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).
Car springing, periodicity calculations, and passenger comfort for different car models.
| Identifier | ExFiles\Box 67a\1\ scan0056 | |
| Date | 6th January 1926 | |
| - 3 - 5. In regard to 11-EX. the springing of this car was in no sense special. It was passed through our springing Dept. and springs called for in the ordinary way, based on our usual formula. The springing of this car, in common with all others where correct weights are given both for the body and passengers to be carried, has worked out satisfactorily in practice, proving that when we are provided with the correct estimate of the body weight and the passengers to be carried, no complaints in regard to springing arise. 7. In regard to the periodicity of springs, referred to under Heading 7, the facts as stated in CWB1/EP.{G. Eric Platford - Chief Quality Engineer}5.1.26. are incorrect. The period of the 40/50 rear springing is very much slower than that of the 20 HP. The actual figures are as follows:- a/- 40/50 with full load - Calculated period 66 complete oscillations per minute. b/- 20 HP. with full load - Calculated period 85 complete oscillations per minute. c/- Actual periodicities of 40/50. fully loaded - 72 to 75 per minute. d/- Actual periodicities of 20 HP. fully loaded - 92 to 96 per minute. from which it will be clear that it is not the periodicity of the rear spring which is the cause of the complaint. In regard to paragraph 2. of Item 7, I have never expressed the opinion that the 40/50. springing is better than the 20 HP; my impressions are the other way; as to just why this difference arises appears to be where CWB. and myself part company, but there is no difference of opinion as regards the actual impression of the springing on a passenger. In regard to paragraph 4. of Item 7, the point in this connection in my previous memo was to show conclusively that we could not change to a lighter spring on our present range without seriously endangering the reliability of the spring, a point which I think I clearly demonstrated by giving actual stresses in thick plate springs under which they fractured, in the first place, and secondly, by | ||