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STEWART STEWART TRESILIAN - sometime chief engineer: a CV
Richard Hodgson gave a talk about Stewart Tresilian
at Coventry University to the Rolls-Royce
Heritage Trust on 8th January 2001. This C.V. will be altered in due
course to bring in new and additional information that was mentioned during a
session after the talk.
Stewart Tresilian: 9th January 1904 - 20th May 1962
1917-1922 Wellington College, Berkshire
1922-1925 Cambridge University (BA in Engineering)
Hill climbing and racing in his Eric Longden "cycle-car" - capable of 70mph! Probably first met Raymond Mays whilst racing/hill climbing.
1925-1927 At JAP (Prestwich motor-cycle engines)
No presently known information about his time there. Completed his apprenticeship and became a member of the then IAE.
Late June / early July 1927 - late Jan / early Feb 1936, Rolls-Royce, Derby
Usually said to have been the first Cambridge graduate apprentice at Derby, though in fact appears to have been taken on as a salaried member.
First attached to Hives in Experimental (until about late 1928 / early 1929):
Car suspension calculations, slightly later gearboxes, finally on all aspects of the cars.
Photograph exists, taken by Tresilian, of a test outing of an experimental chassis with just Royce, Rowledge, Hives and Elliot.
1929 to late 1932 / early 1933, attached to Rowledge, chief (aero) designer (though also involved with the cars):
Government records show that Tresilian was well known to the Air Ministry as the "chief aide to Rowledge".
Kestrel then "R" engine. Did many of the calculations on valve gear, con-rods, crankcases, crankshafts, bearings, and superchargers (but not ram intakes nor supercharger drive). Main aim seems to have been to increase power by increasing engine speed. Several people then involved with the "R" attribute the decision to increase the speed of the 1931 "R" to Tresilian.
In a letter dated 23rd May 1962 to Tresilian's widow, Frank Allen said that he had "always been grateful for the immense trouble he took to get me started on superchargers in 1931 a subject quite new to me then." Tresilian then did much work on the "G", the Griffon's early 30's predecessor, that was put on hold due to problems with the PV12/Merlin.
Tresilian's real interest lay at Rolls-Royce was on the car side, especially the 3 1/2 litre Derby Bentley (with which he had been involved from the beginning). He designed ohc and 4-main bearing engines for the Bentley. At least one was apparently built in late 1935 [sic] but was, so it is said, not constructed as designed by him. He also headed the design for the still still-born ohc V12 engine for the Phantom III starting in about in late 1933. Tresilian studied at length the possibility of supercharging and turbosupercharging the Bentley - an option included water injection. He argued strongly that Derby should use torsion bar front suspension, though gave advice on the GM-type suspension then used. Tresilian was much impressed with the Citroen Traction Avant as soon as it came out.
He was involved in certain design aspects of the PV12 (Merlin) - both its strongest and weakest parts, and in curing its initial very severe crankshaft torsional vibrational problem. As a result of the latter, the late Walter Hassan said that Tresilian had a "legendary" reputation in the industry.
Whilst at Derby, Tresilian raced his Bugatti 35 at Donnington, winning one or two races, even though the Rolls-Royce had tried to ban him. C.T. Delaney told me that Tresilian was held in respect by other racing drivers. Tresilian was higher placed than Dick Seaman on one occasion.
Tresilian bought his type 35 Bugatti with his bonus for 1928! In 1934, he bought a type 55. He was not the only engineer at Derby with an expensive car: Ray Dorey also had a Bugatti, Ivan Waller a top sports Alvis and Harry Grylls an Aston Martin (which he also raced at Donnington).
He did calculations for ERA whilst at Derby, though few details have survived. Several people recall that Tresilian and Rowledge, RR's chief aero-engine designer, did work for Rowledge's old firm, Napier. Unfortunately the nature of the work is not known - not even whether aero or for the projected 1930 Napier car.
1936-1938 - Lagonda, at Staines.
Invited by W.O. Bentley to become chief designer after Harry Grylls had declined W.O.'s offer. The new big Lagonda would have been a rather different car had Grylls accepted.
Tresilian took Frank Stark and Reg Ingham with him from Rolls-Royce. The V12 Lagonda followed the general principles Tresilian had set out for a different (and unbuilt) version of the Phantom III - relatively short stroke ohc engine with 4-main bearings to allow high engine speeds, torsion bar i.f.s, gearbox constructed in part out of light alloy.
Had Lagonda more money, he planned the V12 to have an aluminium and less undersquare engine, de Dion rear set-up and be turbo-supercharged! Enormous problems with the manufacture in the UK of the very long torsion bars.
Early 1938-May / June 1939 - "chief" of Templewood Engineering at Slough, though also continued to advise Lagonda.
Templewood was an offshoot of High Duty Alloys, itself part of Hawker Siddeley, set up for Tresilian by Devereux. Its brief was to exploit non-aero uses of light alloys. First commercial extrusion in UK of special aluminium alloys.
Tresilian was the 4/5 "manager", Bertelli, ex-Aston Martin, 1/5 "manager". The arrangement seems to have worked well!
Work included designing and partly building a very advanced prototype light alloy car with no chassis as such, all round independent rubber [sic] suspension, and a very oversquare 4 cylinder 4 main bearing ~ 2.3 litre sleeve valve engine (stroke 75% of the bore) and an "all-alloy" 3 speed all synchromesh box to give American "lazy" style driving.
Roy Fedden used to visit the firm [the car or its engine may have been financed by him personally].
Bertelli was responsible for the styling of the light alloy car.
Georges Roesch and Jean Bugatti also used to visit.
During this period, the firm did consultancy work for Rolls-Royce on aluminium and magnesium con-rods and pistons (for Rm). Other work was done for Rm on light alloys but no detailed records have been found.
One-off work was done on racing car projects including some variations to Staniland's Multi-Union.
Tresilian announced he was leaving by telling his designers: "I am through with you, I am being sent to Coventry" (his new job was thrust upon him by Sopwith against his will in odd circumstances - a long and very tortuous story). Bertelli then became overall chief.
Whilst at Templewood, Tresilian proposed disk brakes and stressed skin construction for racing cars in 1938 (probably influenced by aero designers who had by then considered Lanchester's disc brake concept). First drawing of the "Bacon Slicer" disc transmission brake in 1939 as later used by BRM.
May [?] 1939 - January 1942 - chief engineer of Armstrong Siddeley, aged just 35. He appears to have been asked about the prototype 20hp car in about February 1939.
He was brought in to replace Col. Fell who had "left" in February 1939. Tresilian was expected to clear up the appalling mess of the Mark II Deerhound 1500hp air-cooled (7x3) aero-engine. His appointment, at the very least, was influenced by the Air Ministry and upset quite a few people including most of the board [sic]. His redesign, the Deerhound Mark III (1800hp projected output) was a substantial improvement over all previous Deerhounds. According to W. H. Lindsey and others, he nearly pulled the rabbit out of the hat. His proposed Mark IV in power plant form was never built.
He brought in T.P. de Paravicini, formerly of Rolls-Royce, patentee of positive thrust exhaust ejectors and who had done gas-turbine work on paper from about 1935 to 1938 whilst at Rolls-Royce. "No-one then took any real interest in gas-turbines at Rolls-Royce" - the late T.P de Paravicini in 1992. de Paravicini and Brian Slatter, his bright post-graduate student, proposed UDF set-ups in September 1941 in a series of two papers that fortunately survive, though Brian Slatter has said that, with the benefit of hindsight, the UDF proposals would not have been workable.
A precis of the Deerhound [and Wolfhound] story is too long to give here [but see above].
Tresilian wanted to build Whittle's engine as early as August 1939 [sic], but was not given the chance - another long story.
He designed an all plain bearing Cheetah in case the supply of rolling element bearings became difficult. After that, he favoured plain bearings whenever possible. He rationalised Cheetah production by replacing forgings and machining operations with die-castings wherever possible. This work was highly valued at the Ministry as it speeded up production and reduced costs.
Tresilian also designed the Wolfhound, an extremely advanced 2,600 to 2,800hp 24 cylinder (6x4) [sic] engine (even firing per row, straight banks, designed ab initio in power plant form). This was cancelled by M.A.P. in October 1941. Few details are known. However, both Rolls-Royce and Bristol wanted the engine cancelled. Ronnie Harker recalled that Hives was not overjoyed at the prospect of Siddeley's designing and manufacturing an original Tresilian design.
Tresilian had a new car design built - but apart from two photographs thought to be of that car, little else is known.
Tresilian never had the backing of parent Hawker Siddeley, or of Siddeley's general manager, Dr. Rowell, who had also hoped to become Chief Engineer. They instructed Tresilian to back F.A.M. Heppner's A.S.H. gas-turbine contra-flow rotating shell engine design (a bit like the Dr. Griffiths's CR engines). Tresilian refused, wishing instead, in late 1941, to back very close collaboration with Metro-Vics on the F2 [sic] and look further into de Paravicini's proposed axial gas-turbine proposals, including an un-ducted fan unit. He told Sopwith and Spriggs, directors of the parent Hawker Siddeley, that Heppner was making monkeys out of the lot of them. As a result, he was fired on 19th January 1942 and given two hours to leave. He left by telling some of his designers: "I have upset the apple cart and have to go". The A.S.H. in its various proposed guises harmed Siddeley's reputation with the Ministry and was never completed [This part of Tresilian's professional career has been covered in detail in a talk about early Armstrong Siddeley gas turbine projects].
The Armstrong Siddeley episode very deeply affected Tresilian for the rest of his life and he rarely spoke about it. The late George Day, who joined ASM in about 1929, recalled in 1991 that Tresilian, by then at Bristol Engines, was the first senior Bristol engineer to visit after the merger with Armstrong Siddeley was announced in late 1958. He asked Day what they were now doing. After Day gave a run down of current work, Tresilian suddenly said, with tears in his eyes: "I let you all down very badly". Day added that he would never forget the incident. The late W.H. Lindsey, later to be Armstrong Siddeley's last Technical Director, said in 1991 (and again in 1993) that "they fired the wrong man - it should have been Heppner".
Late 1942-March 1945 - USAAF/RAF engine co-ordinator.
Tresilian had been unemployed for nearly 9 months until he was finally given a job.
He argued in a series of papers that rather than develop the Griffon, the Merlin should be developed to produce yet greater power by operating it at a somewhat higher engine speed (as he had done over 10 years earlier with the "R").
He also pressed for engines and installations to be designed with servicing in the field kept in mind.
He took out papers in late 1944 to emigrate to the US.
March 1945-1948 - Rolls-Royce, Hucknall:
Taken on in a great rush by Rolls-Royce. RR, through its Bentley subsidiary, had just commenced proceedings against Lagonda over the use of the name and mark "Bentley". RR may have wished to minimise the risk of Tresilian giving evidence for Lagonda. Just before the offending Lagonda advertisement appeared, Tresilian had been told that no position was available at Rolls-Royce ("difficult to fit in an ex-chief engineer"). In the end, as obliquely referred to RR's solicitors' and counsels' papers for that case, Tresilian declined to give evidence for RR!
Tresilian set up his own "private" engine design office without the knowledge let alone approval of Derby!
Its main projects included the design of extreme speed sleeve valve 2 and 4 stroke engines of about 10 litres to produce about 2500-3000 hp more economically and for a lesser weight than turbo-props. The 4 stroke would have required Triptane (150+ octane). This paper project was nearly completed before anyone at Derby came to hear about it. The Clyde and Tweed turbo-props did not compare favourably on paper. However, even then it was realised that development costs would have been exceedingly high.
He also headed a jet trainer project.
Declined 3 times Lord Hives's "request" to return to Derby (he refused point blank to work under or even with Lombard) - resigned when he heard that his office had been moved one weekend to Derby and became an independent consultant.
It is recalled that he and Dorey, chief of Hucknall, essentially only discussed cars in the canteen, bewildering many there. Both did work for the post-war "ERA", and the emerging "BRM" entity.
The late Ronnie Harker recalled seeing an advanced 4 cylinder very oversquare car engine of about 2 1/2 litres on Tresilian's "private" drawing board. This eventually became BRM P25 and was no doubt based in part on the bottom end of the Templewood design.
1948-1953 - "Independent Consultant" (save for BRM and Connaught, with Erling Poppe).
During this time, Tresilian patented the concept of an engine with a short stroke about 3/4 of the bore having three or more valves per cylinder. He gave presentations, estimated comparative performances and G.A's. of his multi-valve short stroke engine to, inter alia, Austin, Morris, Talbot, Daimler and Vauxhall. He had already patented the sliding-tube de Dion tube.
Much of his time spent with BRM and, to a lesser extent, Connaught.
Instantly fired by Owen on his assuming control of BRM - Owen asked him what he really thought about Peter Berthon. Tresilian was asked to come back a very short while later. What were to become the 4 cylinder BRM P25 engine and P25 car were originally his own designs, but as built were altered.
Tresilian's comments at Bristol on hearing that a fifth main bearing had been put in the P25 engine design by Berthon are best not repeated.
Interested in the application of Dunlop Maxaret aircraft anti-lock brake system for car use.
Tresilian admired Hooker, as, inter alia, Hooker had redesigned the supercharger on the Merlin and made it more efficient. There are stories that the original impeller and diffusor vanes were designed in part by Tresilian. Ellor had designed the successful blower drive [a very difficult task] and supercharger ram air intake.
Bristol projects included how to rationalise the manufacture of several gas-turbines including the marine Olympus and the Orion.
Tresilian is said to have designed or assisted in the design of a new 6 cylinder alloy car engine (for the Bristol car?), but this was cancelled due to the precarious financial position of the parent due to the icing problems on the Britannia.
Consultancy work for Rovers on the 2000 project, and for Coventry Climax on their racing engines.
Other consultancy was done, but so far no records have been found. His work and discussions with Ricardos, Alvis and, to a lesser extent, R.C. Cross of Cross Engineering remain a mystery.
He designed an advanced all-alloy very short stroke ohc 4 1/2 litre V8 engine in late 1959 for Armstrong Siddeley - presumably for the Star Sapphire replacement, but the company ceased making cars a few months later. Drawings of the engine will be made available on this site in due course.
Projects at the time of his death included:
A flying observation "van" for the Army which had reached wind tunnel testing (lift provided in some variants by 3 Blackburn gas-turbines driving two ~ 6' contra-rotating fans in the van floor);
A flying platform for short range battlefield missiles called the "flying pig" (a Pegasus, later BS100 [?], mounted on 4 wheels with a cab). Confusingly, the "flying pig" name was also used at times for the Army Van.
A V12 engine of about 4 1/2 litres extreme speed (probably with powered valve return) 11,000+ rpm lean burn engine to produce at least 1000hp for helicopter and tank use.
All of his projects died with him.
Other Matters
Tresilian wrote a long paper on the piston engine that for various reasons was not published by the Automobile Engineer as originally intended, but appeared - in parts - in Automotive Design Engineering in 1965. It was republished in a text book in the mid-80's. Another long paper, an introduction to suspension, which he completed a little time before he died, remains unpublished.
One of Tresilian's main interests at the time of his death was the design of a lightweight high performance saloon of reasonable price. The late Mervyn Cutler recalled hearing that Tresilian was trying to raise venture capital to further such work and look into light alloy cars.
Tresilian refused in both 1960 and 1961 Bristol Siddeley's firm request that he return to Coventry (the Armstrong Siddeley part of BS). His reasons can be all too readily understood. It is not yet known what capacity the company had in mind. He believed he could not refuse another time and knew that the third and final request would be made during 1962. As a result, he was discretely seeking independent consultancy work at the time of his sudden death in 1962.
The Missing Tresilian Manuscript
Tresilian wrote a long book between about 1959 and 1961 on design philosophy. There were at least five copies of the manuscript. Despite numerous searches, none can now be traced. All those who read the manuscript for the book describe it as both instructive and very amusing! Two engineers consider that certain other engineers might have had an interest in the manuscript's complete disappearance .... It can only be hoped that a copy will be found one day.
If you have any information, addition or correction about Tresilian and/or the missing manuscript, please do let me know. All information will be gratefully received.
© 1991, 1992, 1993, 2000 Richard Hodgson - may not be reproduced in whole or
in part without permission
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