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).
Page of handwritten calculations determining the gradient climbing ability for a Spectre model.
| Identifier | ExFiles\Box 94\1\ scan0149 | |
| Date | 1st July 1935 | |
| SpectreCodename for Phantom III x32B Gearbox Relay 1-7-35. Grad. Climbed on 2nd spd. Axle 4.25:1 2nd .503 Overall 8.44 Tyres effec rad 15" Wt complete car 49 cwt. " 6 persons & 2cwt. luggage 9.5 _____ 58.5 6550 lbs Force available at Tyres = BMEP x qc x Gear Ratio x Effy Transmission / Tyre. Dyredia x 1.03 = 110 x 73.60 x 8.5 x .85 / 30 x 1.03 = 1900 lbs Percentage of wt. 1900 / 6550 = 29.0 % Say trac. res. 80 lbs/ton * 80/2240 = 3.6% _____ Balance 25.4% _____ = grad. 1 in 4 * on high side according to IAE data sheet no. 14. Are gradients given this way -> on Ordnance Survey maps? [Diagram of a right-angled triangle with the hypotenuse labelled 'x' and the vertical side labelled '1.0'] DJM | ||