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 John Marston Ltd. detailing the fatigue test results of an experimental oil cooler.
| Identifier | ExFiles\Box 131\1\ scan0329 | |
| Date | 13th September 1937 | |
| 1114 Rm{William Robotham - Chief Engineer}/Std.3/MH.{M. Huckerby} 13th. September 1937. Messrs. John Marston Ltd., Wolverhampton. For the attention of Mr. Dunn. Dear Sirs, We have returned to you the experimental oil cooler which you sent us, which we have fatigue tested and which has failed after being subjected to alternate pressures of 0 and 200lbs/sq.in. It withstood 302 reversals before failure occured at the junction of the tube ends towards the centre of the matrix (marked with yellow paint). This test has not been of much value since the failure is not at the strengthened points. We would like you to repair the cooler by re-dipping, and if possible fit the thicker side plates about which we have already written you. The test will then serve both as a test of new construction and of efficiency of re-dipping process. With regard to the used hand soldered oil cooler which you have converted to dipped type. We have tested this by subjecting it to pressures of 0 and 200lbs/sq.in. 120 times, it then failed at one edge as shown by yellow paint on cooler (which we are returning for your examination). In view of the fact that two of your coolers made by dipping in the first place, i.e. new coolers, have withstood 0 to 200lbs. 500 times each without failure, it does | ||