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).
Cause of 'booms' in Phantom II models, related to body and sub-frame construction.
| Identifier | ExFiles\Box 12\6\ 06-page046 | |
| Date | 27th April 1931 | |
| X7830 2 copies X7830. X7380. X634. To Hs.{Lord Ernest Hives - Chair} from Sg.{Arthur F. Sidgreaves - MD} re P.II. Booms. Sg{Arthur F. Sidgreaves - MD}11/E27.4.31 In a letter I have received from R.{Sir Henry Royce} he says: "It has occurred to me that we cannot take the rear feet away from a sub-frame carbecause it would jelly too much but we can take them away from a car in which the body is built on the frame. Also that the worst boomers are those which are built on the frame and are incurable by any other treatment. This, if true, would account for some of the differences of opinion because my car could not go on for a month here if worked hard with the rear feet deleted." I do not know why he is under the impression that the worst boomers are those which are built direct on to the frame, i.e. without a sub-frame, because so far as I know there are practically no cars which come under this heading so far as concerns P.II's, and as P.I's, which are free from this trouble, are all built direct on the frame, this conclusion seems all the more extraordinary. I hope you will enlighten me/him on this point when you meet. Sg.{Arthur F. Sidgreaves - MD} | ||