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).
Comparison of tank projects, discussing acceleration and steering methods for tracked vehicles.
| Identifier | ExFiles\Box 144\4\ scan0185 | |
| Date | 10th December 1940 guessed | |
| 3. Mark V.{VIENNA} Weight 18 tons. Meadows engine of 250 h.p. @ 2000 r.p.m. Mark VI. Weight 18 tons. Liberty engine of 320 h.p. @ 1500 r.p.m. R.R.Project. Weight 18.5 tons. Merlin engine of 450 h.p. @ 2100 r.p.m. Track Sprocket P.C.D. of 25.8" all tanks. The figure for tank acceleration is expressed as a fraction of g and it is assumed that 70% of the engine output is available for accelerating the tank. It does not take into account any tractive resistance. From the table it can be seen that we have taken advantage of the extra horsepower and gear ratio to increase the maximum speed of our tank from 27 m.p.h. to 35 m.p.h. and to improve the acceleration or the ability to maintain a high speed on soft ground in the higher gear ratios. Steering: There is only one general method of steering track vehicles worth considering for tanks and this consists of some way of making the inner track run more slowly than the outer one. The surprising thing is the large magnitude of the forces required to do this. As a rough example it can be said that in order to persuade the tank to deviate from a straight course, it is necessary for the inner track to exert a backwards load of about three times the normal top gear tractive effort. We attach a print, Rm.{William Robotham - Chief Engineer}662 showing in diagramatic form the various methods of steering tanks and the following is a brief description of these systems. - Overleaf - | ||