One day in 1931 there appeared at Brooklands a racing-car that stood out from the usual run of those raced there. A slim, eager single-seater, exciting yet something of an invader, at a place accustomed to a mix of entries. This car was so different, so technically advanced, compared to the stripped sports cars, the aged Grand Prix cars that had once known road circuits at places far away, the Specials built for racing at the Weybridge Track and various other ordinary racing cars, often of amateur conception.
In what was then a more remote America, they were used to such slim, highly developed monoplace racing machinery, some with ridiculously odd names, all looking more or less identical. But at sleepy old Brooklands this invader, while interesting and welcome, could only be seen as something slightly out of place. The “Right Crowd” was content with what it had and not anxious to see fields of American-type cars racing on the ancient Brooklands bankings. One was worth seeing, but not a horde of such cars. And “The Crowd” could console itself that the BRDC “500” was still won at a higher average speed than the “Indy 500”, where cars like the invader were rife, in spite of the small advantage of a rolling start.
The invader from across the Channel (and the Pond) was Mrs Gwenda Stewart’s Derby-Miller. I recall feeling some of the disquiet expressed above when I first saw it coming round to the Fork, with the driver wearing a very big floppy cap — could this be the masculine Gwenda herself, her engineering partner Douglas Hawkes, or a French mechanic? Incidentally, Hawkes used to race fast Morgan 3-wheelers and the 1912 15-litre Lorraine-Dietrich at Brooklands and made Morgans go very quickly indeed for Mrs Stewart and he tuned to perfection the car under discussion, which she had brought over for the 1931 BARC August races. Ernest Eldridge, too, who had made a Miller go quickly, had experience of both small and very big ancient racing cars; perhaps this was a good apprenticeship for working on modern racing machinery! (Even if Eldridge’s front axle did break up and cause him to crash, an accident which cost him an eye…)
No doubt inspired by Eldridge’s Miller, Hawkes had gone to the USA in 1930 and brought one back for Gwenda Stewart to drive. The Miller reputation was high since Frank Lockhart had set a fabulous class-F 1½-litre-class mile record of 164mph in California in 1927. The car Hawkes had purchased was said to have been clocked at 139mph on the Altoona Speedway. One gathers that Douglas had some difficulty in getting the Miller and its spares through the French Customs. After which, he and the faithful Fred Cann worked to put all in order.
It was certainly a car with a significant specification. The engine was a straighteight with the usual Miller barrel-shaped crankcase. The crankshaft ran in five plain bearings. The tubular con-rods had plain big-ends and there were two inclined valves per cylinder, operated by twin overhead camshafts, via steel piston-type tappets. The valve-timing gave 20 degrees of overlap. The engine was supercharged with a centrifugal-type blower running at up to 14,000rpm, fed from a modified Winfield downdraught carburettor, blowing at between 15 and 251b/sq in, according to the ratio of the gear-drive in use. Various cylinder blocks came with the car, enabling it to run in the 1½-litre or 2-litre record categories, the dimensions for the latter purpose being 59 x 76.5mm (1673cc), although as first imported it had a bore and stroke of 56.6 x 76.8mm (1490cc). In 1.6-litre form the power-output was quoted as 200bhp at 6500rpm, but the engine was able to run at 8000rpm, with another 1000rpm in hand, a very high crankshaft speed for those days. The actual power output was obviously dependent on the supercharger speed and compression-ratio in use, the latter varying from 6.8 to 8.0 to 1. These would be chosen in relation to the duration of the record runs to be undertaken. Lubrication was by dry-sump, from an 8-gallon oil tank, and ignition by a Bosch magneto.
The drive went forward through a plate clutch, which was locked in when fully home, to a three-speed-and-reverse gearbox and a straight-tooth crown wheel-and-pinion driving the universally-jointed halfshafts of the Miller front-wheel-drive layout. The tubular de Dion-type front axle beam was sprung on four quarter-elliptic springs and the dead-beam tubular back axle on half-elliptics. The driver sat low in the single-seater cockpit and the fuel tank was in the tail, slotted to allow for up and down movement of the back-axle beam. Eight exhaust pipes on the near-side of the car ran into a long exhaust pipe.
I believe that Hawkes had to virtually assemble this advanced Type 91 Miller from a pile of spares but, as I have said, he was experienced in working on, and driving, racing cars of many different sizes. At first it was run in 1½-litre form and broke several class records, putting the Class-F one-hour record to 118.29mph, and Gwenda got it up to some 140mph at the Arpajon speedtrials, along that narrow tree-lined road near to Montlhery Track, before the engine blew-up in a big way… The engine was rebuilt in 1.6-litre size, a sensible move at a time when the 1½-litre records were held at very high speeds. Gwenda then took many Class-E records, starting with the kilometre figure, at 129.01mph.
The car had by now been re-named the Derby-Miller. When living in England Mrs Stewart and Douglas Hawkes had started the Brooklands Engineering Co, with premises in the Brooklands Paddock, specialising in making parts for the racing fraternity, especially Martlet pistons, which facilitated making changes to the Miller engine. The company also sold Derby FWD cars, so the re-naming of the Miller might have been misconstrued as a publicity ploy. But I think it was justified, as by now Hawkes had made many changes to the car, and at least “Miller” was incorporated, instead of calling the revised car a Derby Special. . . That came later.
An early problem had been failure of the ball-races in the supercharger-drive, which Hawkes cured by fitting a third bearing and an effective system of forced lubrication to this area. Other aspects attended to included making a modified, much stiffer crankcase, new main bearings, even new-type con-rods and camshafts. The gearbox also had to be replaced, although still in 3-speed form, as the original was not up to the savage standing starts Gwenda indulged in when attacking short-distance “acceleration” records. In addition, two new centrifugal blowers were made in Paris and to avoid the FWD de Dion tube distorting and altering the angle of the front wheels, Hawkes put on two cross-bars between the spring hangers. Another problem had been the shearing of the clutch “solid-drive” on these standing-starts. So the single pin was replaced by three 7/16th in pins. Then the scavenge-pump was unable to cope when the castor-based oil overheated and thinned out on the longer record-bids. So Hawkes got Fred Cann to fit an extra pump, driven by an old wooden propeller that had once driven a fuel-pump on an aeroplane, now revolving in the airstream of the Derby-Miller on a spindle before its radiator; a rod in the cockpit brought this fan in, to drive the additional pump, when Gwenda saw that oil-temperature had reached a dangerous 85 degrees C. A second water header tank had been fitted, connected to the original header tank by vertical tubes passing through the gearbox casing, after water leaks here had eventually been cured with rubber grommets. Martlet pistons were naturally used. The chassis frame was modified and it wasn’t long into 1932 before about the only original Miller components remaining were the radiator and the carburettor.
The Derby-Miller was a very fast car, but it was hard on its Dunlop thin-tread racing tyres and apt to oil up its sparking plugs. However, it had set the second-fastest record made at Montlhery in 1930, when Gwenda put the World’s ten-mile figure to 137.20mph, only fractionally slower than the prevailing Brooklands lap record held by Kaye Don’s 4-litre Sunbeam — and hers was a 1.6-litre car. So when it was announced that she would bring the car over and attack that record at the 1931 BARC August Meeting, there was much speculation. Mrs Stewart had attended the BRDC dinner the previous winter, when she may then have been persuaded to return to the British track, which she had known from the early 1920s. By now the lady/car combination had put the class-E 10 km record up to 140.47mph and had lapped Montlhery at 141.36mph. Prospects seemed rosy…
Unfortunately the Derby-Miller had failed to take the coveted World’s hour record (standing at I 28.35mph to Voisin) when the magneto gave out, and later the plugs oiled up when the engine was throttled back to a safer 130mph. Another attempt ended after a worn pinion in the gearbox, which the usually meticulous Hawkes had decided to overlook, spoilt the opening lap. Then, after the World’s 100km record had been broken at 128.16mph, there came massive engine trouble… However, so as not to disappoint the Brooklands’ spectators, Hawkes rebuilt the engine rather hurriedly. But across the Channel things were different from those at Montlhery. The rougher track surface of Brooklands caused the driven wheels on the Derby’s short stiff springs to leave the ground and spin, with the menace of valves touching pistons. The target to beat was Don’s 137.58mph. Before the Bank Holiday crowds Mrs Stewart did only one timed lap, at a disappointing 112.17mph. (Birkin was also out after the lap-record, but the blower-4½ single-seater Bentley just failed to beat it).
“Disappointing!”; “A fiasco!”; “Must have been the English climate…”
But the Derby-Miller went back across the Channel and continued to notch up honours, after Douglas Hawkes and Fred Cann, who was in charge of it, had put it right. Gwenda’s Derby-Miller was not an easy car to drive and in gusty conditions she had been known to climb out exhausted. She also had stints in Austin’s “Dutch Clog” A7, trying to head off the menace of MG in the records field (109.13mph for five km). Other women drivers have displayed similar skills but Gwenda also knew all about the mechanics of the task, and was to crash the Derby after cutting the ignition at some 150mph to check plug condition. Rescued from a Montlhery garage fire, the Derby Special (“Miller” had at last been dropped) raised the track lap-record to 145.94mph and finally to a sensational 147.79mph and before that had got the Class-E mile record up to 143.29mph. Later the 5km figure went to 140.35mph, etc.
In 1935 this celebrated car was at Brooklands again, for a 50-sovereign Match Race against Mrs Kay Petre for the Ladies laprecord. The officials became scared of a race after seeing how fast the girls were going, so they were timed separately, Kay in the old V12 10½-litre Delage which Gwenda had probably seen Divo drive at Montlhery. Kay’s best, hampered by a slipping clutch, was 134.75mph. The Derby ran with wheel discs; it burst its silencer and nearly gassed its driver, who gave up, after a lap at 133.67mph, to the Bank Holiday crowd’s disappointment. But Gwenda had another try on the Tuesday before returning to Paris. She was then timed at 135.95mph, the all-time Brooklands local record for fastest lap by a lady driver, and also an all-time Class-E lap-record.
The car probably stayed in England, because Gwenda drove it, partnered by George Duller, in the 1935 BRDC 500 Mile Race. After timing-gear trouble in practice she got up to fourth place in this fast race (won by the 24-litre Napier-Railton, at 121.28mph) but the gearbox then played up and a broken piston caused retirement. Fate had not been kind to this particular invader from the Continent… It was offered for sale in April 1936 at £1200, with many spares, patterns, drawings, etc, because Mrs Stewart was thinking in terms of road-racing with her newly-built Derby-Maserati; although she was co-driver to Duller in the Duesenberg in that years “500”, but they experienced a slipping clutch. She had survived a ski-ing accident, and being rushed to London for an emergency operation in 1932, as well as a number of narrow escapes on the track. After it was all over she and Douglas Hawkes, whom she had married in 1937, lived peacefully on their yacht Eljois, cruising the Mediterranean. On reflection, some driver, some car!