The build specifications for B.V. Gearbox No.12, its differences from No.11, and its intended vehicle.
| Identifier | ExFiles\Box 109\5\ scan0259 | |
| Date | 26th July 1939 | |
| 663 800b σ 428 To HPS {Horace Percy Smith - Experimental Factory Mgr} /RH. {R. Hollingworth} from Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} 6/MH. {M. Huckerby} 26.7.39. B.V. GEARBOX NO.12. We understand you will shortly be building this gear-box and should like its specification to be the same as box No.11 except that the 2nd. speed should not have anti-rattle plungers. The 2nd. speed cones should, of course, have the correct cam angles. Gearbox No.12 is, of course, required for 3.B.50, after which a further new box, No.13w will be required for Hs {Lord Ernest Hives - Chair} ' car. Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} | ||
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).