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-benefit analysis of sourcing propeller shafts from Hardy Spicers versus in-house production.
| Identifier | ExFiles\Box 87\3\ scan0071 | |
| Date | 24th November 1936 | |
| C O P Y. Hs.{Lord Ernest Hives - Chair} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to RHC.{R. H. Coverley - Production Engineer} Rm{William Robotham - Chief Engineer}/Gryll/R.24.11.36. Dictated 18.11.36. PROPELLER SHAFTS. Our present propeller shafts cost including over-heads £9/10/- per complete assembly. The estimated cost reduction for Wraith is £4/16/-. Neither of these figures includes the time required to balance the shafts. We found on two 10,000 mile tests that a shaft bought from Hardy Spicers at about £2/10/- was entirely satisfactory on the Bentley as regards reliability and functioning. The objections to it were, firstly, that it was not balanced, and, secondly, that no provision was avilable for balancing. If we were to buy shafts from Spicers, then fit a Rolls-Royce made coupling yoke having an integral balancing flange and finally touch up the appearance, we should have obtained satisfactory assemblies at about £3/5/2. As this again raises the question of the advisability of using proprietary articles for a saving of £1/9/- per car, we should be glad of your views on this particular part. We do not think we shall ever produce shafts in this factory at the Spicer figure owing to the enormous numbers they manufacture. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} P.S. It should not be thought that Hardy Spicers use cheap material, as we have found that the spline sliding joint is made of at least 75 ton material. | ||