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).
Letter from Small & Parkes Ltd. detailing co-efficient of friction test results for No.1 Asbestos Metallic 'Baraut' brake lining.
| Identifier | ExFiles\Box 26\4\ Scan152 | |
| Date | 10th December 1921 | |
| Copy of letter received from:- SMALL & PARKES LTD., Hendham Vale Works, Manchester. Ref.-RTC/NF. 10th December.1921. Messrs.Rolls-Royce Ltd., Nightingale Road, Derby. Dear Sirs, With further reference to the order recently placed with us for Brake Lining and your enquiry re co-efficient of friction, we beg to say that we had tests carried out for us by an independent laboratory, and we give below their report in connection with our No.1 Asbestos Metallic "Baraut":- "The Brake Lining was pressed on to the circumference of a water cooled pulley, the pressure being about 6-lbs. per sq. inch. The pulley was driven by an electric motor, the efficiency of which was measured. From these figures the co-efficient of friction between the Brake Lining and the metal pulley was calculated, and the results are given below. Before making the actual test, each sample was well run in, so as to get a good bearing surface on the Lining:- Sample. Thickness. Peripheral speed. Co-efficient of friction. (1) "Baraut" Lining. 1/4 inch. 1,400 ft.per min. 0.44 " 1/4 " 1,800 " " " 0.44 (2) " 5/16 " 1,400 " " " 0.41 " 5/16 " 1,800 " " " 0.42 It was found that the temperature of the Lining whilst running was approximately 2450F." We might say that during the process of manufacture of our Brake Lining, it is subjected to a standard temperature (contd.) ENCLOSURE Nº 753 JUSTSO | ||