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).
Comparison document outlining the pros and cons of fitting the Jackall jacking system to the chassis.
| Identifier | ExFiles\Box 139\2\ scan0069 | |
| Date | 26th March 1934 | |
| To Hs.{Lord Ernest Hives - Chair} X31/7 Hs{Lord Ernest Hives - Chair}/Bwg.{J. C. Bowring}5/KW.26:3:34: Car Jack Comparisons. Jackall Jacking System. Whilst the above system is efficient, we give below reasons why it cannot be satisfactorily applied to Rolls-Royce chassis. At present there is only one way in which the rear Jacks can be fitted to the rear axle, and that is by a clamping bracket round the axle tube. This is not at all satisfactory owing to the fact that the bracket decreases buffer clearance, also one does not get a direct lift under the axle when jacking up. We are at present trying to find a suitable fitting for this scheme though with our rear axle as it is, we have not much hope without re-designing the Jacks to fit into the available space. The front Jacks are fitted one either end of the axle and the tops have to protrude through the front apron owing to their length. Also we think that they may have some effect on the steering. We recently tried a set of Jackalls, leaving them jacked up for approx. 17 hours, during which time they maintained their pressure. They are lighter and easier in operation than the D.W.S. The main cylinder is situated under the floorboards on the near side front, and accessible through a hinged lid{A. J. Lidsey} in the floorboards. They are of course much more expensive than the D.W.S. One advantage in this system is the fact that either two or four Jacks can be operated at one time, whereas our standard type have to be operated individually. Messrs. Smiths are fitting their latest type to 20-EX soon after Easter, we shall then be able to see whether or no the front Jacks affect the steering in any way. | ||