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 policy change to abandon the use of security bolts with Dunlop or Michelin cord tyres.
| Identifier | ExFiles\Box 53\1\ Scan117 | |
| Date | 9th August 1922 | |
| Hs {Lord Ernest Hives - Chair} X4546 W/RP. c. EP. {G. Eric Platford - Chief Quality Engineer} c. Hs. {Lord Ernest Hives - Chair} c. S.Dept. RECEIVED AUG 10 1922 BY {R.W. Bailey - Chief Engineer} /LL/H. 9. 8. 22. DUNLOP OR MICHELIN CORD TYRES. RE SECURITY BOLTS. ----------------------- Referring to D {John DeLooze - Company Secretary} /BF/WHS/OG. 8.8.22. our attitude towards the use of security bolts has been modified altogether in connection with cord tyres. The actual position is that with cord tyres, the standard security bolt is not only practically useless, but is a positive danger. The Experimental Dept. who are carrying out experiments, are of the opinion that our policy in regard to security bolts will be modified altogether in the course of a week or so. The Dunlop Company and the Michelin Co. both definitely state that security bolts are useless and increase the danger of a blow-out when used with cord tyres, and our Experimental Dept. have confirmed this view, and are putting forward a proposal to abandon the use of security bolts. In the meantime I do not think it desirable for us to order further supplies of security bolts, but to arrange for cars to be despatched in the future without security bolts at all. Where holes have been bored in the rims, dummy bolts should be fitted, the position being that we propose definitely to let the Tyre Companies take full responsibility for the tyres, and to act upon their proposals that security bolts must not be used, under which conditions, if anything peculiar happens to the tyres, we shall have the Tyre Companies to fall back upon. BY. {R.W. Bailey - Chief Engineer} | ||