SPEED RECORDS

Evening Post, Volume CVII, Issue 67, 22 March 1929, Page 18

SPEED RECORDS

BRITAIN'S AMBITION

THE MISSION Ol' 1 SEGKAYE

The story of the building of the "Golden Arrow" and tho speed-boat "Miss England," with which Major Segrave has captured the world's record speed on land and hopes to gain that on water, is contained in a book produced under the title of "Progress." ** The man behind tho cur was Mr. 0. J. S. Piper, who, entirely unconnected with the motor trade, associated himoslf with tho venture from no other motive than sportsmanship, and, above all else, an ambition to see the Wakofield Trophy returned to Britain.

The book makes clear-that the car was designed with tho aim of being the first vehicle in the world to accomplish a speed of four miles a minute.

"In the most literal sense," states tho book, "the car was designed around the driver. He was accordingly placed in a dummy seat of the smallest possible dimensions and a silhouette taken of his cross-sectional area. Around the 'figure target' was built a rough wooden 'mock-up' of that section of the car. In it were placed models of, on the right, the brake lever and, on the left, the gear lever at exactly the most convenient positions for his hands, ■with dummy brake and clutch pedals at tho right distance for his feet, and a steering wheel of the smallest possible dimensions —15in in diameter —in front of tho seat. Around this dummy cockpit as the nucleus, the car was built up."

REDUCING AIE RESISTANCE. After detailing the reasons for using a Napier Lion engine, the question of aircraft influence in the design of the body is referred to in these words: — "It is generally admitted that the fuselage of the Supermarine monoplane represents the high-water mark in streamlining for reduction of air resistance so far attained. It was, therefore, decided when getting out the outline drawings, profile and elevation plans of the car, to use the projected area or silhouette of the seaplane as a basis on which to work. The task to be accomplished was to design round the driver and the engine a car with a projected area the same or, if possible, less than the seaplane. This area, in the case of the supermarine, was, including the floats, approximately 12 square feet—a square measuring only 3ift each way. '' Obviously to equal this required the most careful thought and the greatest ingenuity in detail, but the problem was attacked with such great success that actually the projected area of the 'Golden Arrow' was rather less than that of the seaplane. ... It was not, of course, enough merely to produce what looked a satisfactory shape of body on the drawing-board and then start straight away to build it. ... A model of the design was, therefore, made and sent to the National Physical Laboratory at Teddington, to be tested in a wind tunnel. Not till this had been done and various modifications shown to be desirable introduced, was the outside form of the car definitelydecided upon."

WHEELS, TIRES, AND STEERING.

One of the biggest problems encountered was the design of the wheels and tires, and according to the writer of the book, they have together cost nearly as much as the whole of the rest of the car, and a secial programme of research and experiment was made in order to produce tires which would stand up to the conditions. Even so, however, there is only a small margin of safety, for it has been calculated that the tires will serve for 25 seconds only. This means that the tires will have to be changed after each of the four runs that are necessary in order that an average may be taken for the official records.

Touching upon tho question of steering, "the sido elevation has been planned with a view to bringing tho centre of side-air pressure as far back as possible in order to give the car 'directional stability.' For this reason, the body itself is extended at the back in a fish-tail fin making the total overall length of the car 27ft Gin. To obtain

1 rear wheel adhesion without excessive weight, the whole of the rear part of the chassis- from the point of 3ft (iin in front of the rear axle is enclosed in a horizontal-piano of streamlined section and so arranged that there is a powerful air pressure tending to hold the rear wheels on the ground. WHEELS SEPARATELY STEEEED. "The unusual arrangement of_ the mechanism for steering is no less inter-' osting. Instead of having the normal single steering box at one side with a push-rod running to the other wheel, each wheel is fitted with its own steering box, a third central box being interposed between them and the actual steering column which, by the way, is absolutely horizontal. The steering of each wheel is in this way separate, and although there is a carefully streamlined axle it is hoped to dispense with a track rod between the front wheels, as this would increase the resistance. It may, however, be found necessary to fit this after trial runs."

Apparently one of the great difficulties the designer had to contend with was how to keep the car low consistent with using a shaft drive. "The solution was found in what is probably a unique system of transmission in motor-car history. Two cardan shafts are used running along the side of the car at the height of the driver's hips, so that he sits between them. Where they pass through his cockpit they are enclosed in channels so that each side is a horizontal bulge. Each back wheel is, therefore, driven separately instead of through a differential. There is, in fact, in a sense no back axle, because this is split in the middle and the two wheels are entirely separate both in drive and support." The official name of the "Golden Arrow" is the "Irving Napier Special.'' the designer being Captain J. S. Irving.

As in the case of the car, the engine installed in the "Miss England" is a Napier Lion, and the goal aimed at is 100 miles an hour. The present record stands at 92.8 miles an hour.

The man behind the "Miss England" is Sir Charles Wakefield., The record holder is the American boat, "Miss America VII." "Miss England" will compete with "Miss America V 11.," running off the same marks. The distance will be 25 miles, the venue Miami (Florida), and the race will be the culminating event of the biggest regatta ever held in America and organised by the American Power Boat Association. The air' speed record is, of course, already held by Britain.