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).
The testing and comparison of different engine springs made from Swedish wire and Chrome-vanadium.
| Identifier | ExFiles\Box 158\4\ scan0132 | |
| Date | 5th March 1937 | |
| -2- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}8/R.5.3.37. (3) This Rm.{William Robotham - Chief Engineer}260 drawing was copied by the D.O. to EB.3256, and springs coiled here in Swedish wire bought from the Tempered Spring Co. On the rig, as Hy.{Tom Haldenby - Plant Engineer} states, two of these springs failed in 4 hours. Similar springs were tried out on the Test Bed and though better for surge than standard EB.175, were not so good as the Rm.{William Robotham - Chief Engineer}260 springs. Upon comparing them, the finishing of the end coils and the close coiling effect was slightly different, and the Spring Dept. are now producing to a model Rm.{William Robotham - Chief Engineer}260, which we hope will be as good in their performance. (4) With regard to our standard Chrome-vanadium springs, EB.175, we are not so free from troubles as suggested, and recently broke two in an 8 hours endurance run. Likewise we have also broken several similar springs in Swedish wire made by the Tempered Spring Co. It will be seen from the foregoing results that there is no claim of the "Swedish Wire" being so reliable as "Chrome-vanadium", but simply that cutting out the surge by close coiling does overcome failure. The same advantage would be obtained whatever the material, and the only reason we have applied it to Swedish Wire is in the hope that the ultimate result will be as follows:- (a) Cheaper springs. (b) Quiet operation due to no surge. (c) Reliability on a par with existing springs. Rm{William Robotham - Chief Engineer}/Swindall. | ||