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 and conclusions on different brake linings to resolve braking issues like squeaking and drum scoring.
| Identifier | ExFiles\Box 26\4\ Scan382 | |
| Date | 10th May 1929 guessed | |
| - 2 - (6) On severe application down the "Trail" etc. the brakes have been deliberately made very hot, but beyond a slight smell of rubber there has been no noticeable effect on the linings. So far therefore the J-M linings appear to offer a complete cure of our braking troubles, but we are now going further to try to find their limitations. MX{John H Maddocks - Chief Proving Officer}-5. Meanwhile, because our unit pressure on the linings is high compared with general practice, and at our own suggestion, the makers are sending us a set of harder linings. These we shall fit immediately on MX{John H Maddocks - Chief Proving Officer}-5, and compare results with MX{John H Maddocks - Chief Proving Officer}-4. Further Test. As soon as we have sufficient mileage on the two cars to get a good comparative idea of the two linings, I have recommended that we should place an order for 25 sets of the preferred linings and fit as rapidly as possible in the depots to cure complaints of squeaking. The drums must have all score marks removed in each case and we have equipment in N.Y. and at Waltham Avenue to do this. By the time we have representative mileage results on these 25 cars, we shall have full mileage on MX{John H Maddocks - Chief Proving Officer}-4 and 5, and shall be able to circulate a standardisation sheet. General Conclusions:- (1) The J.M. linings appear free from squeaks. (2) We know little yet about the effect of severe heating. (3) Although the first set of linings is of the softer type, wear appears slight because of lack of scoring of drums. It is pointed out that our service cost on brakes at present is far greater for rectification of scored drums than for fitting new liners. OY. | ||