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).
And replies detailing extensive brake performance tests and material analysis.
| Identifier | ExFiles\Box 182\M18\ img110 | |
| Date | 24th August 1914 guessed | |
| DRB (Top right annotation: H.D. 21-7-13, with 11 circled above it, and red text 'out of sequence') Wsm/Hy{Tom Haldenby - Plant Engineer} to C.J. Re Bagshaw (1939 Hame we allord enf Bombes mtl/E for new brakes?) Na{Mr Nadin}- after a yr ago in response to I.S.P's request - no change since. Problem to ensure also uniformity in future. Watch by inspectors in mfg - thrown out any softer than usual. Comparison Scleroscope between old & new (old 1300 series) Diff shown, same as difference in various parts of the same shoe. Value of ?? Get a Brinell for all castings. To Shorleycliffe, connected with drum quality? Will keep in mind. ex p/s in hand which should enable us to act in definite policy & we shall not drop the matter until we know how a successful man.. (Red text on left: *** Roy{Sir Henry Royce} Repots) (Top right of this section: 112, out of registry, 20-8-14) Wor{Arthur Wormald - General Works Manager}/Hy{Tom Haldenby - Plant Engineer} - C.J. R.{Sir Henry Royce} By.{R.W. Bailey - Chief Engineer} Na.{Mr Nadin} Further tests with aircooled drums, 15" 'straps' & 2" ferodo. Copper rivets flush with friction surface. Deepened leverage & pedal pads. 3.5" Tests on track (R.R.) 3rd gear full throttle, braked (foot) down to 20 mph. Liner clearance checked before & after. 2 mile test - still in good condition. Clearances after cooling down measured. Pedal goes down slightly. Test 2 - 3 miles. Brakes fairly hot & smoking a little (not more than expected). In each case brake was good after, silent, smooth, & powerful - occasional squeak from copper rivets. Alum to be loose & few cast on test. O.{Mr Oldham} due for examination if they stood up will try full set. Test 3 - Same brake for 4 miles without adjustment, same condition. Pedal dead just goes down to floor/td, when hot stopped. Clearances measured. Think Ratio of expansion between drum & brake about right. Better to have cl. chan decreasing & risk of seizing on increasing cl than decreasing. (Red text on left: Hy{Tom Haldenby - Plant Engineer} speak / Daylight at last Hy{Tom Haldenby - Plant Engineer} a real bull) Test 3 seems to indicate the brakes OK if expansion.. if we wish we can put more into shoes by using more rivets - do not think it wise judging by tests so far. After all 3 tests, after cooling, brakes were quite powerful, quiet & smooth, but wear had caused pedal to come to atoms from floorboard (so that it contd by pushing hard, contact c/b board). After adjustment, everything again quite in good working order again. 'It is remarkable how the Ferodo stands up to stand the severe punishment'. (Red text annotation: Hy{Tom Haldenby - Plant Engineer}'s words) Straps have some distortion but efficiency doesn't seem to have been any way impaired & the wheels, with plain rubber tyres, can be locked on a dry hard smooth road. Dyno & road tests show near same results & is doing more work than off. This confirmation of parts is decidedly the best brake we have tried, & proving it from all points. Much more needed to ensure durability. By asked to get some 1/2" thick ferodo instead of 3/16" latter rather thin after bedding in. Also 2" wide straps give better results, having full width of ferodo. Castings to hand for D-straps. There are also of letter. (Red text on left: Hy{Tom Haldenby - Plant Engineer} gets 'hooked up!') (Top right of this section: 113, 21-8-14) R to Wor{Arthur Wormald - General Works Manager}/Hy{Tom Haldenby - Plant Engineer} & C.J. Na.{Mr Nadin} By.{R.W. Bailey - Chief Engineer} Reply to Hy{Tom Haldenby - Plant Engineer}'s report 21-8-14. O.{Mr Oldham} 20 mph two much to expect brakes to absorb continuously. My test 20 mph to 4th and then open. Test comparative in dyno shop. Endurance test on a private test vehicle with watercooled brakes, RR Std Control, Delaunay B, Daimler, Lanchester, & any other you have to test. Reason for limiting power absorption we can expect. Our engine on full throttle for 5-6 min in Park. Perhaps we can design straps without lightening holes - nonexpansion & substantial proportion which is preferable. More important than rivets as heat conductors. Test these also. | ||