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).
Analysis of a switchbox's condition after 27,700 miles and considerations for its future use on an experimental car.
| Identifier | WestWitteringFiles\T\2July1929-December1929\ Scan173 | |
| Date | 30th November 1929 | |
| EEC1/AD30.11.29 contd. -2- "This switchbox has run 27,700 miles fitted with blade chamfered to give field break first. It has now been removed for disposal of the car. The field contact fingers are very slightly burnt on the corners, and the armature fingers a little more so. Otherwise the fingers are clean and good. The blade is also just marked on the contacting corners. The sequence of break still holds good, though the overlap is not a very great amount. Generally, the condition of the switch is considered satisfactory though not quite as perfect as would no doubt be realised were a longer delay before breaking the armature circuit possible". Now that the long distribution board with incorporated green lamp unit is not adopted for standard for the time being, and that therefore the connection complication does not arise, it seems expedient to reconsider the use of the switchbox with extended armature contact as originally designed for S.S. We are therefore arranging to put one of these on an experimental car. Another point arises, namely the relative position of the field and armature fuses on the distribution board. On the standard board the armature fuse is nearer to the cut-out. It was originally arranged so, no doubt, because | ||