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 'Myth' frame design, comparing conventional and monocoque construction options.
| Identifier | ExFiles\Box 113\5\ scan0146 | |
| Date | 29th October 1940 | |
| EV.{Ivan Evernden - coachwork} from Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/EAG. Frames 1010 Rm.{William Robotham - Chief Engineer}3/ML.29.10.40. re MYTH FRAME DESIGN. We have been giving considerable thought to the way in which we should tackle the Myth frame. The three alternatives are :- 1. Conventional frame with outrigger supports carrying rubber insulating pads. 2. A monocoque construction on the lines of the Austin, with provision for inserting rubber pads of restricted dimensions if that should be found necessary to produce the requisite degree of silence. 3. Full monocoque with no provision for noise insulation. It was originally decided to adopt Scheme 1. We queried the distance between the frame and the body bottom side and the resultant lack of rigidity due to the extended outrigger supports and, in consequence, Scheme 2. was put forward as an alternative. Protracted consideration of Scheme 2. indicates that it is going to be exceedingly difficult as a production proposition. If the rubber insulation is not correctly assembled, we shall get neither rigidity nor noise insulation. As far as we can ascertain, the difference in weight between the separate frame scheme and the combined frame and body bottom side, cannot be more than 50 lbs. If we get a quiet car for 50 lbs. extra weight, we shall have got a bargain, so far as the Rolls Royce type of clientele is concerned. The full monocoque insulated body is out of the question for the moment. Under the circumstances, we should Rm{William Robotham - Chief Engineer}/EAG to design his body bottom side first for the frame as it has at present been drawn, making it as light as he can, in view of the fact that it will receive some support. P.T.O. - Continued - | ||