This simulation demonstrates basic Automatic Block Signal (ABS) logic operation. There are basically three things ahead of the signal head that determine its aspect: block occupancy, next signal state (or signal ahead state) and switch state. Also this simulation assumes that when a signal mast has two heads there is a switch just ahead. The upper head indicates the straight route track state and the lower head indicates diverging route track state. In addition, the signal head is shown on the right side of the track in the direction of travel.
For signal vocabulary click here.
Simulator operation – click on the block line or the switch icon in the diagrams below to change the state.
Turn phone to landscape position to view correctly.
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| Double Crossover | Direction of travel <--> | ||||||
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