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).
Investigation into coil failures caused by overheating of the immersion wax.
| Identifier | ExFiles\Box 24\2\ Scan298 | |
| Date | 8th December 1924 | |
| ROLLS-ROYCE LTD. INSTRUCTIONS. RR 238 (150 BKS.) (OB 461-8-12-24) MP 200975 (2) To Order No. (WD{Mr Wood/Mr Whitehead}14 cont'd) Customer's No. 19 the spark gaps. We suspected that the wax when the coil was immersed had been subjected to too high a temperature allowing cracking to take place which would cause slight carbonization. The wax was therefore melted and emptied out of each coil case, and it was noted that the wax was quite discoloured brown instead of white. The PWF1 coil was also found to be wrapped round with cotton tape and this was removed as it was considered to be contributory to the secondary weakness. Each coil was then tested again at 100°C and an improvement (cont'd) Signed (cont'd) This Sheet must be filed on completion of the work. | ||