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).
Sketch showing a crack in the crankcase of a B.7 unit after 17 hours of operation.
| Identifier | ExFiles\Box 86\2\ scan0104 | |
| Date | 23th October 1933 guessed | |
| B.V. 9 CRANKCASE CRACKED HERE OFF SIDE OF ENGINE DIAGRAM 3 SKETCH SHOWING CRACK IN CRANKCASE OF B.7 UNIT AFTER 17 HOURS | ||