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 Humber Limited to W.A. Robotham discussing crankshaft damper experiences and materials.
| Identifier | ExFiles\Box 132\2\ scan0175 | |
| Date | 2nd September 1940 | |
| 1116 TELEGRAMS & CABLES: HUMBER, COVENTRY TELEPHONE:- 5041 IN REPLY KINDLY QUOTE: AGB/EN BY APPOINTMENT TO THE LATE KING GEORGE V.{VIENNA} CYCLE MANUFACTURERS HUMBER LIMITED COVENTRY LONDON SERVICE STATION CHASE ROAD WILLEDEN, N.W.10 2nd September 1940 W.A. Robotham Esq., Messrs Rolls-Royce Ltd., Derby. Dear Mr.Robotham, I am very interested in the contents of your letter of the 29th ultimo which came to hand this morning, and note your experiences with a crankshaft damper of the Humber type. The LANCHESTER damper located in the timing case should undoubtedly give consistent results, but we have had no trouble over a long period of time with the damper we are fitting today. This may not necessarily be due to the material used in the damper, although I believe it plays a large part. Our material, which is of an ordinary commercial grade, is Ferodo S6416 in the discs, and Ashdown's laminated bakelised fabric in the damper bush. We fully expected trouble of the type you experienced in the early experimental days and had this occurred we would have used in production, for the discs and rings, a material which we proved was more impervious to climatic conditions - namely, "Tufnol" by Ellison Insulators, Perry Bar, Birmingham. I believe the particular brand of this material in which we were interested was called 'Carp'. Two other factors enter into this matter - (a) The protection against ingress of foreign matter, including water, which I know need not be emphasised, and (b) The amplitude of the torsional oscillations in the undamped crank. | ||