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 Ltd. discussing the initial test results and a sizing issue with three sample fan belts.
| Identifier | ExFiles\Box 135\1\ scan0103 | |
| Date | 21th December 1937 | |
| Rm{William Robotham - Chief Engineer}/Std.3/MH.{M. Huckerby} 21st. December 1937. Messrs. Ferodo Ltd., Chapel-en-le-Frith. For the attention of Mr. Longley. Dear Sirs, We have received the three sample fan belts which we ordered from you (as per British Goodrich mould No.242), and would advise you that the results obtained so far have been very promising. We have run one of these belts continuously for two hours under maximum load and speed conditions and the belt has not deteriorated in any way while the slip is only 3% - 4%. We shall of course, require to do a great deal more endurance running on this belt and shall not be able to complete this for another 2-3 weeks, but will acquaint you with the results as soon as we have them. One snag which we have run up against with the belt is that it is really too short. The dimensions which we gave you were based on the fan belts which we have already tested and which, made to those dimensions, were approximately correct for our pulley centres. When new they were certainly on the tight side, but after a few minutes running the tension was correct owing to initial stretch. With your belt, however, the new belt is so tight that it was necessary to alter the pulley centres on the experimental engine in order to avoid our stressing the belt initially, further the slackening off in tension after running is negligible . | ||