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).
The limitations of the standard Dunlop Jack and the reasons for not favoring the Jack-all system.
| Identifier | ExFiles\Box 26\3\ Scan060 | |
| Date | 28th February 1930 | |
| -2- Hs{Lord Ernest Hives - Chair}/AJL.l/ML.28.2.30.Contd. absolutely necessary. In this case it is necessary to put the jack under the font spring and use the screw extension. This procedure is necessary with the Dunlop Jack at present standard; we use it because we cannot get a better one. It was standardised in 1928 for Phantom l and owing to the larger road wheels and the then standard front axle, it complied with our requirements. We do not like jacking off the springs, but it is the only solution until we can obtain a jack of less minimum height. With regard to the Jack-all system, we did not know that this was ultimately fitted to H.R.H. Prince of Wales' car. The chauffeur wrote to Sales about the system in May 1928 and we told sales we had not actually tested the system but that from the description of it we were not in favour of it for several reasons :- (1) Increase in unspring weight (5 lbs. on each axle). (2) The difficulty of retaining oil tight feed 'lines' from the chassis to the axles. (3) Oil leakage. (4) Reduction of ground clearance. The system was then marketed by the Mayfair Four Wheel Hydraulic Jacks Ltd., but it is now marketed by S. Smith & Sons. Possibly it may have improved since that date. H.R.H. Prince Wales' Phantom ll car is not fitted with the Jackall system. We shall be glad to hear that you can persuade the jack makers to supply something that is satisfactory. Hs{Lord Ernest Hives - Chair}/AJL. | ||