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).
Visit to a Sheffield firm regarding the feasibility and cost of manufacturing cast steel crankshafts.
| Identifier | ExFiles\Box 148\5\ scan0191 | |
| Date | 2nd September 1937 | |
| Crankshaft personal file To HY.{Tom Haldenby - Plant Engineer} & (Rm.{William Robotham - Chief Engineer}) From RHU/SB.{Mr Bull/Mr Bannister} c. to Hs.{Lord Ernest Hives - Chair} RHU/SB.{Mr Bull/Mr Bannister}1/MJ.2.9.37. 1260 CAST STEEL CRANKSHAFTS. On Tuesday August 31st, Mr. Topham and Mr. Elliott of Messrs. William Jessop & Co. Sheffield visited these Works with the object of discussing Cast Steel Crankshafts. This firm have had considerable experience of the production in question and as far as we can discover are the only English firm (apart from Ford) who have gone into manufacture on a production basis. The Alloy Steel used by them is much superior to the Ford Cast Iron, both as regards maximum stress and elongation. About four years ago several hundred crankshafts were produced for the Daimler Co. all of which have since run without complaint, but the practice was eventually dropped due to the cost of casting being greater than forgings. The process was developed at that time because Daimlers Crankshaft dies had broken and the only way to maintain production was by the adoption of the cast Crankshaft but the process would have been adopted permanently except for the economic standpoint. We pointed out the fact that all Ford cars have Cast Crankshafts but were told that their material is practically a plain iron which is somewhat easier to cast, furthermore their 3 bearing type of crankshaft is of a simple form and has less abrupt angles and changes in section than our seven bearing shaft. It is possible to cast the Ford Crankshaft vertically four at a time but ours would require casting singly in a horizontal mould. The space around the crank pin between the webs would have to be cast solid in order to maintain an even flow of metal which would considerably increase machining and casting weight, and furthermore the general machining allowances would not be greatly less than our present forging. It is not possible to cast or forge the large balance weights in position on Phantom III shaft due to the fact that they overhang the pins and render it impossible to grind these, hence there would be no gain on this account. The price of castings for Phantom III Crankshafts on a Production basis would be at least £10. 0. 0d. which is our present forging cost, hence there would be no advantage in changing over particularly in view of the fact that we have already paid for dies. Continued........ | ||