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).
Expressing concern about high stress levels on the front suspension of the Wraith II model.
Identifier | ExFiles\Box 8\7\ 07-page07 | |
Date | 9th June 1936 | |
To E.{Mr Elliott - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Lec.6/JH.9.6.36. Wraith Front Suspension N.Sch. 4818. Although we are much in favour of the general effort which is being made to reduce weight on Wraith II we are rather frightened that the stress in the front suspension will be very high. We understand that the space available for the springs will necessitate stresses as high as those of Phantom III for 950 lbs. load. As in certain cases we need 900 lbs. springs to give the correct buffer clearance, on the present 25 HP. we do not consider 950 lbs. is sufficient for Wraith II with its revised weight distribution. Our car 18-G-IV. has 925 lbs. springs fitted at the present. It appears therefore that the spring stresses will be even higher than those of Phantom III. We are told by the English Steel Corporation that the Vauxhall Dubonnet suspension springs do not exceed a corrected stress of 90,000 lbs/sq.inches. at choc length. Ph.III max stress is 136,000 lbs/sq.inches. In view of the fact that the front road springs poundage of all our chassis has increased as soon as a new model has reached production, it would appear foolish to limit the stresses in the springs and levers so that a load in excess of 950 lbs. is impracticable. Hs{Lord Ernest Hives - Chair}/Les.{Ivan A. Leslie} | ||