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 Ferodo Limited discussing the friction and wear characteristics of brake lining materials.
| Identifier | ExFiles\Box 140\4\ scan0151 | |
| Date | 24th January 1938 guessed | |
| From FERODO LIMITED. Sheet No. 2 A.{Mr Adams} F.{Mr Friese} Martindale Esq., Messrs. Rolls Royce Ltd. As regards the VG.91 already sent to you, I think it very probable that you will find it possesses the second of the two qualities of friction defined above because it has a coefficient of friction rising with temperature - I think it exceedingly probable that we shall find that if a lining is to have a coefficient decreasing with speed then equally it will have one rising with temperature; I do not believe we can dissociate temperature from speed. Now as regards the copy of Thermoid D35IH, I asked Mr. Harrap to explain when he handed over these linings that the slightly darker colour of our material was due to the fact that we had comminuted one of the ingredients to a much finer state than it is present in the original, resulting in a generally darker uniform colour as distinct from a speckled. I have examined the behaviour of this lining most carefully and its μ characteristics reproduce those of the original to an extraordinary degree. I am therefore hoping it will behave as well as the American lining whilst still conforming to our ideas of durability. Again many thanks for your letter and, if I may, I would like to congratulate you upon the originality and the importance of the principle contained therein. Yours truly, FERODO LIMITED Mongley Chief Chemist & Director. | ||