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).
Blueprint for a 40mm barrel with testing instructions and material specifications.
| Identifier | ExFiles\Box 176\3\ img215 | |
| Date | 19th July 1940 guessed | |
| ORDER No 138056 138059 3 DIA 4" 59.2" 85" ROUGH M X CUT TEST & INSPn E.S.C. TENSILE & IMPACT FROM BREECH END OF EACH BARREL. BREECH & MUZZLE END OF BARRELS TO BE. BRINELLED. THE BRINELL ON MUZZLE END SHOULD BE WITHIN 25 POINTS OF BRINELL ON BREECH END. NOTE TEST MATERIAL HAS BEEN PROVIDED ON BREECH A B C ROLLS ROYCE 40MM BARREL - 30 THUS N°S 4 - 30 THUS N°S 4 70 TON ULT. DIMENSIONS ARE IN INCHES. NO SHARP EDGES OR CORNERS TO BE LEFT. | ||