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 condition and performance of brushes, including a table of wear measurements.
| Identifier | ExFiles\Box 60\1\ Scan295 | |
| Date | 8th December 1924 | |
| ROLLS-ROYCE LTD. INSTRUCTIONS. To Order No. PD 57 Customer's No. segment. The surfaces of the brushes were in good condition, the positives only being blackened over about one quarter of the widths, while the control brushes were only slightly dull. There was no tendency for the brushes to stick in their holders. The amount of brush dust deposited was normal, the wear of the brushes, however, being greater. Position Positive Negative Control Inner .014" .013" .025" Outer .011" .012" .012" Finally, the machine was given a run, when it was confirmed that its output performance had been maintained, and that the brushes were fairly quiet. It appears, then, that these brushes are quieter than the standard grade, but the wear is more; while in other respects they are about equal. Signed C.A.P. This Sheet must be filed on completion of the work. RR 238 (150 BKS.) (DB{Donald Bastow - Suspensions} 461-8-12-24) MP 306975 | ||