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).
Development and testing of jacking systems for H.R. cars.
| Identifier | ExFiles\Box 139\2\ scan0120 | |
| Date | 8th August 1934 | |
| J 3117 To E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Sg.{Arthur F. Sidgreaves - MD} c. to Wor.{Arthur Wormald - General Works Manager} c. to Hy.{Tom Haldenby - Plant Engineer} c. to Pa.{Mr Paterson} c. to Bn.{W.O. Bentley / Mr Barrington} c. to Ev.{Ivan Evernden - coachwork} JACKING SYSTEMS FOR H.R. CARS. With reference to E.1/HP.30.7.34. We have, for a considerable time past, been experimenting with the Smith Jackall system and they certainly have by development improved its reliability and efficiency enormously. Originally they had trouble with the pressure flexes but now they use Lockheed brake hoses which appear to be completely reliable. The jacking system is so simple to operate that we think it will always be utilised when the car is washed and therefore will not be likely to deteriorate through lack of use. Incidentally, we have never experienced deterioration of the latest system though we have only had it on test about 6 months. The position with regard to the Jackall Jacks at the moment is that we have a set on the Phantom single lift type but they protrude too far over the front apron owing to the large lift required, and we are getting the makers to produce a double lift cylinder to overcome the difficulty. In the course of our tests we have jacked the car up on a 1 in 8 gradient and severely rocked it but without ill-effect on the jacking system. We have also left the car jacked up for 56 hours to test for loss of pressure which we found was negligible. We are getting a set of Jackalls fitted to the experimental coachwork car now at Hoopers, afterwards they can be tested on a trials car if this is thought to be desirable. With regard to weight, these add less to the unsprung mass than the present D.W.S. and we do not think that the design limit of weight reduction has yet been reached. Briefly, we think that if hydraulic transmission can be made sufficiently reliable for a braking system on cars such as the Morris and Hornet that are likely to suffer from continuous neglect, then it should be quite satisfactory for jack operation. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||