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).
Phone message compilation discussing the failure of aero connecting rods and potential solutions.
| Identifier | ExFiles\Box 179b\1\ img313 | |
| Date | 1st February 1933 | |
| S. FROM R.{Sir Henry Royce} ORIGINAL COMPILATION OF 'PHONE MESSAGE. C. to WOR.{Arthur Wormald - General Works Manager} EC. HS.{Lord Ernest Hives - Chair} Er. BY.{R.W. Bailey - Chief Engineer} re. AERO CONNECTING RODS. I have telephoned to WOM., RG.{Mr Rowledge}, HS.{Lord Ernest Hives - Chair}, E.{Mr Elliott - Chief Engineer}, BY.{R.W. Bailey - Chief Engineer}, as follows: (1) At the moment my information is that we have not yet been able to decide the cause of the failure. (2) It is however almost certainly the failure of the bearing, and not simply mechanical stresses. (3) So that something goes wrong with the white metal, and evidence rather favours that this is not sudden, but comes about somewhat slowly. (4) My impression is that owing to the heavy loads of the high maximum pressures one of two things occur - (a) the white metal breaks up, or (b) the lubrication is squeezed out, and not replaced in time for the next high pressure. (5) (a) can best be improved by the lead bronze; (b) is easier and probably can be improved by the oil passages and grooves. (6) The car engines have always been instructed from AW. with y holes into the crankshaft at the main bearing, and side grooves extending 60° each side in the main bearings (no grooves where maximum load falls.) E.{Mr Elliott - Chief Engineer} will confirm this. Recent aero work has been arranged at Derby. I am not sure if our car engine scheme has always been carried out, even on car work, and recent reports shew certainly not in aero. (7) Mr. Hall, working on some tests I believe I suggested to BY.{R.W. Bailey - Chief Engineer}, has just sent in some results that shew both lead bronze and white metal failing to carry continuously increasing heavy loads on a soft shaft, whereas it could do so on a hard shaft, but more important still he shews his EX.70. metal carrying this load on soft and hard shafts with considerably less heat and friction, but still shews an improvement with the hardened shaft. Have we tried this metal (Hall's EX.73.) in any heavily taxed big end bearing such as the C. I. unit? If not, we ought to do so. (1) | ||