Can British friends please clarify for me what are the functions of each beeper? Horn High/Low; Signal (Looks like a bell); Guard Buzzer; Whistle;
Horn - trains were fitted with two differing tones to enable people to distinguish a train from a car. The current rule book states you should only use the low tone at whistle boards but I still use both. Signal - this is the guards buzzer. Used to give the “right away” and other bell codes by the guard to the driver. Usually two bells/buzzes together means “ready to start”. Whistle - usually a depot whistle which isn’t as loud as the main horn. Used on depots and yards as they’re sometimes placed near housing estates to avoid causing unnecessary noise.
Generally the horn is used where there are whistle boards (I believe historically the two tones are because they carry over distance differently) signal bell and guards buzzer are communication between the guard and driver. There is a buzzer code for this (and the driver usually repeats back the guards signal for confirmation) http://www.railwaycodes.org.uk/features/buzzer.shtm seems to be fairly accurate whistle/depot whistle is generally used in depot settings, it’s quieter than the horn but loud enough to alert workers the train is about to move.
