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 Armstrong's Patents Co. Ltd. concerning damper casing modifications and metal specifications.
| Identifier | ExFiles\Box 152\2\ scan0046 | |
| Date | 7th October 1937 | |
| X 1293 Rm{William Robotham - Chief Engineer}/Les.13/WH. 7th. October 1937. Messrs. Armstrong's Patents Co. Ltd., Eastgate, Beverley, Yorks. For the attention of Mr. Bogg. Dear Sirs, Re Damper Casing FB.3095/6. We have just caught the damper casings in time to have the bore for the valve units modified to your print 416 - Z. We cannot understand the other modification which is marked in red on your print as 1.7/64 is the same as 1.109. With regard to the metal for these casings. Our first pair of casing will be R.R.50 and the remaining 5 pairs R.R.53.C. We are surprised to hear that you are having difficulty over getting R.R.53.C from the Birmols. We understand that High Duty Alloys now list R.R.53.C. If you cannot get R.R.53.C, it will be best to use R.R.53.B which is listed by Birmols. If your dies are made suitable for R.R.53.B you will have no difficulty with R.R.53.C as it is a still easier metal to cast. Our metallurgist strongly advise R.R.53.B in preference to P.2 alloy. Yours faithfully, for ROLLS-ROYCE LTD. | ||