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THUNDERBOLT

The Fastest Bean that Ever Was

By Guy Ravenscroft

 

INTRODUCTION

 

 

A 23 January 1998 newspaper report from New Zealand ran:

A millionaire motor vehicle collector plans to dig up a former city rubbish dump in Wellington in a search for Thunderbolt, the car in which Capt George Eyston set the world land speed record three times for Britain 60 years ago...”

Some of us will remember Owen Wyn Owen’s successful recovery of ‘Babs’ in 1969, from its 42-year entombment in the salty dunes of Pendine beach in South Wales. This was Godfrey Parry Thomas’s car that held the Land Speed Record briefly, in 1926.

However, in actuality, there is very little in common between the two cases. Firstly, it is not known with certainty whether Thunderbolt’s wreckage exists or not, whereas the battered Babs had been buried deliberately in front of spectators, following Parry Thomas’s fatal crash. Secondly,Thunderbolt had been ‘burned out’ during the September 1946 fire in the Exhibition hall where it lay in a storage crate. Thirdly, Thunderbolt had been fitted with ‘dummy’ engines for the exhibition, so one of the prime reasons for salvage was lost. Yet, there is a photo of the wreck taken in 1949, that indicates the intact structural integrity of the car, even to the aluminium nose panelling. The major disappointment is that there appears to be empty space where the massive gearbox should have been and that unit really was the ‘heart’ of the car. The last sighting of the wreck was reported to have been in December 1956, when lying beside the Wellington Airport - soon to be extended.

Bean people should be especially eager to see the Southward mission succeed, for Thunderbolt was by far the largest, fastest and most powerful Bean ever constructed and they know that Dave Cooksey is eager to start the rebuild as soon as possible. The more widely-read readers will already have noted a recent reference to Thunderbolt’s awesome potential in the correspondence pages of The Automobile, April 1997.

 

G.E.T. EYSTON

Capt George Edward Thomas EYSTON (OBE 1948; MC; Chevalier of Legion d’Honneur; MIMechE; MSAE) was born in England on 28 June 1897 and died on 11 June 1979. Correct pronunciation is Eastern.

At the age of 10, he went to Stonyhurst, the Jesuit college near Blackburn. In spite of holding the college in high regard and revisiting it in later life at least twice, he left after only one year - probably in favour of a private education. Among the early benefactors of Stonyhurst had been the brothers Joseph and Lewis Perry, industrialists who later gave their name to the car that eventually became the Bean. As a teenager, and under an assumed name (did his parents know?), he raced a motor cycle at Brooklands. On the outbreak of war in 1914, he joined the army.

Following distinguished war service, he went up to Trinity College, Cambridge, to read engineering. During vacation time, he raced in the Belgian Motor Cycle Grand Prix and took his GN light car to watch the French GP at Le Mans. After the race was finished, he toured round the rough gravel track in the GN !

After owning and maintaining two rather tired cars, a Coupe de L’Auto Sunbeam and a 4.5 Vauxhall racer, Eyston’s career prospects improved after a meeting with Lionel Martin and a switch to Aston Martins. His marriage in 1924 caused him to forsake cars for boats and he raced instead ‘Miss Olga’, a hydroplane fitted with a DOHC Aston Martin engine. Seeking more power, he commissioned a new Anzani engine from the factory, to which he fitted a supercharger of his own design – later manufactured as the ‘Powerplus’ - and gained an extra 35 bhp. Yet, success eluded him, so he returned to cars and bought Malcolm Campbell’s Bugatti. His competition career blossomed and he raced a great variety of cars in numerous classes and later helped his younger brother, Basil, into the sport.

During the 1920s and 1930s, a fairly lucrative living could be obtained from speed and endurance record breaking and Eyston inclined to this in all manner of cars, from ‘family saloons’ to the astonishing 8-litre sleeve-valve Panhard and specially-made vehicles. His association with his friend ‘uncle’ Ernest Eldridge, himself a holder of the LSR in 1924-6, was of great interest and led to the ‘Safety Special’ (a Chrysler chassis with a lightweight saloon body and a 9-litre AEC diesel bus engine) and ‘Speed of the Wind’ (a Delaney-built FWD car with 4-speed pre-selector gearbox and a 21-litre RR Kestrel aero-engine). Both these cars took 24-hour and other, records in their respective classes. Further reference to Speed of the Wind is given in Part 2.

For further reading of Eyston’s life, one cannot do better than reach for ‘Motor Sport’ back numbers: October 1974 and August 1979 relate to WB’s interview with Eyston and the Obituary notice, also by WB.

 

1935 - 1937 : GENESIS

Background

In the Autumn of 1935, George Eyston could scarcely have been other than impressed by Sir Malcolm Campbell’s smart organisation. 

Both men had arrived on the Bonneville Salt Flats, Utah, on the same day, although travelling separately and having greatly differing objectives. 

Campbell’s ultimate and long-sought motoring goal was the ‘magic figure’ of five miles a minute (300 mph) over the 2-way mile; he had been the first to four miles a minute in 1931, but had regarded this as but a ‘stepping stone’ to the next target. Eyston was there to take the World’s 24-hour distance record with Speed of the Wind. Both men had fitted a Rolls-Royce aero-engine to their respective cars, Campbell’s ‘Blue Bird’ having a sprint-tuned ‘R’ type V12 of 36.7 litres running on methanol-based fuel, while Eyston used an unsupercharged, petrol-burning. Kestrel V12 of 21 litres that the RR man said could “run for days without faltering”.

Neither man had been to Bonneville before... yet, on the seventh day of his visit, Campbell packed up and went home, having accomplished his objective and taken the LSR at 301.13 mph!

Campbell, who always seems to have had massive problems in his record attempts (that might have broken the spirit of a lesser mortal!), had lurid skids on both outward and homeward legs of his record run and both had occurred at about 280 mph, as he started to slow down. The first was caused by a burst front tyre, incurred as he tried a modest directional adjustment; the second when he decelerated too suddenly and set off a tail slide. The car was the first of the Blue Bird series to run with twin rear wheels, but it is not known whether the resultant reduction of ground pressure was responsible for the ‘instability’, or not.

There is little doubt that Eyston and his team, who were watching, would have taken note of the problems. In fact, it was well known that Lee Bible had been killed at Daytona Beach in 1929 by the fatal skid of the monster ‘Triplex’, when he decelerated too quickly and the grip of the rear tyres on the sand could not turn the three ‘Liberty’ engines.

 

The Design and Construction

Speed of the Wind, so successful in its first record attempt at Bonneville, had been designed by Ernest Eldridge and George Eyston and built by L T Delaney & Sons, Maida Vale, London. It used front-wheel drive because Eyston had been greatly impressed by the FWD Citroens that ran on long-distance record attempts on endless circuits of Montlhery autodrome. The Kestrel had been loaned by Rolls-Royce. Later on, this car was fitted with a sleeve-valve diesel version of the Kestrel developed by Ricardo, in order to take the compression-ignition records - which it did very successfully under the name of ‘Flying Spray’.

 

Ernest Eldridge had been born in the same year as Eyston and they were good friends as well as business partners. He had left Harrow School at the age of 16½ to study engineering - probably in France - and spent the early war years in France, driving an ambulance for the Red Cross. With a car constructed from the remains of ‘Mephistopheles’, a FIAT commercial chassis dating from 1907 to which he fitted a ‘bargain basement’ FIAT aero engine, he took the LSR at Arpajon, France, on 12 July 1924, and held it for two years. When another contender complained that it had no reverse gear (on a public road), he simply removed the driving chains and fitted longer ones that were ‘crossed’. There is no report that the car actually moved by this means, but the judges were satisfied! He was Eyston’s Team Manager at Bonneville, in 1935.

It is inconceivable that these two friends didn’t discuss design features of a possible contender with which to attack Campbell’s new record, although unhappily, Eldridge died of pneumonia only a month later (25 October 1935), thought to have been brought on by a chill caught in the mountains bordering the salt flats. They would have noted that Blue Bird weighed just over 5 tons, ran on six wheels and was powered by an engine producing a nominal 2,500 hp. It had a three-speed gearbox and made use of tail-mounted flaps as air brakes for use at high speeds. Surely, they might have reasoned, would not a car with a little more weight but TWO such engines, have been able to achieve SIX miles a minute?

 

Thunderbolt was built by Beans Industries Ltd in 1937, being shipped out to Bonneville at the end of August in order to ‘catch’ the period when the salt flats would have a dry crust. Although construction took 7 months, the actual ‘shop floor’ period was 6 weeks, which included assembly followed by a trial dismantling/reassembly.  Bill Sargent, Beans’ Works Superintendent who was later awarded the BEM, recalled operating a full night shift for this feverish period, for which he had a bed installed in the office!

Design of Thunderbolt would have been fitted into the year 1936 and Jean Andreau, an expert on streamlining, was called upon to advise on the overall shape.

 

Not being able to afford aircraft-style construction, Eyston used a fairly conventional pair of parallel beams, about 18” deep, from which to hang all the component parts. What today is referred to as ‘twin-steer’ was employed; that is, two sets of front wheels, independently suspended by tubular wishbones to reduce unsprung weight, with the leading pair having a narrower track. The second pair of front wheels was given shaft-driven inboard disc brakes, designed and patented by Eyston jointly with Ferodo and believed to have been made by Borg & Beck. Operation was by Lockheed hydraulics.

The twin rear wheels were also independently sprung, but in this case, the brakes worked on a pair of discs on the rearward extension of the main drive shaft and therefore acted through the crownwheel and second pinion. These, too, used hydraulic operation by Lockheed cylinders. None of the mechanical brakes was intended for use at speeds exceeding 180 mph, there being air flaps for high-speed use, as on Blue Bird, controlled by hydraulic jacks. All wheels were sprung by heavy Woodhead transverse leaf springs.

 

The two sprint-tuned ‘R’ type engines were mounted side by side on a cradle, with the two chassis beams passing between them and supporting the cradle. Each had its own clutch and drove into its respective side of the 5’6” wide 3-speed gearbox, in which it had its own layshaft for 1st and 2nd gears. By this means, the full torque of the two engines was only applied to the main shaft and the side thrust on this shaft was neatly balanced by the two drives.  No doubt, Eyston’s marine experience stood him in good stead with this system.  The main engine clutches contained a dog gear that was engaged when the main gearbox was put into ‘top’ gear, so making the clutches positively locked against slip.  In 1937, these dogs gave considerable trouble - referred to later on.

All the gears and final-drive bevel gear were contained within one massive unit.  In spite of the use of aluminium for the casing, the total weight was some 1,120 kg - nearly 1/6 of the total weight of the car!  It contained 45 gallons of oil, with pressure feed and was piped to the radiators for water cooling.  There was no differential, but a ‘following’ pinion on the crownwheel served the rear transmission brake discs.

 

An interesting contribution to the project came from Lord Nuffield, in that the complicated steering arrangements were made by Wolseley. Since the Timken Companywas also in his empire, perhaps the many taper-roller bearings in Thunderbolt were from Nuffield munificence as well.

Eyston took pains to reduce the unsprung weight of Thunderbolt, but was less concerned by thegreat overall weight of about 7 tons. Just one year after his final record-breaking run, he wrote,

...in order to transmit a certain horsepower there must be a certain weight pressing down upon the driving wheels to give proper adhesion. A car as light as those developed by the recent Grand Prix formula is admittedly a marvellous piece of engineering, but for safety at over six miles a minute I would rather sit inside the solid bulk of Thunderbolt”.

An observer today might well wonder why Eyston chose Beans Industries Ltd for the construction of his car. At the time, in fact, Beans were very well suited to the work.  They had excellent facilities for making almost anything in the engineering world and at that time were making, for instance, front axles for ERA cars, Gough engines for sports cars, Cotal electric transmissions (under license) and numerous cylinder blocks etc for production cars.  The Chairman was Victor Riley, whom Eyston knew well through his racing activities and who had been helpful to the ERA team, and the Managing Director was the amazing Cecil Bianchi.  Bianchi had been Charles Jarrott’s mechanic in the 1903 Paris - Madrid and other early motor races, had driven at Brooklands and appears to have been ‘acquired’ by Crossley when they took over Charles Jarrott & Letts Ltd, in 1910.  He became responsible for all Crossley test work as Works Manager and later Chief Engineer until 1927.  He then joined Bean Cars Ltd and helped them weather the crisis of receivership and re-birth in November 1933 and scoured the country to secure contracts to make the new company viable.  In about 1938, Jack Bean - a man of great influence in the motor engineering world - returned to the Beans directorship.

 

1937- 1938: TRIUMPHS


 

Thunderbolt was shipped to the USA on completion, in late August 1937. The engines had already been run in Beans’ test shop - accompanied by heroic sound effects and the dislodgement of accumulations of rubbish from the roof trusses! - but the car itself had not yet done any motoring. The gearbox and final drive had been run-in on the bench, by a 100 hp motor coupled to the tail shaft.

Eyston also took Speed of the Wind - with petrol-fuelled engine - to accompany Thunderbolt. He had followed up his 1935 24-hour record run in this car by capturing new records in 1936, over 24 and 48 hours. The American, Ab Jenkins, who had originated the entire series of long-distance challenges at Bonneville in 1933 and the Briton John Cobb, had both targeted Eyston’s records and his laurels were in jeopardy. Incidentally, Cobb’s challenging Napier-Railton and Jenkins's aero-engined Duesenberg 'Mormon Meteor' both still exist, but 'Speed of the Wind' was lost to Hitler's bombs during the war.

Unfortunately for Jenkins, the first to arrive and Eyston, the 1937 season turned out to be a poor one; they found the salt bed still covered by the winter floods. Eventually the salt dried out to a crust and Jenkins was able to secure new 12 and 24-hour records but as he completed the 24, the heavens opened and put 3” of brine over the area.! 

It was not until 28 October – very late in the year – that Thunderbolt was able to have its initial outing, recording a fantastic 309.6 mph over the mile, some 8 mph faster than Campbell 's existing record and one of the most spectacular 'first runs' of all time.

Unfortunately, the necessary return run was spoiled by the breakage of the clutch dog gears, attributed to improper synchronisation of the speeds of the two engines. It will be recalled that the gear train coupled the two clutch output shafts together, so that they were incapable of running at different speeds. The dogs, therefore, had no chance of survival if engagement was attempted when the engines were not synchronised.

While new dogs were being fitted, Eyston used the other car to try to regain the 24-hour record, but was denied success by a storm of rain.  For those readers unfamiliar with salt beds, perhaps it should be pointed out that rain water dissolves the salt and the puddles or floods are not simply water, but saturated brine.  To run a vehicle over a flood more than once can lead to deep grooving of the surface.

Thunderbolt was ready on 6 November and achieved 310.69on its first run.  Once again the return run was marred by broken dogs and Eyston realised that the design of clutch-locking system would have to be improved. He sat down with his crew and the AAA officials and was soon able to telephone the Offenhauser Co, Los Angeles, with a description of the parts he wanted made.  In a matter of days, these were delivered to him!

During the interval, Eyston had another try with Speed of the Wind and was able to take the record for 12 hours, before his supply of tyres was exhausted and he had to abandon further efforts.  The weather had been cruel that year.

At last, on 19 November - only 13 days after its last run - Thunderbolt was ready for a final effort before the winter set in.  The outward run, against a slight wind, was covered at 305 mph; the clutches behaved sweetly.  Refuelling and changing tyres took 16 minutes.  The return run was going well, when a rag left in the cockpit suddenly flew past Eyston’s face and knocked up his goggles.  Although temporarily blinded, Eyston was able to steer one-handed while straightening the goggles and he regained vision without having backed off the throttles, resulting in a run of 319 mph (km) and 317.74 (mile) and an average 2-way speed of 312 mph (km) and 311.42 (mile) for a new Land Speed Record!

When one reflects that a car travelling at 315 mph covers no less than 462 feet in one second, the goggle dislodgement incident reveals truly remarkable driving instincts - and the bravery of the AAA officials and timekeepers who operated the timing gear only 40 feet from the speeding car. 

In spite of this triumph, Eyston felt that the car had the potential to do better and to remain controllable at much higher speeds.  He therefore took Thunderbolt back to Beans for important modifications.

To reduce weight, nearly 1 ton as it happened, he had the three great transverse leaf springs replaced by coils.  Streamlining was improved by use of a smaller air intake - now oval in shape - with the ‘spent’ hot air set to exhaust through adjustable slats on top of the bonnet.  The tail was lengthened while the size of the vertical fin was reduced.

Reluctantly, Eyston arranged for the cockpit to be enclosed by a clear plastic roof.  He preferred open air, but had been disturbed by violent eddies at 300 mph and had obviously remembered the ‘rag and goggles’ incident!  He also fitted a respirator, in case of entry of fumes or smoke into the closed cabin.

 

The air-brake system, which Eyston had not used at all in 1937, was strengthened; perhaps to withstand greater speeds than originally envisaged. To improve the mechanical brakes, a Lockheed servo was fitted. Engine performance was improved by enlargement of the supercharger air intakes, on either side of the cockpit.

These modifications cost Eyston about £2,000: he said that each 1 lb of weight reduction cost him £1!

The modified Thunderbolt arrived in Bonneville at the end of June, 1938, when the winter floods were still between 5” and 10” deep. Eyston was aware that John Cobb was bringing out his new Railton car to challenge him for the LSR, and that it was of a very inspired design with two Napier ‘Lion’ engines, producing a total of 2,500 hp together, in an all-wheel drive car weighing around 3 tons. Its power-to-weight ratio was therefore the same as Thunderbolt’s 5,000 hp and ‘improved’ weight of 6 tons.

As it happened, when Cobb eventually arrived, he was able to get in his trial run first. It was reported that the two engines and two gearboxes (one for each ‘end’ of the car) proved difficult to master.

Thunderbolt’s first run ended abruptly: when Eyston tried the brakes at about 200 mph (they weren’t intended to be used over 180 mph), the new servo made them snatch fiercely and burn the linings. With the closed cockpit full of dense smoke, Eyston had to grab the respirator, following which, he managed to crack open the roof to clear the air and get an idea of the route the car was following. That was the last time that he used the servo!

By 24 August, the salt bed was ready for record attempts and Eyston had a very satisfactory first run at 347 mph, reporting perfect handling. The return run was even better, but it appeared that the silver car on the dazzling salt failed to trigger the timing apparatus. The officials requested that the car be painted dull black and there were no further problems on this account. Another try was made on 27 August, resulting in the raising of Eyston’s existing (1937) record by 33 mph to 345.21 mph for the mile.

Cobb then started his activities in earnest and Eyston decided to wait and see what happened, in the meantime giving Thunderbolt some drastic modifications, that appear to have been based on the Railton’s manifestly excellent design.

Eyston removed the tail fin and radiator from Thunderbolt (the Railton had neither) and closed off the front air intake to improve streamlining. There was neither the time nor equipment available to copy the Railton’s ice-cooling system, so Eyston did some calculation of the heat generated by the engines for each run and installed a large water tank in the nose of the car, with steam tanks alongside the cockpit. It was intended to change the water at the same time as the tyres, between runs.

Cobb’s first full-blooded record attempt was made on 12 September, with Eyston watching overhead in his plane! The resultant 2-way speed of 342.5 mph did not match Eyston’s LSR, but Cobb was encouraged to try again: he was becoming more at home in the car each time that he went out. A further effort was made on 15 September, in which he was successful in taking a new LSR at 350.2 mph (mile), being first to achieve 350 mph on land: his best one-way speed was 353.3 mph.

By this time, looking like a stranger with its smooth rounded nose and long finless ‘lizard’ tail, Thunderbolt was ready for another attempt. Eyston knew that he was taking advantage of the Dunlop safety factor in aiming at Cobb’s record, but perhaps reflected that the car was now over 1 ton lighter than the one for which Dunlops

originally designed the wheels and tyres. He was uncertain about the directional stability, now that he had no tail fin.

On the very next day, 16 September, Thunderbolt was brought to the start area at dawn, with engines already warmed up. Then followed an irritating delay of 45 minutes before the timekeepers signalled readiness, so that Eyston had cold engines to be push started at the beginning of his run.He had just 5 miles in which to work up to the measured mile and some of this distance was lost as the cold engines coughed and spluttered flame from the supercharger intakes. He used his long-suffering Ford truck to engage the tail and gather speed, until he let in the clutches ‘with a bang’ in first gear. The clutches were not used to start the car from rest.

As the engines warmed up during acceleration, in which 2nd gear was held for longer than usual,' the power built up purposefully and the run returned a creditable 356.4 mph over the mile - in a whisker over 10 seconds.

The higher speed and improved streamlining meant that arresting the monster took longer than before. Eyston used the air brakes and opened the cockpit roof to ‘spoil’ the airflow. Then at 180 mph, he used the wheel brakes, trying not to generate excessive smoke that might have blinded him (Parachute brakes were not known, at this time). The car overshot its normal depot and Eyston had to enter a zone of patchy soft salt while making his big circle. The Ford sank to its axles when trying to push Thunderbolt, and had to be manhandled. The team finally got to the depot after losing 15 of the precious 60 minutes’ allowance.

For the return run, Eyston wished that he could have had a longer run-up distance than the 5 miles, since he knew that he would still be accelerating within the measured mile. Thunderbolt was running beautifully and Eyston knew there was potential for higher speeds.

Starting the homeward run with still-warm engines, Eyston felt that he was in a furnace when he passed the line. All was well and he attained 358.6 mph over the mile, leading to the average of 357.5 mph and his thirdLand Speed Record.

While slowing down from the second run, Eyston deviated from the course without being aware until he found himself passing under telegraph wires that should not have been there! His brakes had faded out, but at 100 mph he was able to start circling and eventually to stop safely. In his writings, he spoke of the strange feeling at being driven back in a touring car, after he had driven at 358.6 mph on this last run and wondered whether the ultimate speed would be 500 or even 1,000 mph. He gave no hint of any more adventures at Bonneville that year, which ended with the ‘Fastest Bean that Ever Was’ holding the LSR for the second year’s end.

 

 

1938 ONWARDS :DECLINE & FALL


 

Writing in 1949 (Speed on Wheels), Sir Malcolm Campbell described events at Bonneville immediately following Thunderbolt’s LSR success on 16 September 1938:

Thunderbolt was streaking on to the measured mile at about 360 mph when the right-hand back end seemed to collapse.  Keeping his head in the coolest possible way, Eyston managed to avoid crashing into the dense masses of spectators and brought the wobbling monster to a standstill three miles from the end of the 12-mile course after it had ploughed deep trenches in the iron-hard salt.

The tyres had become entangled in the cowling, which, in turn, had caused the cowling to become entangled in a wheel and so bad was the damage that repairs could not be carried outon the spot.  It was bad luck, for there was no doubt that he was travelling faster at the time of the mishap than he had ever travelled before.  Twisted and torn, Thunderbolt was shipped back to England.”

Even making allowance for the ‘flamboyancy factor’, Campbell’s story must have had a basis in fact and it appeared odd that Eyston, who devoted no less than 24 pages in his 1939 book (Fastest on Earth) to the Thunderbolt activities, made no mention of such an incident.  Other authors also made no comment, but it was that doyen of auto-historical scholarship, Wm Boddy MBE, who solved the ‘mystery’ in his 1964 book (The World’s Land Speed Record). He wrote,

(following the 16 September run) “Thus encouraged, Eyston decided to have another shot, although Cobb was on his way home. It was actually possible for him to use up some of his rival’s tyres that had been left behind. But while the car was travelling at full speed part of the body disintegrated, a cowling becoming entangled in one of the back wheels and the suspension was damaged. Eyston held the ensuing skid and brought the car safely to rest... The car spent the war safely stored in New Zealand and is still there.”

It is interesting that, at the time this had been written (1964), there had been no news from New Zealand. The post-1938 story is taken up by Roy Southward of Wellington, New Zealand. In a letter to Peter Sargent dated 8 March 1998, he wrote,

In 1939 the Thunderbolt went to New York for a show, and then came to New Zealand for the Centennial Exhibition which opened on 8 November 1939. Before coming here, the two R Type Rolls-Royce engines in the car were taken out and replicas put in for the exhibitions. The original engines still exist in England. One is in the Air Force Museum at Hendon, London.

The war delayed shipping the car back to England and it was stored in the Exhibition Building which was next to my college.  In 1945 or 1946 I remember crawling inside a crate and sitting in the cockpit of Thunderbolt (The building and the car were destroyed by fire in September 1946).  This contact with the car sparked my interest and I had thought of trying to find out what happened to the car when I retired.  Although not quite retired, I have started on the search as time will make the search more difficult if I do not start.

To date, one person thought he may have seen the car dumped in a rubbish tip, I have been given a photo taken in 1949 of the burnt wreck and the last sighting of the car was in December 1956 when it was lying beside the Wellington Airport.  The Wellington Airport was extended in 1957/58 and it would have been moved.  Buried or cut up for scrap is the question.  I really need verification from someone else on what happened to it in order to start the physical search.  If buried I am sure it can be found.”

 

Recent discussions with Dave Piggott, of the RR Heritage Trust, gave rise to the possibility that Thunderbolt had been fitted with scrap engine parts, rather than wooden dummies.  The R type engines spent much of their lives in the dismantled state anyway, since they were so highly stressed and tuned and Eyston’s relations with Rolls-Royce were on a cordial basis: he had, in fact, been offered a job by them when installing modified Kestrel engines in Speed of the Wind/Flying Spray.  He might, therefore, have been able to obtain the scrap parts to fit Thunderbolt for exhibition.

Close examination of the photo of the burned (upside down) wreck indicates that aluminium panelling of the nose, tail and upper surface survived.  What appears to be an engine lies alongside the right of the wreck, but the great gearbox is entirely missing.  This unit would only be removable by being broken up or by complete dismantlement of the chassis and separation of the two ‘rails’.  Since such a gearbox could find a use in a twin-engined boat (with a single screw), it would appear likely that it was removed in England, before shipment.  The steel road wheels are seen, along with the pathetic remains of the holding-down straps on the front hubs for securing the car in its container.  The side panelling, which was removable for maintenance, is, as would be expected, not in place.

Without engines or gearbox, then: should Thunderbolt be sought and exhumed? There are many who would support this action.

Thunderbolt is a symbol of endeavour; of courage; of triumph; of private enterprise. Above all, a memorial to an outstanding and modest gentleman and hero - Capt George Eyston, OBE.

 

 

1940 : NEW ZEALAND
CENTENNIAL EXHIBITION

 

Marking the centenary of British sovereignty over the land, the exhibition was on a grand scale, with pavilions or courts for the New Zealand Government, the United Kingdom, Australia, the Dominions, Engineering, Motor & Transportation, with numerous other and smaller halls for entertainment and refreshment.

The actual exhibition area covered 6 hectares and was designed by Edmund Anscombe. During the 10 years’ of planning, Anscombe visited other exhibitions that included those of 1939-40 in San Francisco and New York World’s Fair.  It was probably the latter that drew Thunderbolt for a few months, before transfer to NZ.

The United Kingdom pavilion (No 4) was a detached building in the south-east comer of the area, guarded by a pair of irascible lions that glared at the Australian pavilion (No 5) opposite, across Centennial Avenue, in the north-east corner.  Just outside this eastern boundary lay the northern part of Wellington International Airport, the southern end of which was built on land reclaimed from Lyall Bay.

 

Rongotai College, which Roy Southward attended, was situated immediately to the north of the exhibition area. Reading ‘between the lines’ of his letter, one would suppose that the entire exhibition lay in a state of semi-dereliction during the war years: a sitting target for vandalism perhaps, although it is not known at this time what caused the fire in pavilion No 4.

Whether the gearbox was removed by Eyston in England, or by another by theft, it is most unlikely that Eyston would have made any plans for Thunderbolt, once this vital component was no longer in the car. It is quite likely that he would have welcomed the insured value of the car, following the fire that brought the roof down on its sarcophagus.

One weeps for Thunderbolt at this ignominious end to a splendid career.

Without Thunderbolt, the only surviving part of the exhibition today is the huge sculpture of Kupe, the legendary discoverer of the islands, with his wife and magician, that stands in the foyer of Wellington railway station.

 

THUNDERBOLT’S ENGINES 

 

The Rolls-Royce ‘R’ type engines are so interesting, that they deserve their own section of this review.  Had it not been for the existence of the Schneider Trophy competitions, it is doubtful whether such engines would have been developed so early in the history of flight.

The trophy had been presented to the Aero Club of France in 1913, by M. Jacques Schneider, for international seaplane racing.  From 1913, the contest was held annually, apart from the war years, being won variously by French, British, Italian and American teams.

In 1927, it was won by a (British) Napier-engined Supermarine ‘S5’, at 281.68 mph.  There was no contest in 1928, but in 1929 aSupermarine ‘S6’, powered by the early (1,800 bhp) R type engine, won at 328.63 mph. Again, there was no contest in 1930, but in 1931 the Supermarine ‘S6B’, powered by the later (2,300 bhp) R type engine, won at 340.08 mph.  Since this was their third consecutive victory, Great Britain claimed the trophy outright and there were no further contests.

Incidentally, it had become customary for Schneider contenders to try for the Air Speed Record (ASR), which (at the time) also was the World’s speed record and in September 1931, Flt-Lieut G H Stainforth in a S6B with ‘sprint-tuned’ R type engine, became the first person to exceed 400 mph and finally took the record up to 407mph.

One feels a measure of sympathy for the Italians, at the forefront of technology, who had been developing an even faster contender for the Schneider.  The British had ‘taken away the ball’ just in time, for the foiled contender went on to achieve 440.76 mph in 1934.

In brief, the R type is a highly-supercharged VI2, 6.6” bore x 6” stroke, of which the swept volume is 2,227 cu ins (36,582 cc).  These dimensions were carried through to the ‘Griffon’ that was developed from a de-rated R type.

Production was in four batches; 7 engines in 1929 for the Air Ministry (R1 -R15) followed by another 2 for commercial purposes (R17 & R19); then 6 engines in 1931 for the Air Ministry (R21 - R31) followed in 1932 by another 4 for commerce (R33 – R39).  Note that only ‘odd’ numbers were used and there was no R13.

It is believed that Lord Wakefield (Mr CC Wakefield of Castrol) had a hand in ordering all 6 of the commercials. R17 and R19 went into ‘Miss England II’, which sank causing the death of Segrave and (RR engineer) Halliwell.  These two engines were recovered: R19 was believed to be Eyston’s spare engine, before he handed it over to Campbell as a spare.  Campbell had bought R37 in ‘sprint’ tune and it seems to have been his favoured engine on land and water.  When he disposed of his last Blue Bird car (now in Alabama), he seems to have put R19 into the car and kept R37 for his boat.  There seems to be no evidence that R19 was actually his!  It is on record that Campbell had R39 on loan from RR as well as R19.

Fortunately, Thunderbolt’s two engines are well established as being R25 and R27 and both still exist.  Rolls-Royce Experimental Dept records state that in November 1933, both R25 and R27 had been dismantled, but that in 1937, they were delivered to Beans Industries.  Since they were required to drive through the Bean-built gearbox, the airscrew reduction gear assemblies were not sent.

Records available in the Rolls-Royce archives indicate that R25, now in the RAF Museum, Hendon, took the WSR/ASR on 13 September 1931; and R27, now in the Science Museum, London, set a new record of 407 mph on 29 September 1931.  This is disputed by records in the Campbell/Leo Villa file that indicate that R37 was exchanged for R27 before the record-breaking run.  The claim that both of Thunderbolt’s engines held BOTH air and land speed records at various times has therefore to be suspended until resolution of the dispute!

Postscript: Several months after the preceding section had been written, some correspondence in the hands of the Eyston family was found, that indicates both Rolls-Royce and the Science Museum accepted that the two engines were owned by Eyston in 1948, the year in which he handed them to RR for cosmetic treatment, prior to being exhibited.  He maintained insurance cover until 1970 - hardly likely if, as is commonly believed, he had simply ‘borrowed’ the engines from RR. 

 

NOTES ON FUEL


 

The boiling point of fuel increases with a rise in supercharger pressure and Thunderbolt’s fuel had to be blended carefully for acceptable volatility, high anti-knock rating and an alcohol content to cool the mixture and raise its density. In addition, the altitude of Bonneville, about 4,300 ft above MSL, had to be taken into account.

In 1931, the Schneider Trophy and ASR engines were set up as follows:

 

Race                                       ASR

 

  Fuel:                                               20% Petrol (Calif)                              _

 

                                           70% Benzole                                  30% Benzole

 

                                           10% Methanol                                60% Methanol

                                                                                              

                                                    -                                          10% Acetone

 

Additive (TEL):                          4 cc/ImpG                                    5 cc/ImpG

 

Octane Rating:                          92

 

Compression Ratio:                    6:1                                               6:1

 

Blower PSI:                               +17.5                                            + 20.1

 

Blower ratio:                             7.47:1                                          7.94:1

 

Power BHP/RPM:                       2,350 at 3,200                              2,530 at 3,200
 

                                                                                                    R15 2,783 at 3,400

 

Throttle opening:                      ‘less’                                            ‘more’

 

Description:                               Race                                            Sprint engine

 

It is believed that Campbell’s R37 had the 7.94:1 blower drive.  Thunderbolt’s are not known at the time of writing, but were probably on 7.47:1.

 

Notes:

TEL: (Tetra-ethyl-lead) Excellent anti-knock compound in petrol, but not in alcohol or benzole.  Highly toxic, affects breathing, harmful to sparking plugs, valves etc.

Acetone: Good binding agent for alcohol/petrol/benzole blends.  Confers volatility.

Petrol: Comparatively low anti-knock value, but has good volatility, wide boiling range and ‘stability’.

Benzole: (Benzene) Can be employed in higher quantity than petrol in racing fuel on account of its higher anti-knock and better latent heat values.  A helpful binder of alcohol and petrol, but 5°C freezing point makes it unsuitable for normal aircraft etc.

Methanol: An alcohol, thus containing oxygen in its molecule.  Confers cooling effect on combustion and helps increase density of the mixture, leading to increased power generation.  Superior latent heat and lower boiling point than ethanol (another alcohol) and unaffected by the booze tax aspect of the latter. Has been termed a consumable intercooler.  Disadvantages are corrosive effect on light metals and difficulties with starting.

 

 

NOTES ON TYRES

 

The story of British supremacy in Land Speed Record attempts, from 1926 (Parry Thomas) until as late as 1963, is very closely linked to the enthusiastic support of the Dunlop Rubber Co.  The willingness of Dunlops to produce appropriate tyres - and usually the wheels to carry them - paved the way for the rapid development and success of the LSR car.  Contenders would have liaised with Dunlops at an early stage of design.

Important factors would have been:

  • Designed ultimate speed

  • Max power available and how distributed

  • Weight to be carried by each tyre

  • Type of road surface

From these, the power to be transmitted per sq inch of tyre-contact area on the road surface would be calculated and the centrifugal force index (CFI) and rotation speed of various tyre diameters would be examined, to establish the optimum.

The contact area was normally about 20 sq ins, or a little under and the power transmitted showed a gradual increase over the years, from around 25 hp per sq in in 1926, using 10-ply cotton-fabric casings, to around 40 hp per sq in by the mid-1930s, with 14-ply cotton.  Thunderbolt appears to have been the first LSR car to have been given rayon (Fortisan I) casings and the 10-ply 31 x7tyres supplied were also used by Cobb’s Railton 4WD car thatcame out a year later.  This size was a big reduction from the 37 inch cotton ‘giants’ that immediately preceded it!  Dunlop disc wheels, with alloy rims, were used.  Treads were wafer thin, otherwise they would have been thrown off by centrifugal force.  Tyres had therefore to be changed after each run.  Cobb always insisted that ‘slave’ tyres be used in bringing the car to the start line; no doubt, Eyston would have done the same, but is not on record for this.

 

REFERENCES

Publications

Flat Out, Eyston. Miles 1933

Motor Racing & Record Breaking, Eyston & Lyndon. Batsford 1935

Speed on Salt, Eyston & Bradley. Batsford 1936

Fastest on Earth, Eyston. Miles 1939

Speed on Wheels, Campbell. Sampson Low 1949

World’s Fastest Cars, Horsley. Citadel 1955

MontlhEry, Boddy. Cassell 1961

The World’s Land Speed Record, Boddy. MRP 1965

Encyclopaedia of Aviation, Burge. Pitman 1935

  Motor Racing, Lonsdale, Vol XXVII. Seeley Service 1939

  The Land Speed Record, Tremayne. Shire 263 1991

  Lost Causes of Motoring, Montagu. Cassell 1960

  Motor Sport, WB. Numerous 1950-1990, esp Oct 74, Sep 70

  Ten Years of Motors & Motor Racing, Jarrott. E Grant Richards 1906

  Old Motor, Vol 5 No 9; June 67
  The Times obit., 23 Nov 1979
  The Daily Telegraph, 23 Jan 1998

 People

  

Peter Sargent, numerous pictures and data on Thunderbolt.

Jeffery Gray, data on NZ situation, pictures and engine/fuel info.

David PigottMike EvansPaul Foulkes-Halbard for engine info.

William Boddy MBETom DelaneyJohn EldridgeJonathan Wood,

Anthony Perry and Mike Hawke for other info.

Alexander Turnball Library (NZ), Guy Griffiths collection, Desmond

SouthgatePeter JelleyPhil Spencer and Louise Troman of the

Black Country Museum for pictures and references.

 

With great thanks to all these and others unamed, for their help in putting together this story

 

 

Biographical Note

The writer, Guy Ravenscroft, was bom in Walton-on Thames in 1932. He trained as a Mining Engineer at the Camborne School of Mines and worked oversea for over 30 years, specialising in alluvial mining. With his wife Wan, he then settled in Somerset and ran a hotel for 10 years, until becoming ‘elderly’.He bought his first car in 1950, for everyday use. It happened to be aBean2-seater. He grew very fond of the Bean and started the Association of Bean Owners in 1951. In 1953, he bought a Marlborough ‘racing light car’, and added a Renault ‘45’two years later. When rallying the Renault in New Zealand with Wan and the first daughter Nicola, then aged 1, he fell for the ultra-sporting appearance of the pair ofSizaire-Naudins also on the rally and was able to find one for sale in England later that year. This luckless machine has dominated his life ever since, but is expected to emerge again into the wide world, running perfectly, by the Millennium.His last oversea job was in Saudi Arabia, developing a new mine on a water-logged salt flat near the east coast. The unique features of a salt flat - which has been known to swallow a bulldozer within minutes - and the searing heat of the ‘hot’ season, have left a lasting impression and curiosity about other salt flats. This and his current position as Hon Historian of the Bean Car Club, fit him quite well to write about Thunderbolt on the Salt.

 

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Thunderbolt with black stripe and crew

Source: Guy Griffiths

Thunderbolt, prior to body framing, brakes, etc, 1937

Source: Powers/BCM

Now with body frame, showing rear brake discs

Source: Peter Sargent

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Thunderbolt almost ready, air brakes being fitted in the tail 

Source: Foulkes-Halbard

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Gearbox casing, after machining; Bill Sargent, assistant Frank Hodgetts on left

Source: Peter Sargent

Bill Sargent (Supt. Of Assembly) with the spread of gears, shafts and bearings

Source: Peter Sargent

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Completed gearbox under test in Bean's works

Source: Peter Sargent

Rear view of gearbox; tail shaft on left

Source: Peter Sargent

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Just before departure; from left: 

Bert Denly, ANO, Eyston, ANO, ANO,

Hodgetts, Bill Sargent, ANO, Cecil Bianchi

Source: Spencer

Wheeling out Thunderbolt for shipment, August 1937

Source: Spencer

Bonneville 1937; Thunderbolt at service station

Source: Boddy

1938 rebuild; cockpit, revised suspension and air intakes

Source: Peter Sargent

Rebuilt Thunderbolt ready for shipment, 1938

Source: Guy Griffiths

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Bonneville 1938; Thunderbolt before first run

Source: Peter Sargent

Thunderbolt's final effort, rounded nose and without tail fin 

Source: Eyston

Thunderbolt exhibited at the World's Fair, New York 1939

The tail appears to have been foreshortened – to reduce transport costs ?

Source: Eyston Family

Thunderbolt's wrecked remains; Wellington (NZ) 1949

Source: Peter Sargent

Bab's wrecked remains; Pendine 1969

Source: Motor Sport

One of the lions outside the UK Pavilion Centennial Exhibition 1940

This is where Thunderbolt spent six miserable years in a box, before being burned

Source: Alexander Turnbull Library (G-100298-1/2-)