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).
Pros and cons of different jacking systems for the Spectre model.
| Identifier | ExFiles\Box 139\2\ scan0289 | |
| Date | 18th June 1935 | |
| SECRET. To E.{Mr Elliott - Chief Engineer} from Sg.{Arthur F. Sidgreaves - MD} Copy to Wor.{Arthur Wormald - General Works Manager}Hs.{Lord Ernest Hives - Chair} BY: Jacking System of SpectreCodename for Phantom III. Sg{Arthur F. Sidgreaves - MD}9/m18.6.35 I am in receipt of E.4/HP.14.6.35. In the second paragraph you say that the E/Lid.{A. J. Lidsey} memo. shows that you have two satisfactory schemes, one with DWS screw jacks and the other with hydraulic operated jacks, but on reading the memo. it seems to me that the first page rather condemns the DWS screw jacks. I do not understand why you are troubling about trying to lift the two back wheels together with the complication entailed, "for simultaneous operation by a cross shaft passing through the rear tubular cross member and the minimum of effort in raising was ensured by the use of bevel gearing mounted on simple needle roller bearings with ball thrusts for carrying the reaction of the loads so that only the inefficiency of the screw would remain." I seem to remember pointing out once before that we did not want the two back wheels lifted simultaneously. We have not had it on the Phantom. We see no advantage but a definite disadvantage as it would be difficult to hold the car in position when on anything but dead level ground and the complication and cost of doing it are unnecessary. The hydraulic system to which you refer as being satisfactory is presumably the DWS one which from the information given appears to be in the experimental stage. I think we might usefully discuss this matter when I am at Derby next week. Sg.{Arthur F. Sidgreaves - MD} | ||