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).
The quality testing of Dunlop scuttle isolation rubbers, finding them variable and recommending Avon rubbers as a preferred replacement.
| Identifier | ExFiles\Box 53\4\ Scan236 | |
| Date | 1st August 1930 | |
| X 4613. To By.{R.W. Bailey - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/AJL. c. MX.{John H Maddocks - Chief Proving Officer} Hs{Lord Ernest Hives - Chair}/AJL12/AD13. 8.30. SCUTTLE ISOLATION RUBBERS. We have booked out of production stock, for the purpose of testing hardness, four Dunlop hard scuttle isolation rubbers F.50729. These four rubber bushes all vary considerably both in size and quality. The maximum variation in the outside diameter dimension is .100", one of them is .020" thinner than the other three and the diameter of the bolt hole varies .050". The quality of the rubber varies enormously; when tested by compressing them with a 50 lb. weight, the compressions were as follows .012", .007", .014", .005". In view of this and in addition because none of these rubbers are the same quality as the sample we originally standardise we should strongly advise obtaining these rubbers from some other source, Avons for preference. We have examined the sample Avon rubbers sent along under cover of By/EM17/J22. 7.30, the quality EL.191 meets our requirements for the job and we should recommend that it is adopted to replace the present soft Dunlops as soon as supplies can be obtained. It appears necessary that all rubbers should be tested when received to ensure that they are correct to our requirements. We will, in the course of the next few days, outline what we think is a reasonable test for them. Hs{Lord Ernest Hives - Chair}/AJL. | ||