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).
Curve graph showing horsepower required to drive a 40/50 HP car up a 1 in 12 gradient.
| Identifier | WestWitteringFiles\L\July1924-September1924\ Scan30 | |
| Date | 1st September 1924 guessed | |
| SHEET 2 CURVE SHOWING H.P. REQ TO DRIVE 40/50 H.P. CAR. UP A 1 IN 12 GRADIENT WT. OF CAR ASSUMED TO BE 2 TON THE CURVE SHOWING POWER REQUIRED IS CALCULATED FROM FIGURES OBTAINED FOR THE TRACTIVE RESISTANCE OF A 40/50 HP CAR. THE PERCENTAGE OF FULL LOAD UNDER WHICH THE ENG. IS WORKING AT DIFFERENT SPEEDS & ON VARIOUS GEAR RATIOS CAN BE OBTAINED EXAMPLE:- SPEED 20 M.P.H. 3RD GEAR. % OF FULL LOAD ON ENG. = EQ / EC = 59% HORSE POWER H.P. AT WHEELS 2ND GEAR H.P. AT WHEELS 3RD GEAR HP. REQUIRED TO DRIVE CAR UP A GRADIENT OF 1/12. H.P. AT WHEELS TOP GEAR MILES/HOUR. ENG. R.P.M TOP GEAR ENG. R.P.M 3RD. GEAR ENG. R.P.M. 2ND GEAR acfs | ||