(Edit by Karlos aka ixiik: For simple text is not needed any tag)

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===Purpose===

<br>

==Block signals explained==

Block signals allows access only on the blocks which are not occupied by other train. Block is the space of railway between two signals. You can see the block status with the arrows pointing towards the segments. Red arrow means that the block in the arrow direction is occupied.<br>

On the right picture you can see our example station situation. Each block is located between two signals / end of the track and colored with different color. Red is the station block, blue is the entry block, green is the rest of the track. Yellow track is the exit from station. This way, one train can approach the station from the left while another train can leave from the station.<br>

You can notice that the station block is now split into two tracks with two one-way singal. One "entrance" signal, one "exit" signal. The incoming train will enter from the green block to blue block. Then the train enters the station, the red block. Next incoming train will have red sign on the entrance signal, because of occupied red block and it will wait in the blue block, while the first train will have space to leave through the yellow block. This is effective enough on the low load railroads.

===Common mistakes===

{| class="wikitable"

==Chain signals explained==

===Definition===

''Chain signal will be green if there is at least one green signal behind it.'' <br>

There are three main situations where chain signals are needed:<br>

* ''At crossings'' to prevent train from blocking the crossing, if the train cannot continue beyond it. Correctly placed signals are '''Chain before''' the crossing and '''Block after''' the crossing. If the track after the crossing is empty -> the block signal is green -> the chain signal before the crossing is green. If the block after the crossing is occupied -> the block signal is red -> the chain signal before the crossing is red as well so next train won't enter the crossing thus it will not block the traffic on the other track. For instance, imagine the upper left track leading to an off-screen loading station, and the first train is waiting its turn. The second train will not enter the crossing (and block it) while it waits behind the first train, thanks to the chain signal.

[[file:Chain_at_crossing.png|315px]]

[[file:Chain_at_crossing_red.png|300px]]