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).
Model crank tests detailing inconsistent results and modifications to the testing procedure to induce failure.
| Identifier | ExFiles\Box 63\4\ scan0117 | |
| Date | 19th May 1930 | |
| To Rg.{Mr Rowledge} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X4499 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}3/MJ.19.5.30. MODEL CRANK TESTS. Further to Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}3/MJ.13.3.30. We are not meeting with very consistent results on these tests. It will be recollected that we increased the moment of inertia of the flywheel 30% to ensure that the shafts would break within a reasonable period. We then ran a crank to DES.989 (Webs .295" Thick) for 10^7 reversals and this did not fail. It being imperative to obtain failure in order to get any comparison, we have now decided to make our standard test 400 R.P.M. with the inertia increased to 19.55 lbs. ft^2. The following are details of the tests that we have carried out on two shafts that had been subjected to torsion test, we used these while we were waiting for further new models. DES.995. Model of DES.989 Crank. Webs .295" Thick. Previously subjected to Torsion Test. Flywheel R.P.M. 300 Stroke 6". Inertia increased by 30%. Total Time run 275 Hrs. 55 mins. Total reversals 10,000,000. Average R.P.M. 302. Shaft unbroken. R.P.M. increased. (over) - | ||