“Trailer Board”

A little bit like what you find in Air Traffic control, where they have the backup wooden blocks, with pieces of paper, with Aeroplane details written on them.
In this case, it’s the trailer locations, so we know roughly where they all are in case of power cut for example.
We’ve had a few power cuts over the years aswell, and this board has been quite an indispensable piece of kit:)
Kind regards
Gav