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 to Ferodo Limited regarding test results on servo linings and requesting alternatives.
| Identifier | ExFiles\Box 141\3\ scan0286 | |
| Date | 12th July 1934 | |
| x719 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}6/KW. 12th July, 1934. Messrs. Ferodo Limited, Chapel-en-le-Frith. Attention of Mr. Field. Dear Sirs, We have been continuing our tests on Servo linings and find that RAD.13 linings that have been heated to 700°F.{Mr Friese} till they cease smoking give a coefficient of friction of about .35 cold, rising slightly when hot. This of course is exactly what we want. We do not yet know how these linings will wear, but have already noticed that the joint has a tendency to break. Can you supply us with linings of similar characteristics due to a chemical treatment, as the heat treatment would not be easy on a production basis. Naturally any other lining you can offer us with a µ not less than .35 that does not fail when hot would suit equally well. Our tests on BZ, M.2 and VM.20 all show a considerable drop in output when hot. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||