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).
Comparative test report on various brake shoe designs and their performance.
| Identifier | ExFiles\Box 26\4\ Scan199 | |
| Date | 1st December 1923 guessed | |
| Type of shoe. DESCRIPTION. SKETCH. Initial drum r.p.m. Final drum r.p.m. W. REMARKS. 2A. Standard. Standard. 473 315 15 This test made for the sake of comparison with those below as springs were not fitted in previous tests with std. wrapping shoes. 550 315 20 W Shoe split at toggle end - Link free at both ends. [SKETCH] 473 315 6 Trouble was experienced with the segments fouling, not allowing the toggle end to function well - higher reading not taken due to above. 550 315 -- X Shoe split at toggle end - Link rivetted to toggle end and free pivot end. [SKETCH] 473 315 6 The braking power of tis shoe seems to be identical with shoe 'W' but in this case the bedding was uniform, both segments of the shoe being in operation at the same time. See also Sheet 3. 550 315 10.4 Y Shoe split in centre. Diag. free link. [SKETCH] 473 315 5 The most powerful shoe yet tried. Pivot end comes into operation first followed by toggle end on harder application of lever. 550 315 9 Z Shoe split in centre. Horizontal free link. [SKETCH] 473 315 8+ More powerful than std. but unsatisfactory owing to rubbing in 'off' position and link at wrong angle. Higher reading not taken due to this 550 315 -- X As above but Ferodo on toggle end only. [SKETCH] 473 315 8 See sheet 3. Higher reading not taken. 550 315 -- | ||