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).
Cost and feasibility analysis comparing different welded axle designs, specifically a banjo type versus a butt-welded tube design.
| Identifier | ExFiles\Box 114\1\ scan0052 | |
| Date | 24th September 1936 | |
| (sheet 3) Type. Cost. Remarks. (2) Banjo (in two halves welded). £3.15.0 As modified for welded banjo. This is comparable with the P.III design in which the centre casing has been left out. (3) Phantom III design with butt welded axle tubes. £5.5.0. To make this cost comparable with the banjo the same parts have been included as in item (1). The costs of the third item have been based on the figure given by Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} for buying axle tubes butt welded, as shown on the blueprint attached to Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}15/KW.24.9.36, and no addition has been made for a modification to the design which would be obviously necessary to get the spring seats and brake carrier in position. Actually we understand that the only people who have the necessary equipment in this Country for making such tubes are Ford's at Dagenham. Rubery Owen's are unable to make a successful weld in the medium carbon steel, and also the weld on the larger end of the tube would be beyond the capacity of their machines. We question the advisability of using welding in this way carrying direct stresses on a Rolls-Royce car. Undoubtedly there are thousands of cars in existence in which this is being done with satisfactory results, notably the Ford rear axles, and all cars employing Dubonnet front suspension, but these cars are of the medium performance type, and do not have to withstand the high speeds, and carry the heavier coachwork to which we are accustomed. To put the matter in the simplest possible light it is equivalent to sawing the axle casing through into two parts and then welding it up again. | ||