Single pneumatic ground disc signal, Southern Railway, by Westinghouse Brake & Signal Co, England. Single pneumatic ground disc signal
Ground disc signal, offten called a 'dolly'. Located on model railway layout, gauge 1, Lancashire & Yorkshire Railway Signalling School, built 1912, by L&YR. Model ground disc signal, Box A 1912
Yellow ground disc signal, controlling movements from Box A siding to up main. Located on model railway layout, gauge 1, Lancashire & Yorkshire Railway Signalling School, built 1912, by L&YR. Model yellow ground disc signal 1912