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).
Analysis of scuttle and bonnet vibration issues, arguing against total isolation in favour of semi-isolation.
| Identifier | ExFiles\Box 14\4\ Scan038 | |
| Date | 2nd March 1928 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Hm.{Capt. W. Hallam - Head Repairs} CWB. c. to Sg.{Arthur F. Sidgreaves - MD} C. c. to Ps. Pt. X7500 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LGL2.3.28. SEMI ISOLATION. (4613 We are strongly opposed to total isolation. In our experience it produces scuttle jellying and bonnet rattles. The most recent example of this was on 10-G3. The scuttle moved about so much that every pipe between the instrument board and the dash was broken except the oil gauge, thus throwing out of action the screen wiper, distance petrol gauge etc. The scuttle was semi-isolated and the car ran 10,000 miles without further trouble. Trials car 7-LC was another example and gave a most unfavourable impression when we took it over to France. The case of 15-EX is rather different because the WW. scuttle damper prevented jellying. However the bonnet rattles on this car were most objectionable, even when the column was rigidly supported by stays, until we adopted semi-isolation. As we see it, the scuttle rigid longitudinally but flabby transversally, the dash immensely strong transversally but weak fore and aft. The scuttle damper deals with the body movement reasonably effectively, but the dash still deflects being pulled about by the radiator causing irritating bonnet and control rattles. The Whole arrangement does not seem so satisfactory contd :- | ||