From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Letter from Avon India Rubber Co. Ltd. discussing the failure of a 6.50/16 tyre during high-speed testing and the development of a new tyre construction.
| Identifier | ExFiles\Box 156\3\ scan0113 | |
| Date | 24th April 1939 | |
| B31 ESTABLISHED 1885 SYMBOLS OF ENDURANCE CHAIRMAN MAJOR R.F. FULLER, J.P. DEPUTY CHAIRMAN SIR HERBERT E.{Mr Elliott - Chief Engineer} BLAIN, C.B.E., M.INST.T. JOINT GENERAL MANAGERS R.H. COMLEY. O.F. SWANBOROUGH. SECRETARY & ACCOUNTANT E.H. LOVELL, A.C.I.S. The AVON INDIA RUBBER CO. Ltd. Telegrams RUBBER MELKSHAM. Telephone MELKSHAM 120 (6 Lines). Codes A B C. 5th EDN., WESTERN UNION, BENTLEY'S & M.T. PRIVATE CODE. SERVICE DEPOTS. LONDON · BIRMINGHAM BRISTOL · MANCHESTER NEWCASTLE · GLASGOW BELFAST. LONDON OFFICE. MABLEDON PLACE, ST.{Capt. P. R. Strong} PANCRAS, LONDON, W.C.1. HEAD OFFICE & WORKS. MELKSHAM, WILTS. JGM/NAW. Your Ref: Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}5/MH.{M. Huckerby} 24th April, 1939. Rolls Royce Ltd., DERBY. Attention:- Mr. F.J. Hardy. Dear Sirs, We have to thank you for your letter of 20th April. We have examined the 6.50/16 tyre which "threw its tread" at 100 m.p.h. on your test drum. There are no signs of faulty workmanship. Although it is possible that at 100 m.p.h. on a test drum running indoors our new tyre might be more likely than competitive makes to throw its tread because of its greater tread thickness, it is nevertheless our view that up to speeds of 90 m.p.h. on the road no tread separation will occur. We have just completed an extensive programme of tests on giant tyre breaker constructions, drum tests at moderate speeds at Melksham having been followed by road tests in Texas on trucks averaging 60 miles per hour. Under the latter conditions, because of the thickness of giant treads and the higher atmospheric temperatures, a great deal of heat is developed at the junction of tread and casing and with prior constructions of all makes, tread separation was the main cause of tyre failure. During these tests a new type of breaker construction was developed, was proved highly superior to earlier constructions and was adopted for all our large size giant tyres. In the light of your letter of 20th instant, we think it desirable to adopt this construction for our new tyre in your size and we will despatch 4 - 6.50/16 tyres of this type to Brooklands in time for your test there on Wednesday, 26th instant. Yours faithfully, THE AVON INDIA RUBBER COMPANY LIMITED. J.{Mr Johnson W.M.} G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Mackay DEVELOPMENT MANAGER and CHIEF CHEMIST. | ||