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).
Comparing the performance of Derihon, Houdaillle, and Berkshire hydraulic shock absorbers.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan310 | |
| Date | 12th June 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.I. ORIGINAL REF: Hs{Lord Ernest Hives - Chair}/RM{William Robotham - Chief Engineer}/A/1026.9.25. C EXPERIMENTAL REPORT. Expl. No. To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/RM.{William Robotham - Chief Engineer} c. to CJ. RJ. c. to RG.{Mr Rowledge} R.{Sir Henry Royce} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} HYDRAULIC SHOCK ABSORBERS X457 X8520 We have tested three types of hydraulic shock absorbers - these are - Derihon. Houdaillle. Berkshire. The tests consisted of adjusting the shock absorbers to three-quarters their maximum loading and running them at a speed equivalent to 30 m.p.h. on a chassis on the bump rig. We also tested the Berkshire shock absorbers for 400 miles on ordinary main roads. We found that in every case, oil leaked badly from the glands after a few minutes running. As soon as the shock absorbers became hot, their efficiency decreased enormously. The oil leaked on the Derihon so much that after 2 hrs. running one shock absorber was entirely out of action, the other was very feeble. The Houdaillle were perhaps the best of the three types tested but they leaked oil copiously and one lost 90% of its efficiency after 1 hrs. running. The Berkshires were covered with oil which exuded from the gland after a 400 miles road test. On the bumping rig however they did not lose so much oil as the Derihon, and when allowed to cool down after the test, recovered some of their original efficiency. contd :- | ||