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).
Confidential memorandum discussing the design progress and challenges of the 'Myth' car project, specifically regarding the frame and body structure.
| Identifier | ExFiles\Box 109\2\ scan0071 | |
| Date | 23th October 1940 | |
| 1030 To Rm.{William Robotham - Chief Engineer} CONFIDENTIAL. Ev.{Ivan Evernden - coachwork}1/JH.23.10.40. 704 re Myth. The first project for the Myth body and frame is dated September 2nd. 1939 and is PD.500. This was followed almost immediately by a finalised quarter scale layout of the frame and body attachment PL.20. on October 11th. 1939. The scheme consisted of an all steel body with a wheel-borrow which faded out towards the rear of the car. At this point work on the Myth frame and suspension was held up because it was decided that priority had to be given to the completion of the Senior Range and in particular Ripplet and Rippletto both of which cars we intended to build an experimental sample as soon as possible. On May 21st. 1940, the Coachwork Dept. at the Clan took over the design of the Myth body and frame, from the stage at which we left it on PL.20. Although quite a lot of progress has been made towards the settlement of the actual lines, shape and interior capacity of the body, we have got very little or no way with projecting the base of the body either as a monocoque or a frame with a body mounted on it. In fact we seem to be at the PL.20 stage or not quite so far. We share your anxiety to complete the designs for the immediate Post War Production Myth and the units for this car are nearly finished. We cannot proceed any further until the frame and body base liason is settled. We understand that we now no longer wish to build a Myth with an orthodox frame and body mounted with rubber on Cantilever brackets, because the flexibility of the brackets fixes the upper limit of the rigidity of the connection at a too low level. We understand that you require some form of frame cum body sill unity with the possibility of various degrees of rigidity of coupling between the two units. A survey of current practice of small monocoque cars we believe has provided us (Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions} Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} & Ev{Ivan Evernden - coachwork}) with a solution. The mounting can have all degrees of flexibility or insulation ranging from rubber pads to a solid junction of continuous welding. In the latter case the body becomes a monocoque with sill structure almost similar to that already designed by Rm{William Robotham - Chief Engineer}/EAG. We would like to show you the idea and then, please may we go ahead with a quarter scale project of the frame and body structure. | ||