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).
Report citing three case studies from the Dunlop Company regarding tyre failures and the effectiveness of security bolts.
| Identifier | ExFiles\Box 53\1\ Scan140 | |
| Date | 14th September 1923 | |
| BYS-F14.9.23. contd. - 2 - The security bolt may delay the time when the tyre leaves the rim by seconds, but not more. In proof of the facts put forward in the last paragraph, the Dunlop Company cited;- A {Mr Adams} /- A recent case reported in the Autocar of September 7th on page 426 at the bottom right hand corner in which the Hispano Suiza, driven by Boyriven skidded on a tram line, and although a system of continuous security bolts was fitted,(of which the Dunlop Co. have positive knowledge) the tyre was wrenched clean off the wheel, and as the report states a spectator was killed by being struck by the flying tyre. B/- In the second case they quoted the Chief Tester of a motor car firm, was running, as we ourselves do, without security bolts, the cover was wrenched off the wheel. A new tube was fitted and the cover replaced with the same result. Thinking that the solution of the question was the use of security bolts he fitted a third tube and refitted the cover, this time using the full complement of security bolts, the cover again wrenched itself clear. The Tester then reported the case to the Dunlop Company, as a fault in their tyre construction. They asked him to bring the cover and tubes round to the Works, and at once pointed out, before any examination was made, that the Tester had made a mistake in not examining the outer cover after having a tube burst. The cover was examined and it was discovered that the point of a tack had just reached through the inside of the cover sufficiently far to produce a minute hole in the inner tube, causing slow deflation, with the consequent rubbing of the cover clear of the wheel. C/- The third case they quoted was on Mr Lanchester's own car. He had two or three covers come off and then reported the matter as a mystery he was unable to solve. The Dunlop Co. asked to have the tyres and tube submitted - he therefore drove the car round, when they were able to point out to him that whilst there was no puncture in the inner tube, nor was the cover pierced, a slow leak was taking place on the schrader valve due to it being misfitted. A correction of this fault entirely cured the trouble. contd. | ||