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).
Road spring breakage statistics from tests on various car models in France.
| Identifier | ExFiles\Box 180\M3\M3.4\ img015 | |
| Date | 1st September 1924 | |
| R.R. 403A (40 H) (SL 42 19-7-23). J.H.D. EXPERIMENTAL REPORT. Expl. No. 9410 2628 REF: Hs{Lord Ernest Hives - Chair}1/L.C5. 9.24. ORIGINAL ROAD SPRINGS, BREAKAGE STATISTICS STD, 12.5% 25% ON ROAD TEST & BUMP RIG To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to HE. E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} DY.{F R Danby} c. to Wor.{Arthur Wormald - General Works Manager} In judging the results of tests which have been run in France on 4-wheel brake cars and springs, it should be remembered that we have no records of similar tests on the standard 40/50 HP. which could compare in severity. We have never submitted a standard car to anything like such arduous tests. The best records of spring failures on standard cars to compare are those we get from our Paris Depot - they report that 40/50 HP. cars which are run hard in France have frequent trouble with front spring breakages. There have been a number of front spring failures in France before the cars have run 5,000 miles. When we were running the standardisation tests on the 20 HP. car in France, no 20-HP. car ever completed 10,000 miles without a spring failure. The average life was approx. 5,000 miles. Tests on the 20 HP. car were hardly so severe as those which have recently been carried out on the 40/50 HP. On the tests with the 25% springs which were run in France, three cars completed the full 10,000 miles without a spring failure. The failures which occurred on front springs occurred after the following miles - 13,000 - 17,000 - and 19,000 approximately. The 12-1/2% front springs which were run in France - contd :- | ||