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).
Laboratory report on a broken Condor crankshaft (CX6) discussing issues with heat treatment and material properties.
| Identifier | ExFiles\Box 76\3\ scan0106 | |
| Date | 16th April 1919 | |
| R.R. 285 A (100 T) (S.F. 575. 16-4-19. C. 2354. [strikethrough]BY[/strikethrough] [strikethrough]c to P[/strikethrough] [strikethrough]c to Rn{Mr Robinson}[/strikethrough] c to EH. H11/EB91019. Laboratory. RE BROKEN CONDOR CRANKSHAFT CX{Major Len W. Cox - Advertising Manager}6. The test figures given in your note BY6/F61019, are exceptionally good, so that it appears probable that the steel tested was not in this particular case representative of the crank itself, even though the test piece was connected to the shaft during heat treatment, it may be that the different forging it received and also its different section may have produced different mechanical results on heat treatment. The cranks, of which CX{Major Len W. Cox - Advertising Manager}6 is one, were as you know, hand forged, and of very large sizes as compared with the final machined crank shaft, and it is quite likely that the heating for quenching was not sufficient to correct the interior metal in the same manner as it did the test piece end. In any case prolonged normalising should have been done before heat treatment; the micro structure and fracture indicate that this has been omitted. A further crank shaft CX{Major Len W. Cox - Advertising Manager}2(?) which had been scrapped for other reasons has been examined at both ends and shows a similar faulty condition. Izod and Tensile bars are being taken from this crank. The test results will be reported when completed. lrdh | ||