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).
Test report on the performance and wear of brushes compared to standard grades.
| Identifier | ExFiles\Box 165\6\ img176 | |
| Date | 8th December 1924 | |
| RR 228 (150 BKS.) (DD 461-8-12-24) NP 306975 ROLLS-ROYCE LTD. INSTRUCTIONS. To ___________ Order No._________ Customer's No.__________ Blackened and somewhat burnt. It became so, fairly early in the test. The polish of the brushes has also lasted throughout the run. Commutators acquire a better condition than in this case when using our standard grades of brush. The brushes ran quietly throughout. The wear is as follows: Positive .021" Negative .018. Control .021. This is probably slightly more than the average obtained with the standard grades. Unless these brushes prove to be consistently quiet under all normal running conditions, they would appear to possess no advantage over the standards. Signed: F.A. This Sheet must be filed on completion of the work. | ||