Home and departure signals are called absolute signals. These signals display signals when protected sections contain turnouts or other devices and the route is open in the correct direction and when there are no trains or other vehicles in protected areas.
On the other hand, block signals display signals only when there are no trains or other vehicles in protected areas, and are called permissive signals to differentiate them from absolute signals in terms of operation. Therefore, identification markers are attached to block signals.
After a train has been stopped by the stop signal of a block signal for a certain time (about one minute), the train can be operated past the signal at a speed of 15 km/h or less.
(3) Signal aspect and signalling systems
The signalling method and instruction speeds for three position signals are listed below.
The basic signalling system consists of R, Y and G, with YY and YG added as necessary.
* Proceed signal (G): Maximum speed for the section