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).
Testing and standardisation of Bentley V rear road springs.
| Identifier | ExFiles\Box 100\1\ scan0243 | |
| Date | 6th May 1939 | |
| HH6 To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} c. By/NS.{Norman Scott} c. By/HEB.{H. Biraben} c. ROY{Sir Henry Royce}/Les.{Ivan A. Leslie} Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}3/MH.{M. Huckerby}126.39. BENTLEY V ROAD SPRINGS - REAR. We originally hoped to standardise Toledo Woodhead springs on B.V. A pair of these ran 18,500 miles on 8.B.V. without failure and similar springs have lasted 38 hours on the bump rig. We were unable to standardise them because they are bound up with interleaving which failed in the 18,500 miles. We have now obtained some interleaving which on rig tests is many times as durable as the early material, and we hope to be able to introduce Toledo Woodhead springs after a sufficient mileage has been done on this new interleaving. We had to revert to Firth springs for production. A pair of 8 leaf springs were fitted to 8.B.V. and these failed after 27,000 miles. On the bump rig the same type of spring failed in 9 hours. This life is inadequate. We then obtained the spring FB.4368. This is made by modifying the 8 leaf spring and adding a thin helper leaf. Two springs were tested. The earliest failures took place after 16 hours (2nd. and 8th. leaves) but the main leaf did not fail until 22 hours. As the appearance of this spring is unusual we obtained a pair of 9 leaf springs, all leaves being equal in thickness. The first leaf to fail was the main leaf after 14-2/3rds. hours. We therefore recommend that the spring FB.4368 should remain on production until we can change to the Woodhead springs. A drawing has been prepared incorporating the larger oil grooves necessary to reduce local high stresses. No more than 100 sets should be ordered without determining the position of the Woodhead spring as regards standardisation. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||