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 comparison table of different brake shoe designs and their performance.
| Identifier | WestWitteringFiles\K\December1923\ Scan59 | |
| 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. 473 550 315 315 15 20 This test made for the sake of comparison with those below as springs were not fitted in previous tests with std. wrapping shoes. W Shoe split at toggle end - Link free at both ends. (Sketch of a split brake shoe) 473 550 315 315 6 -- Trouble was experienced with the segments fouling, not allowing the toggle end to function well - higher reading not taken due to above. X Shoe split at toggle end - Link rivetted to toggle end and free pivot end. (Sketch of a split brake shoe) 473 550 315 315 6 10.4 The braking power of this 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. Y Shoe split in centre. Diag. free link. (Sketch of a brake shoe split in the centre) 473 550 315 315 5 9 The most powerful shoe yet tried. Pivot end comes into operation first followed by toggle end on harder application of lever. Z Shoe split in centre. Horizontal free link. (Sketch of a brake shoe split in the centre) 473 550 315 315 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 X As above but Ferodo on toggle end only. (Sketch of a split brake shoe) 473 550 315 315 8 -- See sheet 3. Higher reading not taken. | ||