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).
Laboratory report page with photographs showing the fracture and inner surface roughness of a 9hr spring.
| Identifier | ExFiles\Box 119\1\ scan0203 | |
| Date | 11th May 1939 | |
| ROLLS-ROYCE LABORATORY REPORT: Tl./EJW. S/JM.{Mr Morley} 11.5.39. M.1840/1. X 1 1/2. Appearance of fracture of 9 hrs. Spring. M.1840/2. X 5. Roughness on inner surface of 9hr. Spring. | ||