From 246 to 272 mph — the problems involved

(This is the Golden Jubilee year of the Railton car, which we have already commemorated with a long article on this Anglo-American make in the April 1983 issue. From time to time Motor Sport has published intimate details of various pre-war Land Speed Record cars, as representing the highest pinnacles of speed and automotive technology in their day. This account of the problems Reid A Railton (1895-1977) experienced and overcame in making Sir Malcolm Campbell’s Campbell Special “Blue Bird” increase its speed by 24 mph between 1930 and 1933 adds to the unique LSR story and serves as a further tribute to a very talented engineer. It also has some significance while Richard Noble is trying to establish a new LSR of over 630 mph for Britain. — Ed.)

Malcolm Campbell had the Napier-Campbell car built after he was unable to go any faster than 150 mph in the aged V12 18.3-litre Sunbeam. It dated back to 1926/7, the design work of J Mania and Amherst Villiers. (The table outlines its stages of development). From 1930, having progressively held his own at the dangerous and technically-exacting LSR game, Campbell called in Reid A Railton to help with further development of his now-famous “Blue Bird” record-breaker. He was out to better Segrave’s 231 mph with the Napier-powered “Golden Arrow”. To this end, the former 925 hp Napier aero engine was replaced by a new 1,450 hp Schneider Trophy-type supercharged Napier engine. Here it must be emphasised that Railton would have preferred to have built an entirely new car round this engine but that time and money were against this. Indeed, even on its final form, Railton regarded “Blue Bird” as very much a compromise, even in its eventual 300 mph guise. His chance to design an entirely new LSR car did not come until John Cobb asked for one, the result being the remarkable 2,500 hp twin-Napier Lion-engined, four-wheel-drive Railton that eventually exceeded 400 mph on one run, in 1947. The brave new conception of this car will forever remain a tribute to Railton’s engineering genius. What we are about to reveal is how he coped with the more detailed problems consequent on serving the money-cautious Campbell, enabling that driver to achieve his continuing LSR ambitions, almost, as it were, on a shoestring.

Campbell had spent considerably less than £10,000 on the creation of his first proper LSR car, the Napier-Carnpbell, and was reluctant to spend much on the modifications he desired Railton to carry out for him. Added to which, there was less than a year in which to do this, to meet Campbell’s deadline. Even so, all that Railton retained of the existing “Blue Bird” was the front axle, brake gear, steering gear and the side-members. To reduce drag he off-set the propshaft to the near-side, enabling the driver to sit lower. To accommodate the new engine within the existing wheelbase, a multi-disc clutch inside the flywheel was used, driving to a normal three-speed gearbox and torque-tube final drive. Alarmists thought the enormous torque taken through the road springs would be felt by the driver, but as these springs deflected under full torque by only 3/4 in, this was not the case, or was it with the car in later, far-more-powerful form. Railton was also assured that, as he had taken the driving thrust to a point not on the car’s centre-line, “Blue Bird” would pull badly to the right. Campbell was also gravely warned of this, but it was a complete fallacy, of which it was very difficult to convince many sensation-mongers. Campbell never felt any adverse affects from torque reaction when opening and closing the throttle, and Railton had built sufficient stiffness into the rear end of the frame to combat the lateral bending load from the off-set torque-tube.

The body shape had to be altered to cope with a seat set four inches to the right of centre, but any idea of discarding the radiator for ice or other sorts of evaporative cooling were abandoned because of the shortage of time and money for experimenting, in spite of Irving having ice-cooled the Napier engine in the “Golden Arrow”. Railton was convinced that a nose-mounted radiator of the deep honeycomb kind used on high-speed aeroplanes would add very little to the total drag and after discarding one outrigged some feet ahead of the car’s nose, because of header-tank bulk, another set some 10 in in front was used, with a false nose extending to within about three inches of the main nose fairing. In fact, although wind-tunnel checks on a model indicated that the record was theirs by a good margin, lack of time resulted in a shape not even intended by Railton. He used a big fin on the tail. The body was of aluminium panels over a tubular framework, such as would be understood by a normal coachbuilder, in this case Gurney Nutting & Co. This was, in a sense, another time-saving expedient, although the weight involved did not matter, as it reduced the ballast needed for wheel adhesion.

Campbell took this slightly revised car out to Daytona in January 1931 and set the LSR to 245.7 mph over the two-way mile, for which he was Knighted. A spring catch on the gear lever overcame a tendency for the top-gear dogs to jump out under load, one set of tyres sufficed for a non-stop bid, and after initial shock-absorber adjustments “Blue Bird” handled well. However, the beach was in poor condition and Campbell decided he could go faster. That summer he commissioned Railton to make what modifications were deemed necessary, but very little was done apart from installing a spare engine so that the other could be overhauled (after a minimal mileage!) and reducing the radiator block in area, as the water temperature had not risen above 60 deg C, on the previous runs, the shape of the cowling round it being improved at the same time. Campbell tried again in February 1932, having waited for the beach to improve, and achieved 267.5 mph with the wind behind him, 241.8 mph against the 15/20 mph breeze, a new LSR of 253.9 mph over the two-way mile. In fact Railton thought his better effort was the 10-kilo record at 238 mph, describing this as “the best the car and driver had ever achieved”.

Back in England, Railton received a telephone call from Campbell, the ever-restless “Speed King”, asking him to call in. When Railton did so, he was jolted out of any complacency he felt over the successful record bids, when Campbell confronted him with installation drawings of the 36.5-litre 3,250 hp Rolls-Royce R-type supercharged V12 racing aero-engine, saying “What about putting this in the old car?” Railton’s feelings, he said, were indescribable!

It was necessary to increase “Blue Bird’s wheelbase by 171/4 in, using two new frame members, during which time the steering gear was modified slightly, as its peculiar layout had induced gyroscopic flick. The road springs and shock-absorbers had to be strengthened to cope with the increased torque and additional ballast. It was the increased torque of the R-R engine, which was almost exactly double that of the Napier engine, that posed many problems. Fortunately, Railton had been generous with transmission dimensions, otherwise the time/money factor would have rendered the latest project impractical. Apart from the axle bevel gears, where former retention of the old back axle for economy had limited their size, nothing much had to be redesigned, and as the new bevels showed pitting on the pitch-line (after two years and some 150 miles!), clearly they were loaded to capacity and would have to be replaced anyway.

Even so, it was a dreadful compromise, carefully calculated by Railton. He had to tell Campbell that as the entire transmission could not be remade, the safety factor depended on the materials being rigidly up to specification and the car never being driven on a bad or doubtful surface. Campbell was prepared to take that chance and Railton, at T&T’s at Brooklands, set about strengthening only the gearbox secondary-shaft, the prop-shaft and the final-drive bevels. However, a completely new clutch was needed and several alteration to the transmission ball and roller bearings. It was at such compromises, when there were unavoidable, that Railton excelled.

The Rolls-Royce engine was taller than the broad-arrow Napier, so Campbell’s seat had to be raised, for him to see round it. Economy dictated using the same body as before, so the cylinder banks were closely cowled in, as had been done so sleekly for the Napier’s three blocks on the “Golden Arrow”. However, Railton was of the opinion that this was a mistake, and that these excrescences and the radiator cowl, with the windscreen behind them, resulted in drag disproportionate to their size. However, with the great power available to him, he was justified in being conservative, when much new ground was being broken elsewhere. After all, the Rolls-Royce R-type engine gave over 1,300 more bhp than the “Golden Arrow” had had, and its record had already been improved on by “Blue Bird”. . . .

Railton may have been aware that Miller in America was thinking in terms of a 180 in wheelbase, 4WD LSR car with a supercharged V24 marine engine said to give 3,000 bhp, and all-enveloping body, Miller finances flopped and it never materialised, however.

For the R-R “Blue Bird” Railton retained the nose radiator, even though due to the large central air-intake duct and the cylinder-head fairing the space behind it was much restricted, eliminating the semi annular duct between its cowl and the nose of the body, a bad arrangement, he admitted. But it was feared that if the radiator was moved forward, its large mass might affect steering. So air was released from it through two large nostrils at the front of the main-engine cowling. Railton spent much time checking how the body shape would affect control of the car, the R-R-engined “Blue Bird” being critical at full throttle even on a good surface, if wheel spin was induced. Clearly, downthrust in this context was to some extent understood; it was calculated as 350lb down on the front axle, 300lb on the rear axle, at 250 mph. On this rough assumption the ballast carried was adjusted.

The R-R engine, from which the propeller shaft and reduction gear had obviously been removed, gave 2,180 bhp at record speed (271 mph), and its propulsive thrust was 3,020 lb at maximum efficiency. Railton calculated the torque required to spin the rear wheels with an axle load of 6,500 lb and 0.75 coefficient of friction between tyre and sand and thought this was higher than would ever obtain. He used a clutch with nine lined driven plates at a pressure of approximately 40 lb / sq in. The pedal pressure was some 70 lb, with a six inch travel. The gearbox ratios were 2.74, 1.55 and 1.0 to 1, with an axle ratio of 1.19 to 1. The engine was cooled with a 434 sq in radiator, having tubes of 320 mm x 10 mm (diameter), capable of absorbing a heat transfer of 48,000 BThU per minute, an increase of 12,000 over the Napier installation. Campbell controlled the car via an accelerator coupled through an Arens control, with interconnected ignition advance. He also had a hand-operated slow-running control. Fuel feed from two tanks, one under and one behind his seat, totalling 28 gallons, was by a gear type pump driven by the timing gears, no hand-pump, as was used in the Napier installation in case of vapour lock, being used. The gearbox used dog-clutches for gear engagement of the constant-mesh pillions, and was easy to use, although if Campbell missed a change his hand “got a nasty kick”.

The suspension deflections of the half-elliptic springs were 1.85 in front, 2.90 in rear, as against 2.85 in and 2.82 in respectively for the Napier-engined “Blue Bird”. The steering ratio was 13 to 1. The brakes had alloy shoes lined with Ferodo, servo-applied, with the vacuum derived from the pressure-side of the supercharger, a non-return valve isolating it when the blower pressure rose above atmospheric. The brake’s thermal problems involved dissipating up to 60,000 BThU per minute of heat. “Blue Bird” had a vvheelbase of 13 ft 8 in, weighed 10,900 lb ready to go (4,400 lb front / 6,500 lb rear), carried 10 gallons of oil and 27 gallons of water and ran on front Dunlop tyres of 35.6 in, rear Dunlop tyres of 37.6 in (diameter). In its design and construction Railton was aided by Ken Taylor and his chief draughtsman, RH Beauchamp; the latter has previously written for Motor Sport.

Campbell took the R-R “Blue Bird” to America again in January 1933 but, warned repeatedly by Railton that with the enormous power and comparatively low margin of adhesion he must wait for a smooth beach, he waited for over three weeks, then decided to go, in spite of low-lying mist and a shell-strewn narrow course. On February 22nd he seta new mean-speed LSR of 272.46 mph for the mile. This time the tyres were changed after each run, being cut by the shells, Control was difficult and visibility in places was less than half-a-mile. But Carnpbell won through; by 1935 he had driven at over 300 mph. On this 1933 occasion the tachometer indicated 4,000 rpm, equal to 370 mph had the back wheels not been spinning.

Shall we now pay our respects to Reid Railton and conclude by wishing Richard Nobel good luck with Thrust 2, if he is still hunting this elusive (standing at over 630 mph) Land Speed Record? — WB.