The railway block signalling bell code is a system of bell sounds used in Great Britain to communicate between manually operated Signal Boxes in implementing the railway block system.
(The bell system is not used in modern power signal boxes, other than to any older adjacent signalboxes.)
The equipment consists of a plunger or tapper (rather like a Morse key) which when pressed, rings a single-stroke bell in a neighbouring box.
Although codes varied from region to region, the following shows a few selected standard UK bell codes: [1] These would be used as follows (assuming a simple exchange between two signal boxes on a plain section of line) between two signal boxes A and B.
This United Kingdom rail transport related article is a stub.