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).
Performance issues and proposed alterations for armoured cars destined for India.
| Identifier | Morton\M21\ img075 | |
| Date | 27th June 1921 | |
| To R.{Sir Henry Royce} from DA.{Bernard Day - Chassis Design} Copy to BY.{R.W. Bailey - Chief Engineer} Mr. Maddocks. RE ARMOURED CARS. (INDIA) I went to see Col. Robinson at the India Office and Col. Hutchinson at the War Office on Thursday last. When the armoured cars for both the India and War Office were ordered they were ordered on the merits of the previous R.R. cars they had had, and no particular performance was specified, but now that they have got the cars, they appears to be subjecting them to tests which should not have been contemplated. They have, for instance, tried to take two of the chassis that have been delivered for the India Office up a gradient of 1 in 4, carrying 9688 lbs. The Experimental Dept. say that the present car will stall on a gradient of 1 in 4 with a load of 7840 lbs. Against this has to be considered that the back axle ratio has been altered from 16:52 to 14:52 in the case of these armoured cars, but on the other hand the wheel diameter has been increased from 34" to 38". The total effect is to produce a gear ratio on these cars about equal to, for instance, the cars which went to the Alpine Austrian Trials. We have told them that under the circumstances it is certain that the cars will not take this weight up a gradient of 1 in 4, and they have agreed to this. They now say, however, that in order to justify the expenditure on these cars and the expenditure on future armoured cars, it will be necessary that they should carry this load up a gradient of 1 in 4 at the sea level, and they would like us to suggest what alterations should be made in order to do this. I am about to look into the question of altering the ratios in the gear box by dropping the speed of the second motion (Contd.) | ||