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 failure analysis of a coil, identifying wet varnish and charring as issues.
| Identifier | ExFiles\Box 70\3\ scan0127 | |
| Date | 9th December 1924 | |
| RR 238 (150 BKS.) (DB{Donald Bastow - Suspensions} 451-9-12 24) MP 306975 ROLLS-ROYCE LTD. INSTRUCTIONS. To...........................................................................19 Order No.......................... Customer's No.......................... wet with varnish which in all probability caused the weakness, otherwise the coil windings were OK. This coil obviously had not been dried out enough in the first place. Coil No T145X when unwound shewed signs of overheating the insulation of primary and secondary being charred although the charring appeared to be confined to the vicinity of the primary and the primary winding itself. This charring we suggest caused the weakness. These coil bobbins and cores can now be handed back to Mr Brock Signed H.E.W. This Sheet must be filed on completion of the work. | ||