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).
The testing of two different types of rear springs, detailing the failure of one set due to cracked leaves.
| Identifier | WestWitteringFiles\E\June1920\ Scan4 | |
| Date | 10th June 1920 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c.c. to CJ. c.c. to H.{Arthur M. Hanbury - Head Complaints} c.c. to L. c.c. to Da.{Bernard Day - Chassis Design} c.c. to BY.{R.W. Bailey - Chief Engineer} ORIGINAL. 9.FC. X.3981. RE REAR SPRINGS. X.1331 X.2628 We are at present testing on the bumping rig a pair of the latest type rear springs. These are the springs with the parallel end to the leaves except for a large radius and tapering in thickness at the ends. So far they have given no trouble and from the appearance of the leaves, the loading at the end of the plates is spread over a very much larger area. We could not see any signs of the end of the plate digging into the next. Whilst we were waiting for these springs we have run on the bumping rig another set of rear springs - these were the thick leaf type with the ends tapering in thickness. The sheared end of the leaves was made so that the ends of the leaves were wider. These springs were made without nibs and slots. We found after 20 hours running that the spring on the C.S. of the chassis had four leaves cracked. The fractures had taken place in the same place as we have had them before when we have had no nibs and slots i.e. under the shackle clips. We found in this case that the top short plate was broken - the second plate was practically broken - the 3rd. and 4th. plates had started to crack. It appears from the fractures that the top plate is the first one to go and this increases the stress on the other plates which break in turn. Hs.{Lord Ernest Hives - Chair} | ||