![](https://coimages.sciencemuseumgroup.org.uk/494/323/large_thumbnail_1994_7263.jpg)
Telegraph block instrument
Telegraph block instrument, calling-on signal arm repreater, london Midland & Scottish Railway, in bakelite case
Details
- Category:
- Signalling & Telecommunications
- Object Number:
- 1995-7124
- type:
- instruments
- credit:
- British Rail, Clapham