Atomic Systems

I would like to ask that what is this back panel used for in semaphore signal.
In Game In Real Life

I believe it is a 'screening' board usually placed behind the signal arm to make it readily visible. Sometimes distant scenery could mask the signal
so this was a way of assisting better vision.
Regards
Tom

Sometimes if the signal was near a Bridge a white area was painted on the bridge instead of providing the Screening Board.

It can also apply to Colour Lights too - see page 103
https://www.rssb.co.uk/rgs/standards/RI ... ss%201.pdf

Peter

Ok, thanks for information.
I will be working on some semaphore signals soon.

Another one -