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).
Results and analysis of vehicle frame stress tests.
| Identifier | ExFiles\Box 119\2\ scan0003 | |
| Date | 12th September 1913 | |
| X.1331 Mr Johnson. Mr Royce. September 12th. 1913. Wor{Arthur Wormald - General Works Manager}/EH6/L12913. Re Frame Tests. We have broken another frame, I am sending the piece to Mr Royce. It was a 1700 series with 7.25" set on the front horns, and old type cross member rivetted. 20 mins. Sheared Spring Bolt. 40 " Broke Steering arm pivot to side rod. 70 " Broke steering arm cross rod. 185 " Top leaf of spring. 210 " Frame. This frame had more rigid front horns than the one we broke yesterday, due to them having 1.00" less set down and the metal being .030" thicker, it broke in just over half the number of bumps. Although this test cannot be taken as conclusive it looks as though making the front more rigid will tend to break the frame quicker. We notice that up to the present our tests show that the cross member always cracks on the near side (weakest spring) but the frame breaks on the off side strong spring. We have not had a frame break on the same side as cross member is cracked. We did not renew the cross member when it cracked on this test but ran on with it until the frame went, the rivets held remarkably well and did not shake loose at all. We are pushing forward with a test on a heat treated frame. I think it will be necessary to test | ||