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).
Vehicle climbing performance based on weight, gradient, and wheel size.
| Identifier | Morton\M21\ img069 | |
| Date | 1st July 1921 guessed | |
| Col.Robinson. -3- DA{Bernard Day - Chassis Design}7/G28621 Contd. The maximum weight up a gradient of 5.9 (38" wheels) - 9220 lbs. The maximum weight up a gradient of 5.9 (40" wheels) - 8750 lbs. The actual weight taken up 1 in 5.9 was, I understand 8904 lbs. with 38" wheels. On the same lines this figure represents a M.E.P. of 71.2 lbs. per sq. inch., shewing that a little better performance could have been made with some adjustment of the weight, but the final figures given, namely, 7868 with 38" wheels and 7161 with 40" wheels, climbing a gradient of 1 in 4 are impossible, as they represent M.E.P. 89.8 lbs. per sq.in. and 85.5 lbs. per sq.in. respectively. Possibly there is some discrepancy either in the actual gradient or in the weights, but of course a considerably increased weight could be carried up a gradient of 1 in 4 for a short while by making use of the stored up energy in the car. If high compression pistons are used the climbing capabilities of the car are appreciably increased. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||