Why the big red dot?

It's not because Clachnaharry is twinned with Yokohama. (It isn't.) When the swing bridge is open, the big red dot will appear in front of any train driver who has missed a signal. It is the ultimate signal, meaning STOP! No-one has ever driven into it. My extra shot is of a tall boat. It had a very tall mast, which you will just have to imagine.