Wood Green No2 SB panel negative

Signal box diagram negative for Wood Green No2, for the additional panel that was provided in the 1970s alongside the mechanical frame.

Diagram negatives, in railway terms, are not "negative" in the photographic sense. They are the master copy kept at the drawing office which would be amended as changes took place so that a fresh print could be taken, coloured and issued. They are produced on a high quality linen-based drafting paper but sometimes, as in this case, alterations have caused some damage. The plan has a slight rippled effect owing to long-term tight-rolled storage.

The plan is approximately 6 feet long and will be posted rolled, in a protective tube.