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).
Notes and calculations for propeller shaft specifications based on a formula from Vauxhall and Hardy Spicers.
| Identifier | ExFiles\Box 148\4\ scan0149 | |
| Date | 8th June 1940 | |
| 1262 To Rm.{William Robotham - Chief Engineer} c. to Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. to Ev.{Ivan Evernden - coachwork} c. to Ev{Ivan Evernden - coachwork}/Tln. c. to Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} c. to Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions} Rm{William Robotham - Chief Engineer}/GB.4/JH.8.6.40. PROPELLOR SHAFTS. 30.5.39. Notes from M.Olley. The following information has been received from Vauxhall :- Hardy Spicers formula which is on the safe side is R.P.M. = 3,750,000 (D² + d²)½ / l² Where D = ext. dia. d = int. dia. l = centre to centre length in inches. the above simplifies to 5,300,000 (D-t) / l² Assuming that t = .064 (though the thickness obviously makes little difference). The Max. prop. shaft length permissible is about 50" centre to centre. Type. C.C. length. D.{John DeLooze - Company Secretary} t. Max. safe speed r.p.m. Revs. Mile. Max. safe. Road.speed. 10 HP. H 58.9" 3 .064 4500 4090 66 12 I 62.4 3¼ .064 4350 3670 71 14 J 56.75 3 .064 4830 3630 80 25 G 48.1 2¼ .064 5000 3222 93 Cont'd.{John DeLooze - Company Secretary} | ||