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).
Manufacturing issues with liners and drums, including material expansion and design failures.
| Identifier | ExFiles\Box 121\1\ scan0348 | |
| Date | 31th October 1940 guessed | |
| 6-ctd) a steel one .100 thick. 7) We ran into a little trouble with liners turning at only .090" thick instead of the designed .100". We forgot that with an interface of .026", the alum. expands & the iron is compressed, about .010 it appears. We altered the dimensions accordingly. A liner .090" thick gives little latitude for drum wear. 8) We ran into serious trouble with "ageing" of aluminium & permanent expansion of .012" per 12" after casting. The first lot of drums aged naturally owing to colossal time of manufacture. The next lot were made in a hurry, & were a frightful failure - lack of interface fit, liners came loose. We instituted an "ageing" heat treatment of the cases before turning. 9) Ev{Ivan Evernden - coachwork}, for his convenience, designed a drum with the outside web too far in, like this:- [Diagram showing a component cross-section labelled 'WRONG'] [Diagram showing a modified component cross-section labelled 'RIGHT'] They all burst. We never did it again. This edge must be continuous. No nicks. | ||