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).
Comparison of vehicle frame construction methods, contrasting riveting with spot and torch welding.
| Identifier | ExFiles\Box 126\4\ scan0092 | |
| Date | 26th September 1935 guessed | |
| (4) at the front end does to some extent handicap lateral rigidity, and a frame with the cruciform member forward and triangulations such as we are fitting in the latter half of the SpectreCodename for Phantom III frame between the rear gearbox crossmember and the crossmember opposite the front ends of the rear springs should bring the lateral rigidity up to a still higher value than the Daimler effort. At the same time this enables us to fit bodywork with rear foot wells, which is impossible on the Daimler. The height of the Daimler frame from the ground is no lower than our Wraith will be. Finally the method of assembly of the Daimler frame is by a medium number of large rivets and a considerable amount of torch welding. There is no spot welding evident. I mention this point because I have information that the Leyland Co. have recently given up spot welding as they found it came apart in use, and they have gone to considerable expense in replacing failed spot welded structures with rivetted structures having no welding of any sort. In the case of the SpectreCodename for Phantom III except the first chassis built, which was of all rivetted and bolted construction, we buy the boxed side channels spot welded, from the makers, and we use a certain amount of spot welding in the assembly of the cruciform crossmember. It is true that we tore some spot welding apart on the front end of the frame by overloading it with a chain, but since then the frame has been stiffened, and as regards bumper rig tests and the chassis which has done 20,000 miles in France, we have had no trouble. Our frames have been spot welded with the Sciaky machine, which is also used extensively by the Citroen Co. It is possible that the Leyland spot welding was not done in the same way, but I am having enquiries made with regard to this point. It is also possible that the Leyland people expected too much of a spot welded joint and used it for other applications than pure sheer to which we limit its use. We do not favour torch welding very much as it is much more dependent on the human factor and inspection after welding does not reveal internal faults. I am, therefore, watching the position closely regarding this question of means of holding the frame together so as to avoid as far as | ||