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 special Woodhead front springs with rubber pads, including bumper test results and weight comparisons.
| Identifier | ExFiles\Box 42\3\ Scan213 | |
| Date | 24th July 1928 | |
| To BY.{R.W. Bailey - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to Roy.{Sir Henry Royce} c. to DA.{Bernard Day - Chassis Design} Y3854 Hs{Lord Ernest Hives - Chair}/Rn{Mr Robinson}1/LG24.7.28. SPECIAL WOODHEAD FRONT SPRINGS. X248 Messrs. Woodhead put up a pair of front springs to us having rubber pads between the leaves. We attach a sketch shewing the disposition of these rubber pads. The main objection to them is that they make the spring very unsightly and fat. In this case the spring leaf was drilled to take the rubber pad which obviously weakened the leaf and fracture quickly occurred where the hole was drilled. The tabulated behaviour of the springs on test was as follows :- BUMPER TEST. After 15 1/4 hrs. O.S. 5th. and 7th. leaves broken. N.S. 7th. leaf broken. After 20 1/4 hrs. O.S. 5th. and 3rd. leaves broken. N.S. 5th. and 6th. leaves broken. After 24 1/4 hrs. N.S. 4th. and main leaves broken. The springs were of slightly lower rating than our standard 1100 lbs. but their weight was no less than 47 lbs. The weight of the standard Firths front spring is 38 lbs. We note that whenever Mr. Woodhead puts up a new type of front spring to us the weight is always approximately 25% greater than our present standard and that in spite of the amount of material in the spring we never seem to get any better spring life. contd :- | ||