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).
Impossibility of an armoured car carrying a proposed weight without a new axle and the challenges of sand testing.
| Identifier | Morton\M21\ img073 | |
| Date | 29th August 1921 | |
| To BJ. from DA.{Bernard Day - Chassis Design} RE ARMOURED CARS. With reference to your BJ24/H25/8/21, it is impossible for the present car without the new axle, to carry the proposed weight of 4 tons 6 cwts. up some of the hills, and to go through the sand test, but it could be made to go over the ground for our own satisfaction with a proportionately reduced load, which we could give the test department if they require it This would enable us to see whether the cooling was at fault apart from the gear ratio, and would also give us an idea of the general practicability of the tests. The only doubtful point is the sand test, as it is practically impossible to calculate the effect of this resistance, and it may be desirable to get some experience on this before we went forward with other tests. We know that for instance, a 20 H.P. 30 cwt. Albion chassis was able to do the figures of eight with ease with a sufficiently low gear ratio. The resistance of the sand might rise considerably with an increase of speed. DA.{Bernard Day - Chassis Design} | ||