Secret internal memorandum discussing the failure of front axle pivots and proposals for increasing their strength.
| Identifier | ExFiles\Box 101\1\ scan0006 | |
| Date | 6th April 1925 | |
| X.5420 To R. {Sir Henry Royce} from DA. {Bernard Day - Chassis Design} c. to CJ. HS. {Lord Ernest Hives - Chair} S E C R E T. DA {Bernard Day - Chassis Design} 1/M6.4.25. I N D I A. {Mr Adams} FRONT AXLE PIVOTS. X.5420 With reference to Hs {Lord Ernest Hives - Chair} 2/LG3.4.25., we should like to point out that the .150 radius in the bolt recess which was used on the pivot that failed was not instructed by WW. The design shews a .325 radius. We protested when [strikethrough]the matter[/strikethrough] we saw this small radius some time ago, and on going into the matter with BY. {R.W. Bailey - Chief Engineer} we decided to increase the radius as much as seemed possible at the time, namely, to .375. We also protested again when we saw the pivots [strikethrough]now[/strikethrough] with the .150 radius being prepared for bumping. In view of the short life however of this defective pivot we thought it would be advisable to see what could be done to increase the strength, and we have sent to Derby N.Sch. 1976 shewing three suggestions for increasing the strength. (A) shews what we should be getting now with the correct pivots which are being bumped. The suggestion at (1) is probably the most suitable for trying first. In the suggestion at (2) the boss could be carried right up the bolt recess until it emerged at the recess in the pivot which would of course make the corner enormously strong. But as the metal on the pivots which is being bumped should be nearly twice as much as on those which failed it is possible that they will be all that is required. It will be seen that the increase in the radius of the bolt corner also strengthens the strip of metal which forms the brake carrier. DA. {Bernard Day - Chassis Design} | ||
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).