He and Derek Buist, a former signaller and now Network Rail operations manager for West Country South, offer a demonstration of the kind of action that would be going on in here. Levers are numbered and coloured according to their roles – red works the signals; black works the points and blue locks them; black and blue does a combination of the two. Yellow, meanwhile, activates distant signals to give drivers advance warning of stop signals ahead. Many levers are pulled down in combinations to enable specific functions.
