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 from John Marston Limited detailing manufacturing processes and quoting for Mark III and Mark V matrices.
| Identifier | ExFiles\Box 149a\2\ scan0207 | |
| Date | 26th June 1934 | |
| From: JOHN MARSTON LIMITED COPY 26.6.34 "Firstly we would explain that as a result of our discussions we understand that owing to failures which you have had on test you would desire a still more intense inspection to be made of the strip material which we use in the manufacture of your Matrices. As a result of this the manufacture of the strip has been investigated throughout the Works of our associated company I.C.I.Metals Limited, and at our Works, and in consequence it is recommended that you should consider the extra cost involved by an additional scarifying process to be introduced in the course of manufacture of the strip metal and by the introduction of two additional inspections on the surface of the finished material. In order to give you the cost of these processes we are submitting our quotation for Mark III Matrices exactly as at present supplied and also with the additional processing and inspection added. "Secondly we would mention that in quoting for our Mark V Matrices we are submitting our quotation based on three methods of manufacture. The first method is our normal method in which we use copper strip .005" thick for the waterway and .004" for the airways. The second method includes the tinning of copper strip in accordance with discussions which the writer has had with your Mr. Rowbotham, and the third method embodies the .006" thick waterways also tinned, and gives therefore the basis on which we have supplied samples again in accordance with the writer's last discussions with Mr. Rowbotham. "In all three methods we have allowed for the extra processing and inspection of strip which we understand you would desire to be included to ensure the very best quality material being used for your manufacture. "In the third place we would like to draw your attention to the fact that the radiating capacity of our Mark V block is greater than that of our Mark III Block and it is anticipated from the discussion which the writer has had with your Technical Department that smaller cores of our Mark V type may be recommended to replace the existing Mark III type as a result of tests which we understand are now in hand and for which we have supplied sample Mark V blocks of other dimensions than those now quoted for. (Continued) | ||