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 weight reduction for the Bentley by using Hardy Spicer propeller shafts.
| Identifier | ExFiles\Box 148\5\ scan0103 | |
| Date | 13th December 1935 | |
| To Wor.{Arthur Wormald - General Works Manager} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to E.{Mr Elliott - Chief Engineer} x200 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}7/KW.13.12.35. Cost Reduction on the Bentley. We have for some time past been experimenting with Hardy Spicer propellor shafts. We believe that E.{Mr Elliott - Chief Engineer} was the first to suggest obtaining these shafts from the Hardy Spicer Company. Our original interest in this shaft was to save weight. The first one submitted to us, however, was no lighter than the existing standard shaft. In spite of this, we ran it 12,500 miles on 5-B-IV car. Hancock's remarks at the completion of the test were - "Hardy Spicer Propellor Shaft". "The propellor shaft universal joints show no slackness, no wear can be detected. The joints are sealed and no lubrication necessary. The splines on the sliding joints do not show excessive wear. There is a sign of hard places where movement has taken place, not sufficient to cause any trouble." From these remarks it will be seen that the propellor shaft has proved itself to be completely reliable. Since this test we got the manufacturers to reduce the weight by 4 lbs., and this lightened shaft is about to run another 15,000 miles on 6-B-IV. If we go yet another step and use their standard flanged yoke, we save a few shillings and 2½ to 2¾ lbs. weight in addition. It appears to us that we should at once take advantage of the tests that have been carried out to effect a considerable reduction in cost on this item, either by buying the propellor shaft from Hardy Spicers, or manufacturing it in our own factory to their drawings. The Hardy Spicer shaft as it is costs something less than £3; our own shaft, without the inclusion of overheads, costs £6. 14. 6d. I think possibly all would agree that we should want a somewhat better external finish than we have got on the shaft we have tested. | ||