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 cause of fractures in the Phantom III rear brake drums, attributing the failure to grit.
| Identifier | ExFiles\Box 91\3\ scan0179 | |
| Date | 10th November 1935 | |
| X300 MARTINDALE 2 HOTEL DE FRANCE, CHATEAUROUX. Indre. France. GWH{George W. Hancock - Head Chateauroux}/2/JAB. 10th November 1935. To. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} from G.W.H. copy to E.{Mr Elliott - Chief Engineer} 3I. EX. PHANTOM III. REAR BRAKE DRUMS. With regard to E's memo E2/HP.8.II.35 The breaking of the drum edge referred to in my report of the 3.II.35. The flexing of the drum has nothing to do with the breaking. Without one tries to break his neck it is not possible to safely pull the Car up, and distort the drum to cause the fractures reported. When Hs{Lord Ernest Hives - Chair}/AFM{Anthony F. Martindale} is applying his statistic test, the load he applies to distort the drums could not be used with safety on the road. We have not carried out any hectic braking, therefore the question of distortion does not apply. The failure has been caused by grit getting in between the water excluder shield and the drum. The grit is actually small flint stones. It is not a question of large stones hitting the drums. We have heard the crunching of these small stones between the drum and shield, not after braking, but mostly, noticeable, after cornering. We enclose sketches of the drum giving the proportional fractures, also one showing the drum fouling the dust shield. [Signature of GWHancock] G.W.H. | ||