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).
Tests conducted in France on 12½% springs for a 40/50 HP Landaulet.
| Identifier | ExFiles\Box 72\3\ scan0091 | |
| Date | 23th August 1924 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to RG.{Mr Rowledge} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} X9410 Hs{Lord Ernest Hives - Chair}3/LG23. 8.24. TESTS IN FRANCE ON 12½% SPRINGS. X9410 X.9941 These springs are being tested on chassis 9-PK. (40/50 HP. Landaulet) in France. The O.S. front spring failed after 6,200 miles. The second leaf from the bottom was found broken where it is held by the patent 'D' clip, and the 3rd. leaf from the bottom was found broken 4" from its front end. A new spring was fitted. At 6,900 miles, the N.S. front spring failed - the top leaf was broken 11½" from the rear end. We have been carrying out tests on the bumping rig with these springs; so far we have had one spring fail after 15 hrs. - top leaf, another spring failed after 17 hrs. - top leaf. The average life is approx. 18 hrs. The spring question is complicated because of the fact that we are receiving springs from two suppliers. We pointed out very early on that if it was intended to use Firths springs, we must use them throughout the tests on 4-wheel brakes. On the first test, Firths springs were fitted although the top plate was forged by Woodheads and the Woodhead type clip was used. Those springs were used for the first scheme of 4-wheel brakes and on the bumping test - they were practically all used up on the bumping test. No more springs were obtained from Firths for a time and nearly all the recent tests in France [crossed out] have been run with contd :- | ||