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).
Chassis frame failure on a Goshawk 11 during a bump test, with recommendations for material and design changes.
| Identifier | Morton\M1.5\ img010 | |
| Date | 1st December 1921 | |
| R.R. 235A (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. ORIGINAL R4/M9/12/21. To Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} Copy to:- BY.{R.W. Bailey - Chief Engineer} " H1. " CJ. Bump Test on Goshawk 11. Chassis. X4260 X4219 In reply to your Hs{Lord Ernest Hives - Chair}2/LG2.12.21., the broken and sagged frame suggest materials have not a sufficiently high EL. We must get better quality frames. I am also suggesting slightly increased thickness; those broken are .125, so I propose to increase this to .156 or slightly more, but we must have metal in a better state to resist fatigue, unless your tests are too severe, as the frame is a very carefully proportioned one and ought not to fail, but it is good to know where it will fail so that we can do something to improve the parts, and also demand metal in a better state to resist fatigue. I have come to the conclusion that the broken frame near the front dumb iron is caused by torsion in the spring being conveyed to the frame which is weaker in torsion than the spring. An increase in the thickness and quality of metal of the frame should make a definite improvement. R.{Sir Henry Royce} | ||