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 Myrth frame tests, detailing torsional stiffness results and recommendations for stiffening improvements.
| Identifier | ExFiles\Box 110\2\ scan0060 | |
| Date | 15th December 1943 | |
| Chassis To: Rm.{William Robotham - Chief Engineer} from FJH{Fred J. Hardy - Chief Dev. Engineer}/GB. c. to Ev.{Ivan Evernden - coachwork} c. to Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} c. to Vym. c. to Vym/Cr.{Mr Cra???ster / Mr Chichester} File 727 FJH{Fred J. Hardy - Chief Dev. Engineer}/GB.3/IBL. 15.12.43. Myrth Frame Tests. The Myrth frame to EP.{G. Eric Platford - Chief Quality Engineer}2259 was originally tested for torsional stiffness in Dec.'41 and the rate was 394 lb.ft./deg. from wheel to wheel. It was obvious from the test results (see attached graph) that the frame required stiffening at the front. Accordingly the front cross member which was open was boxed in to IL.1127. (See Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames}10/KC. 8.1.42.) The second test just completed showed that this change had raised the stiffness by 144 lb.ft/deg. to 538 lb.ft/deg. from wheel to wheel for a weight increase of only 1/4 lb. The last 40" of the frame could now do with some stiffening. Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} has agreed to look into the possibilities of boxing in the rearmost member. The spot welding of some of the body mounting brackets to the frame is a very poor quality. In addition design here leaves much to be desired, because the spot welds are not close to the supporting flanges on either the brackets or side members. Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} is having suitable modifications made here. In the meantime we would like the frame to be tack welded where the spots have not taken and also at several points near the rear ends of the side member front reinforcements. FJH{Fred J. Hardy - Chief Dev. Engineer}/GB. | ||