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).
The Goshawk 11 front springs, comparing the performance of parts from suppliers Firths and Woodheads.
| Identifier | ExFiles\Box 49\3\ Scan150 | |
| Date | 30th August 1922 | |
| BA. from BY. {R.W. Bailey - Chief Engineer} c. Hs. {Lord Ernest Hives - Chair} X4261 BY15-P30.8.22. GOSHAWK 11, FRONT SPRINGS. The springs which were supplied to us by Messrs. Firths actually had top plates which were only .225 thick (unground). Mr Hives has reported on these as tried out on the bumping test and informs us that they give approximately the same hours in time resistance to breakage on the bumper as the Woodhead. It would appear therefore that the thinning down of the plate has not affected the life of the spring, although we agree that the experiment has been masked by the way that the springs which are being compared are made by two different makers under different conditions. In regard to the Woodheads springs, we are not specifying grinding on any of the rubbing surfaces, and therefore the top plates, in common with the lower plates, are in the as rolled condition, except that on the edges of the plate they are ground to eliminate any possibility of slight cracks being the cause of trouble by forming a starting point for fatigue effects. BY. {R.W. Bailey - Chief Engineer} | ||