Specifications for a spring behind a carrier plate on a 20-EX model.
| Identifier | ExFiles\Box 13\7\ 07-page043 | |
| Date | 11th March 1930 guessed | |
| HS {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} K7480 G.73710. Spring behind carrier plate on 20-EX. Dia. of Wire. .092 Free Length. 1.100 Outside Dia. .487" Working Coils. 5 1/2 End Coils 2 69 lbs to compress to .850". Stress 15,400 O.K. Rm {William Robotham - Chief Engineer} | ||
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).