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).
Summarizing the experience with hydraulic shock dampers on Phantom I and Phantom II models.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan001 | |
| Date | 2nd December 1930 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Ra. c. to Er. c. to Da.{Bernard Day - Chassis Design} c. to Ev.{Ivan Evernden - coachwork} EP.{G. Eric Platford - Chief Quality Engineer} ORIGINAL 1235. HYDRAULIC SHOCK DAMPER. In view of the fact that these are in process of re-design, we think it may be useful to summarise our experience of the hydraulic damper. (1) With regard to suspension. (2) With regard to maintenance. PHANTOM I. (a) When the hydraulics were introduced, we were in great trouble with harsh riding at 20 - 30 M.P.H. With Hartford's we could not avoid this and at the same time use enough load to control the car at high speeds. We proved that the hydraulics were a great improvement for this trouble and are still of the same opinion. (b) Hydraulics enabled us to control high speed wobbles. We believe that the consistency of the hydraulic has done more than anything to enable us to overcome high speed wobbles without spoiling the suspension. (c) We were never able to get Hartford's to stand up to the 60 or 70 lbs. load required in our 10,000 miles tests. The loads always varied with the weather and the bushes wore out in a few thousand miles causing terrible rattles. PHANTOM II. (a) Two features were introduced simultaneously on the Phantom II, the semi-elliptic rear spring and central oil lubrication of the spring leaves. The semi-elliptic rear spring with its longer and more flexible leaf tips appears fundamentally to have less internal friction than the old cantilever. The lubrication accentuates this difference still further. We therefore find that while we have less difficulty in getting a good low speed ride, we require a slightly different characteristic from the hydraulic to give the best road holding and car control at high speeds. Two other factors which have also altered | ||