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).
Axle weight calculations and comparing the weight of the EAC.7 transmission type against the standard 40/50 model.
| Identifier | ExFiles\Box 12\2\ 02-page023 | |
| Date | 8th November 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} Y7350 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG8.11.27. EAC.7. AXLE WEIGHTS. X.8840 X.7350 Further to our Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG2.11.27. The weight of the universal joint was inadvertently omitted from the sphere. In addition the suspension and torque rods of the sphere should be included as being necessary adjuncts to the present 40/50 type of axle control. As the spare wheel carrier will very shortly be standard on the 40/50, it is only fair to include the frame extensions necessary for this. Weight to be added to 40/50 Axle control. Universal joint............ 8.4 lbs. Sphere mounting and control rods................ 6.1 lbs. Spare wheel carrier frame extensions (2)........ 8.0 lbs. ----------- 22.5 lbs. ----------- Therefore, including these particulars, as the two cars stand at present, the EAC.7 type of transmission shews a saving in weight of 8.5 lbs., instead of an increase of 14 lbs. as previously given. In addition, as pointed out by DA.{Bernard Day - Chassis Design}, there is clearly no fundamental reason why, for a given rating and maximum deflection, the semi-elliptic springs should be any heavier than those of the 40/50. With springs of the same weight, which we have not got at present, EAC.7 type of contd :- | ||