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).
Weight analysis comparing the B.III and B.V. overdrive gearboxes.
| Identifier | ExFiles\Box 99\4\ scan0245 | |
| Date | 30th December 1940 | |
| To: Rm.{William Robotham - Chief Engineer} c. Ev.{Ivan Evernden - coachwork} Gearboxes. B.V. B. V.{VIENNA} GEARBOX WEIGHT. 428 We have compared in detail the weight analyses of the original B.III gearbox and the present all helical B.V. overdrive box with the following results :- Weight analysis figure for B.III box. 81. 10½ " " " " B.V. " 93. 13½ The servo drive worm is included in the gearbox on B.V. but is part of the brake system on B.III. The correct comparative figures are :- B.III. 81 10½ B.V. 93 3½ Increase 11 9 This increase is made up as follows :- Increase of weight of gearbox parts. 1st.M. shaft bearing 1. 3. 2nd.M. outer shaft & gears 11 2nd.M. inner shaft 5 Reverse outer shaft & gears 2 9¼ " inner shaft 1 6 Gearbox casing 1 9 Miscellaneous 8¾ Total weight increase of 8 4 box and mechanism Increase of weight due to additional engine mounting parts. Torque reaction support 2 8½ bracket. Fore and aft tie rod 12½ bracket. Total 3 5 Box total as above: 8 4 Grand Total: 11 9 We consider that the true gearbox weight increase of 8 lbs. 4 ozs. is justifiable as we cannot think of any lighter way of obtaining the same results. Rm{William Robotham - Chief Engineer} FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||