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).
Specification memo regarding the 'Shore Durometer' hardness for rubber parts, including the Wraith front suspension buffer.
| Identifier | ExFiles\Box 154a\4\ scan0055 | |
| Date | 25th January 1938 | |
| To By. {R.W. Bailey - Chief Engineer} from Rm {William Robotham - Chief Engineer} /Les. ? 1306? Rm {William Robotham - Chief Engineer} /Les.7/MH. {M. Huckerby} 25.1.38. SPECIFICATION FOR RUBBER PARTS. We have asked on several occasions that our detail drawings for rubber parts should state the "Shore Durometer" hardness number and limit. For a limit we should give a possible variation of five points. At the moment we invariably get our first samples made with the incorrect hardness of rubber. We have just been in communication with the Firestone Tyre & Rubber Co. Ltd. with regard to a quotation for Wraith front suspension buffers G.W. 1596 and G.W. 1669, and they have asked us what we mean on our drawing by G.W.R. quality and what durometer we require. It appears that G.W.R. is Dunlop's code for a particular mix of rubber produced for some rear axle buffers on Phantom I. As long as the drawings state the durometer No. there is no need for further particulars for the rubber. We consider that Wraith front suspension buffer should be "Shore Durometer 60 - 65". Rm {William Robotham - Chief Engineer} /Les. | ||