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).
Performance and characteristics of D.W.S. permanent jacks on 40/50 HP and 20/25 HP chassis.
| Identifier | ExFiles\Box 139\2\ scan0070 | |
| Date | 26th March 1934 | |
| -2- Hs{Lord Ernest Hives - Chair}/Bwg.{J. C. Bowring}5/KW.26.3.34. D.W.S. Jacks! The above permanent Jacks as standard on 40/50 HP. and 20/25 HP. Chassis are generally the most satisfactory we have found up to date. One Jack is fitted centrally under the front axle and two Jacks directly under the rear axle; thus we get a direct lift. This system is certainly more fatiguing to operate than the Jackall, although a two-speed handle is introduced on the 40/50 HP. to lessen the effort in raising and lowering the car. It is difficult to lessen the friction in these Jacks as the majority is due to the weight of the car taking up any small play which may be in the working parts of the Jack. We can however try a still faster operating thread on the main shaft. When we try out the Jacks they are new and all parts are naturally stiff and no doubt when the Jacks have been used they will lose this stiffness. Hs{Lord Ernest Hives - Chair}/J.Bowering. | ||