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).
Remark regarding the production of pip locking piston rings for pistons X.294.
| Identifier | ExFiles\Box 16\1\ Scan128 | |
| Date | 10th June 1913 | |
| x741 Rec. 10-6-13. Piston Rings. (Pip Locking) PISTONS. X.294. F.H.R's remarks re AW/SM15/L22413. "Going well, do not think we can do better than these, make tools for quantity, perhaps G&B slotter would help, pip slightly under." | ||