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).
Chassis road spring poundage, specifications, and ordering procedures for various models.
| Identifier | ExFiles\Box 154a\4\ scan0005 | |
| Date | 20th November 1936 | |
| 1306 To Hs.{Lord Ernest Hives - Chair} from Rm{William Robotham - Chief Engineer}/Les.{Ivan A. Leslie} c.c. to RHC.{R. H. Coverley - Production Engineer} Rm{William Robotham - Chief Engineer}/Les.18/AP.20.11.36. CHASSIS ROAD SPRINGS. Re. No.8/KW.18.11.36. The chassis held up for road springs is 3-AX-87. This chassis has been re-allotted and is now going to Kenya with a very heavy body. The rear springs now fitted are 1350 lbs. and the spring poundage called for this car is 1550 lbs. It is imperative that these springs are changed. Re spring poundage graduations. It appears that these could be graded in 100 lbs. The introduction of a new piece number for every 50 lbs. started with Phantom II. The 30 HP. rear springs are still in 100 lbs. stages. The degree of accuracy of poundage is increased by lower rating springs. For Wraith we are hoping to use less accurately produced rear springs. This will result in a wider limit for poundages. If the springs are ordered in 100 lbs. stages selective assembly should give adequate variation. Actually, we see no reason why separate piece numbers should be given to each poundage. We think Roy.{Sir Henry Royce} should order the most suitable poundage spring to the drawing number. We suggest that the erection card should give the ideal spring poundage for the chassis, so that the most suitable springs available can be selected. A limit of +- 50 lbs. could be given for selection making a possible variation of 100 lbs. The ideal spring poundage for every chassis would go to Roy.{Sir Henry Royce}, to enable correct ordering for future series. This, with suitable warning from the Design or Experimental Department of any likely change in poundage, should enable Roy.{Sir Henry Royce} to order springs with the minimum scrap at the end of a series. Recently, in view of the lack of driving visibility of Phantom III. Roy.{Sir Henry Royce} and By.{R.W. Bailey - Chief Engineer} were warned of a liable increase in rear spring poundage. This has accentuated the present shortage of higher poundage springs. continued. | ||