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 concerning the design, testing, and delivery of an Oil Cooler.
| Identifier | ExFiles\Box 131\1\ scan0255 | |
| Date | 15th December 1936 guessed | |
| From JOHN MARSTON LIMITED. To Messrs. Rolls-Royce Ltd., Derby. (CONTINUED). We should like to point out that the weight of an Oil Cooler of the proposed design would be about 2 ounces heavier than one of existing design, an increase of some 5% only. The sample submitted to you however, for trial will be found to be somewhat heavier than the estimated weight. This is due to the extra quantity of solder picked up, special tools for top pressing and side plates not having been made. The Oil Cooler we have assembled for trial has new design of top and 16 w.g. side plates. It has passed the usual pressure tests. No distortion of the top plate occurred. Bulging of the side plates at 200 lbs per square inch pressure was very small. This cooler fits snugly into the aluminium casting which we have at out works. It will be noted one layer of tubes had been removed to counteract the increase in depth of the top pressing. This keeps the overall depth of the Cooler about the same. We expect to despatch this Cooler on Thursday. The writer wishes to correct his statement when in conversation with Mr Steadman last Friday, concerning the new design of top pressing and its method of assembly. The unions are not sweated to the steel plate as explained but spot welded. The whole is then inserted into the brass pressing and dipped in a solder bath, thus making a very rigid structure. The square ended unions which were promised over the week end have not yet arrived. However as you have decided to fit the other design of cooler to your test car, we assume you are in no hurry for a specimen of the former design (to your drawing). The two Oil Coolers numbers E.4. and E.8 were brought back to these works by the writer. We shall await your instructions before proceeding with their Repair. Yours faithfully, For JOHN MARSTON, Limited, A.A.H. Meats | ||