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).
Test report on a new reinforced steering pivot, including failure analysis and remarks.
| Identifier | ExFiles\Box 2\B002_X168\ 00000001-page076 | |
| Date | 4th April 1918 guessed | |
| A/EH1/L.S413 (contd) -3- Test No.16 New reinforced steering pivot This was run for 1800 mins. and had 630,000 complete reversals, there was no sign of a crack. During the test we broke 4 steering arms. To break it we speeded up the rig from 350 to 450 reversals per min. After 90 mins of this it cracked and in 190 mins broke. We broke two more arms in this last test. I am sending the fractured pivot to Mr Royce, also one of the present type fractured, because they break in a slightly different way to the old ones. Remarks on the Tests There is a big difference in the time taken for pivots to break, we imagined at first that this might be due to the different mileage they had done on the road but we find the same variation in new pivots. During the tests we have broken 4 steering arms (this does not count those broken with the latest reinforced pivot). One lasted 164 hours, another 7 hours, another 95 hours, another 3 hours, they have all gone in the same place. The spring buffer on this test does not show any advantage. We broke several springs. We used the springs out of the side steering rod and rigged up a similar arrangement to that. This test shows up the necessity to avoid the sharp edges on the pivots where the stress comes as suggested by Mr Royce (see test No.7) | ||