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 concerning the effect of water on brake linings, detailing results from laboratory and road tests.
| Identifier | ExFiles\Box 141\3\ scan0063 | |
| Date | 18th July 1931 | |
| X3409. SOCIETY OF MOTOR MANUFACTURERS & TRADERS LTD BRITISH BELTING & ASBESTOS LTD NATIONAL SCHEME FOR DISABLED MEN HALO NON-METALLIC CLUTCH AND BRAKE LININGS SCANDINAVIA COTTON CONE LINERS AND BONNET LINING MINTEX STANDARD WOVEN TYPE CLUTCH & BRAKE LININGS Technical Representative ERIC D.{John DeLooze - Company Secretary} DALMAINE Ullenhall. Nr. Henley-in-Arden. WARWICKSHIRE. 18/7/31. W.A.Robotham Esq. Messrs.Rolls Royce Ltd. DERBY. Dear Sir. Further to my letter of the 25th ult. on the subject of the effect of water on brake linings, we hope to let you have some information within a fortnight. I have just returned from our Works and they are now carrying out a series of road tests. A definite flow of water is being fed into the drums from a tank carried on the car, and the deceleration noted for various materials. Some time ago we made some laboratory experiments on the effect of water. It was first ascertained how much water could be retained in the drum by centrifugal force, and that amount of water was injected for each test. The results shewed that various types of linings with dry frictions of from 0.35 to 0.55 all dropped to from 0.08 to 0.12 when wet. There is, however, a difference in the rate of recovery and there the resin types of linings shew to advantage. Of course the resin lining with its higher dry friction will shew a greater variation, but its wet friction is no lower. This is a very old question, but coming from you I have prevailed upon our Works to carry out a series of road tests and so definitely clear up the point. I am sorry about the delay, but Mr.Sisman, our experimental engineer has been on the Continent. He has now returned and no time is being wasted. Yours faithfully, Dalmaine. | ||