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 detailing test results of sample oil coolers and subsequent production and replacement requirements.
| Identifier | ExFiles\Box 131\5\ scan0010 | |
| Date | 9th November 1937 | |
| 1114 November 9th 1937. Rm{William Robotham - Chief Engineer}/Std.9/AP. Messrs John Marston Ltd., WOLVERHAMPTON For the attention of Mr.Dunn. Dear Sirs, We have now completed tests on the five sample oil coolers of the latest type which the writer brought back from your works. The results, which are shown on attached sheet were very satisfactory. After pressure testing to 200 lbs/sq.in. 1000 times, four of the coolers were subjected to a pressure which was gradually raised until failure occurred - the failing pressures being as shown. Cooler No.5, showed a slight leak at 250 lbs/sq.in. through a pore in the bottom plate itself, but this was disregarded and the pressure raised until failure occurred at a joint surface. The standard of solder bond observed by sectioning of the cooler was excellent in all cases. It will be noticed that the three coolers failed at the same spot i.e. where the division plate prevents a perfect metallic contact between the tubes and the bottom plate. We think therefore, that no trouble whatever should be experienced with future coolers if the standard of solder bond, workmanship, etc. evident in the five sample coolers is maintained. As discussed with you, we therefore require you to make all future coolers, both new and reconditioned in this manner. As new and reconditioned coolers will be indistinguishable and in fact identical, we would suggest that you send us an adequate supply of coolers to cover both our production and replacement requirements using either parts from the old coolers returned to you or new parts according to your convenience. To cover our production and replacement requirements we require 30 coolers per week until the reconditioning is finished - 4 coolers per week for production and 26 coolers per week for replacements. continued | ||