. The Napier Lion engine was replaced by a newer version that was bigger and supercharged and gave 1450 b.h.p. against the earlier one’s 450 b.h.p. Radios later explain.’ that he would hale preferred to have designed the can from scratch, hut money was limited so he had to use the 1927 chassis frame and as many of the original parts as possible. He did manage to persuade Campbell to invest in the design ifs new 3-speed gearbox. The redesigned “Bluebird” took the Land Speed Record in 1931 at 246.09 m.p.h. and again the following year at 253.97 m.p.h.

Campbell always had new targets arid m 1933 he negotiated the loan of a V12 Rolls-Royce Schneider Trophy engine, giving 2,300 b.h.p. and Railton set about redesigning “Bluebird” to take this new engine. The 361/2-litre V12 engine was installed in the same chassis, in place of the 26.9-fiwe ‘broad-arrow’ 12-cylinder Napier-Lion and the bodywork was reprofiled to suit. As Railton said “We should consider ourselves lobe very lucky in that the present-day racing mm-engine is so admirably shaped for fitting into a motor-car”. This version of “Bluebird”, illustrated th the accompanying photograph (finner), took the remrd at 272.46 m.p.h. at Daytona Beach, in Florida. USA, but now Campbell had his sights on 300 m.p.h. Onne again the ever-inventive Railton applied himself to the tuk and produced another version of “Bluebird”, shown in the lower pholognaph. A totally new all-enveloping bodY mm buil,. WM using the same chassis underneath, but a new front mile was designed and a revolutionary rear-end. Twin rear wheels were used, to combat wheelspin, each pair being driven from its own final bevel drive, with no differential between them. Behind the rear wheels were air brakes in the form of flaps that hinged up, servo-operated through the brake pedal, which operated the normal drum brakes on the wheels. The Rolls-Royce R-type engine was now giving 2,350 b.h.p. and in March 1935 Campbell took the record, again at Daytona Beach, at 267.816 m.p.h. with a best run at 281.03 m.p.h. The long stretch of sand on the Florida coast was no longer suitable for such speeds as were being obtained and Campbell and Railton were confident the ear could attain 300 m.p.h. if a smooth surface could be found. In September 1935 they went to the Bonneville Salt Flats in Utah, USA, and the record was taken again at 301.129 m.p.h., with a

best run of 304.311 m.p.h.

At that point “Bluebird” in her fifth and tual form was laid to rest forever. Today she sits in the Museum of Speed at Daytona Beach, occasionally being taken out into the open air for a parade, bui never run. The publicity blurb that accompanies her in the museum claims a top timed speed at Daytona of 330 m.p.h., but the fastest ever officially recorded on the sands was 281.03 m. p.h .—D.S. I .

FOOTNOTE: I am indebted to Cyril Posthumus for the information on the “Bluebird” development, from his book .LAND SPEED RECORD” published in 1971 by Osprey Publishing Ltd.