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).
Bumping tests conducted on various car springs, discussing material composition and design modifications.
| Identifier | ExFiles\Box 52\2\ Scan055 | |
| Date | 6th September 1922 guessed | |
| COPY. ROLLS-ROYCE SPRINGS. On visiting Messrs.Rolls-Royce Ltd. on Tuesday, September 5th, we were informed that the bumping tests were as follows:- Spring No. Brinell Hours run 1st Off side (R.5) 388 8 2nd " " (B.1) 415 16¼ 3rd " " (C.1) 415 17¼ 4th " " (A) 388 9¼ 5th " " (A.1) 415 7 1st Near side (R.6) 401 15¾ 2nd " " { B } 415 23½ 3rd " " { C } 415 18¾ The average of these tests is equal to the average of tests obtained from Springs made by Messrs.Woodhead. The variation in time, however, was far more variable than Messrs.Woodhead's, and it was in all cases the top leaf of our Springs which broke. It was decided, as these Springs were made of Chrome Vanadium, to fit new top leaves in Silico Manganese Steel, and return them to Messrs.Rolls-Royce. In order to demonstrate as to whether the Silico Manganese Steel is of a more reliable nature than the Chrome Vanadium. As these Springs will only be used for bumping tests, it was agreed that half the Springs should be with both eyes rolled, and half with one solid eye. Considering this after the meeting, we have thought it advisable to make the whole of the Springs with rolled eyes. A letter to this effect has been written to Messrs.Rolls-Royce. One eye, however, must be in the centre of the leaf, otherwise it will not fit their frame. It was also arranged to chamfer off the leaves more than at present, as these had shown signs of digging in at the points. Little advantage appeared to be gained by grinding, and it is quite probable that this will be dropped altogether so as to enable a slightly convex bar to be used, which fits better on the edges, ours not fitting so well as Messrs.Woodhead's. It is highly probable that Messrs.Rolls-Royce will require the Springs in question about the middle or end of October, and it is considered advisable to immediately have rolled a stock of Steel for this purpose. We left with Messrs.Rolls-Royce a copy of Dr.Hadfield's Report R.L.9186, giving particulars of the 700 lb. Front Springs. With reference to their letter of August 31st, asking us to put in hand 4 pairs of 600 lb. Springs, it was decided to (contd) | ||