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).
Proposal for a joint project with Leyland to improve the Mark VI tank's engine, transmission, and armament.
| Identifier | ExFiles\Box 144\4\ scan0156 | |
| Date | 10th November 1940 | |
| - 3 - Cont'd.{John DeLooze - Company Secretary} Rm.{William Robotham - Chief Engineer}5/ML.10.11.40. 3. PROPOSED ROLLS ROYCE - LEYLAND PROJECT. To make the Mark VI. tank cover these dual requirements, it is necessary for it to have a better power weight ratio than at present. The Liberty engine now being used has the same displacement as a Merlin and gives 340 h.p. It weighs about 2,000 lbs. It was designed in 1918. It's valve gear is exposed, which is bad for the dust conditions in a tank. If replaced by a naturally aspirated Merlin we should expect to get between 450 and 500 h.p. Such an engine would provide a power weight ratio which would not need more than a 4-speed gearbox and would also enable the steering to be simplified, since the type of steering on a tank is dictated by the surplus power available in any gear. It is proposed that Messrs Leyland and Rolls Royce prepare designs for an engine and transmission unit, based on the Merlin design but with cast-iron substituted for aluminium. The first step is to run a naturally aspirated Kestrel engine on Pool petrol and establish a power curve for an aero engine run under these conditions. Messrs Leyland's would make the prototype, which would then be tested in a Mark VI. tank. This work having been completed, the next step would be to simplify any of the other tank pieces which are unnecessarily difficult, as far as we can, and also to strengthen the track up to take care of the increased armour plate necessary to give this tank it's dual role. It is not inconceivable that in 12 months time a prototype might be running. If an existing Merlin engine was available, a lash-up test could be carried out in a much shorter space of time. The fact that all the Merlin pieces are at present in production would be a great help in getting the unit made if and when it was decided to introduce it owing to all jig and tool design and manufacturing technique being available. If the change came, Leyland's would, we expect, manufacture this engine instead of the Meadows. 4. ARMAMENT. There is definite scope for improving the armament on this tank. On the other hand, the turret appears to be about the only item that is thoroughly standardised, and therefore it would be necessary to make some big improvement to justify the upset that would be occasioned in production. Nevertheless, if our Armament Division have capacity available, they might with advantage investigate the turret. - Continued - | ||