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).
Material change for the Phantom III exhaust system from Staybrite to aluminised steel, including cost analysis and a proposed design modification.
| Identifier | ExFiles\Box 93\1\ scan0101 | |
| Date | 22th November 1937 | |
| [Handwritten] To By and Rm.{William Robotham - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} c. LA.{L. A. Archer} Wymans 523 I don't quite understand this but it would appear that £2/5/6 is all the saving they are going to get. Do you agree. Rm{William Robotham - Chief Engineer} [Typed] ALUMINISED EXHAUST SYSTEM. PHANTOM III. It has not been found possible to produce front downtake pipes for Phantom III. to a sufficient degree of accuracy for them to be interchangeable, and due to close clearances in the chassis it is essential to fit every pipe individually in the Erecting Bay. It will therefore not be possible to aluminise downtakes because the chassis would be standing incomplete for two weeks whilst the pipes were away for treatment. The total material saving by producing the downtakes, intermediate pipe, and front expansion box in aluminised Mild Steel as compared with the present Staybrite is £5.1.0d. per chassis, but if the front downtakes remained in Staybrite this saving would drop to £2.11.0d. We understand, however, that development is proceeding with nickel deposited Mild Steel downtake pipes, and we should like to know whether there is a likelihood of these being released to production before March, 1938, in which case it would be possible to incorporate them in the 2nd 100 chassis in 'D' series. The first 100 sets of Staybrite exhaust system material are already in stock, hence in any case it would not be possible to fit the aluminised system until the 101st chassis in 'D' series. The design of the aluminised intermediate pipe, differs from present standard in being separated from the rear silencer by a flanged Joint, but it is considered that the Welded Joint could be retained if the aluminising ceased about 2,000 from the Weld, as shown in the sketch. The above figures are based on the assumption that this will be done, but should the flanged Joint be retained the chassis saving will be reduced by about 5/6d in each case or to £4.15.6d. for the fully aluminised system, and £2.5.6d. if the downtakes remained in Staybrite. [Diagram Text] INTER PIPE REAR SILENCER PRESENT DESIGN OF ALUMINISED SYSTEM WITH 4 BOLT FLANGE EXTENT OF ALUMINISING PROPOSED MODIFICATION WITH WELDED JOINT [Typed] RHC{R. H. Coverley - Production Engineer}/S.Bannister. | ||