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).
Drawing No. LeC.1106 for the 20 HP back axle tube, comparing it to the 40/50 HP model.
| Identifier | WestWitteringFiles\C\July1919\ Scan9 | |
| Date | 19th July 1919 | |
| To DA{Bernard Day - Chassis Design} from E.{Mr Elliott - Chief Engineer} Copy to C.I. " " BN{W.O. Bentley / Mr Barrington} " " [illegible] " " EFC. ORIGINAL RE 20 H.P. BACK AXLE. E1/G18/7/19. 2 V 349 3 We send you herewith drawing No. LeC.1106 shewing the axle tube for the above. The object of the drawing is to give you exact figures for the important dimensions on this piece, and to specify the degree of finish that is required inside and outside of the tube. The drawing also records a comparison with the 40/50 H.P. back axle tube, the modulus of which has been multiplied by a factor of .6 at all points along the length of the tube, and adjusted for spring and wheel tread centres so as to be comparable. The modulus curve given for the 20 H.P. is for the axle tube alone, no account having been taken of the fact that it is intended to use a tie rod. You will notice that the 20 H.P. modulus has been made relatively strong near to the wheel hub so as to easily resist shock due to the car skidding sideways and striking the curb, and any other shocks which impose a heavy bending moment on this part of the tube. Would you kindly put in hand the necessary detail work for ordering these tubes. E.{Mr Elliott - Chief Engineer} | ||