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).
Development, costs, and implementation of a new gearbox for the Bentley 111.
| Identifier | ExFiles\Box 99\4\ scan0155 | |
| Date | 4th November 1938 | |
| RHC{R. H. Coverley - Production Engineer}/MSC c. RHC{R. H. Coverley - Production Engineer} c. Rm.{William Robotham - Chief Engineer} 428 BENTLEY 111. RE: GEAR BOX. I have given this matter the most careful consideration, and whilst we are admittedly behind the clock, there are reasons which are so strong as to almost amount to necessities, why we must not at this point abandon the effort to bring in the new box with Bentley 111. In the first place, since the engine and rear axle are to current designs and details, more time can be allowed for the gearbox than if the engine and axle were also new and demanded new jigs and machining considerations. We need economies, both in regard to production cost and weight reduction on Bentley 111, and the new box offers a reduction in production cost of at least 15% and a weight reduction of 8 lbs. It is not necessary at this stage to use the new box for Wraith, it is not suitable until we introduce the Wraith replacement with 30% increased power when the low gear would only be an emergency gear, and as it would not be used for ordinary work it would not be a source of annoyance. The new box is doing well in France, no gears are working out, the box is admittedly quiet on all but first and reverse, the synchro mesh is light in operation, and any of the points so far mentioned can be overcome. The reasons of economy and weight saving, which were considered as strong enough to demand a new design still operate, and as I can release the box at once for tool consideration, we can in my opinion defer a decision for three months from date without jeopardising our programme. Assuming the tools &c. to cost between £9000 and £10,000, the first cost would be written off over about 1200 chassis, and this again means we should make a determined effort to bring in the new box. My decision is therefore, we must if necessity arises even face delay rather than abandon our effort, which I am assured will, even if somewhat delayed, be successful. BY.{R.W. Bailey - Chief Engineer} | ||