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).
Crankshaft failure at the flywheel flange and analysis of related failures.
| Identifier | ExFiles\Box 85\5\ scan0126 | |
| Date | 19th February 1937 | |
| B 217. To Rm.{William Robotham - Chief Engineer} from HPS{Horace Percy Smith - Experimental Factory Mgr}/RH.{R. Hollingworth} c.c. to HPS.{Horace Percy Smith - Experimental Factory Mgr} c.c. to Hm{Capt. W. Hallam - Head Repairs}/Swdl.{Len H. Swindell} HPS{Horace Percy Smith - Experimental Factory Mgr}/RH.{R. Hollingworth}1/CB.19.2.37. UNIT B.19. CRANKSHAFT FAILURE. Crankshaft EB.1083 modified to EB.2687 4004.A. R.R.14 - VCM. On dismantling the above unit the crankshaft was found to be broken at the flywheel flange. Herewith drawing Ex.I.129, showing the nature and extent of the breakage. The .025" radius on the flange face at which the breakage has occurred, is not called for on the drawing EB.2687, its presence being due to the fact that this is a modified EB.1083 crankshaft. This crankshaft has completed a total of 299 1/2 hours running, including 149 hours at full throttle, 10 hours 50 minutes at 1/4 load and 3,300 miles in chassis 6.B.IV. Since December 17th 1936, this is the third crankshaft to be reported broken or cracked at the flywheel flange, which is obviously a weak point, and it would seem that after about 300 hours test bed work, a crankshaft has concluded its useful life and any extension of this running time is likely to incur breakage due to fatigue. B.17 crankshaft, reported 17.12.36, failed after 119 hours test bed running and 21,960 miles road work; B.9 crankshaft reported 18.2.37, failed after 410 3/4 hours, both being EB.1083 crankshafts modified to Ex.18203. R.{Sir Henry Royce} Hollingworth. | ||