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 development and calculation methods for 'Goshawk II' road springs.
| Identifier | ExFiles\Box 49\3\ Scan055 | |
| Date | 19th September 1921 | |
| To R. {Sir Henry Royce} from DA. {Bernard Day - Chassis Design} Copy to WGT. HS. {Lord Ernest Hives - Chair} X4261 ORIGINAL RE "GOSHAWK II" ROAD SPRINGS. AXG1 19/9/21. RECEIVED X4261 X2678 I have now looked into the records of the work these springs, and should very much like to be allowed to report as follows:- When I left Derby we had instructed a pair of experimental 1100 lb rear springs and 630 front springs which had been calculated on the method of Mr. Landow, but in order to reduce the already very large numerical work, we had decided to neglect the tapering of the leaf tips (we believed we might do this without serious error) Before I left Derby, we had modified and amplified Mr. Landow's method, because there were some points about it which we thought were not accurate enough, and I left Mr. Stott to work out all the springs on this new method, but not to place any more springs on order until the arrival of the experimental springs. In due course he reported that these had come in and that while the front spring had come out reasonably closely to drawing, the rear spring was too stiff. This was investigated and the conclusion some to that the principal reason for the difference was the neglect of the tapered ends. We proceeded now to take account of the tapered ends, in spite of the increase of numerical work, and ordered another pair of specimen springs already calculated on our improved method, with the result that in this case the springs came out as nearly to drawing as can be expected (about - 35 lbs av.) In fact it was shewn that had the springs been exactly to drawing they would almost certainly have given their exact load. When Mr. Stott reported this to me, and said that BY's department were pressing for more springs, I immediately instruct to issue these springs already calculated on our method, and | ||