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).
Subframe and chassis interchangeability for S.S. bodies and guidance for coachbuilders.
| Identifier | ExFiles\Box 15\4\ Scan044 | |
| Date | 29th April 1929 | |
| Ha/AJL. from DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} c. to Wor.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} RE. BODIES FOR S.S. We thank you for your Hs{Lord Ernest Hives - Chair}/AJL1/LG22.4.29. It is essential that any subframe shall fit any chassis. To make this possible we have provided ample adjustments at the subframe fixings. The difficulty chiefly occurs in the variations in the rise of the upsweep of the rear of the frame which appear to be due to these frames being made by bending frames made for EAC.7. We believe that this difficulty will disappear on production, especially if the rear bracket is fixed as we suggested in our memo. to RHC{R. H. Coverley - Production Engineer}, not at a distance relative to the level top of the frame, but relative to the top of the upsweep. The difficulty cannot be unsurmountable, for the Daimler Co. have provided interchangeable subframes for years. Assuming that it is agreed that we must, and can, make subframes and chassis interchangeable at Derby, we have next to ensure that they (subframes) do not get damaged in transit. The present system of crating seems adequate. To prevent the coachbuilder damaging the frame during the building of the body, we think the extra crossmembers which you have introduced are good. We agree with your suggestion of a dummy chassis for each coachbuilder, in theory, and are sorry that it is impractical. There are 92 coachbuilders in this country alone, besides our coachbuilders in France, Spain, Portugal, Germany, Italy, India, Australia and South Africa. We cannot give them all a dummy chassis or a jig. We shall give the coachbuilder ample information to enable him to avoid fouls. If he does not make his body correctly to our prints, it is he that will suffer, for he will have to mount the body. All we have to do is to be sure that - (1) The subframe is correct. (2) The chassis is correct. (3) The subframe has not been damaged in transit. (4) The subframe has not be distorted in the building of the body (5) The coachbuilders' prints are correct. In the case od Barkers, Hoopers, Windovers, Thrupps etc. where there is a large number of our bodies being made, we shall indicate to the coachbuilder how we can construct a suitable jig. This will appear in our book on the subject of 'Body Subframes'. contd :- | ||