Train Signal

Train Signals are used to control the flow of Trains not driven by players.

Obtaining

Crafting

Name	Ingredients	Crafting Recipe
Train Signal	Train Casing + Electron Tube	4

Usage

Placement

Right-click a Train Track with a Train Signal while facing the direction Trains are intended to go, then place the signal within 15 blocks of the selected Track. An arrow will appear on the selected Track indicating which way Trains can pass it.

Two-way Tracks

Conductors will never cross a Train Signal from the opposite direction. Unlike other Railway Equipment, multiple Train Signals can select one track. A Train Signal can be made two-way by having two opposite facing Train Signals linked to the same place. Train Signals facing the same way on the same Track will be synchronized.

Track Segments

Train Signals divide the track network into segments. The segments can be viewed by holding a Signal while looking at the Track. Conductors will not enter a track segment occupied by another Train, regardless of how large the Train or the segment is.

In order to divide a Track into sections, each section must be separated either by a Train Signal or a lack of connected Tracks. A circular loop of Tracks requires two Train Signals to divide it, otherwise the Train Signals will have no effect. A straight track only needs one Train Signal to divide it into two. If a section was successfully defined, the line ahead of the Signal should become a different color. The color has no significance aside from serving to differentiate segments.

Chain Signal

Use a Wrench on the signal to activate chain mode. In chain mode, the signal considers not only the segment the signal protects, but also the next signal beyond it (if any) along the approaching train’s route. A train can only pass a chain signal if the protected segment is clear, and the train is able to pass the next signal along the its route.

A typical use of chain signals is to protect junctions. Consider a crossing between a northbound track and an eastbound track. Four signals will be relevant, two controlling northbound trains and two controlling eastbound trains; on each line, one signal will be before and one signal after the crossing. If all four signals are in normal mode, a northbound train could enter the crossing and then stop at the second northbound signal due to traffic further ahead; when this happens, because the crossing is occupied, eastbound traffic will stop (in order to avoid colliding with the stopped northbound train), which is generally undesirable as the eastbound track is otherwise free. However, if the first northbound signal is set to chain mode, then a northbound train will not pass the first signal until the second signal is also clear; in other words, it will not enter the crossing until it is able to exit it, instead stopping at the first northbound signal and leaving the crossing clear for eastbound traffic. Generally one would also set the first eastbound signal to chain mode to eliminate the same problem with the directions reversed.

The following details apply:

• If there are multiple possible “next” signals that a chain signal could look ahead to, it will choose one based on the route the train has selected to its next timetabled location.
• The train’s route, for the purposes of calculating chain signal states, ends at its next timetabled stopping point. Thus, if the station is between a chain signal and a normal signal, the train will pass the chain signal as soon as the protected segment is clear, without caring about the state of the normal signal. This is true even if the train will subsequently continue to a point beyond the normal signal after making its station stop.
• The train’s route does not end at a timetable entry of type “waypoint through station”; the route considered for chain signal calculation only ends at a station where the train will stop.

Display

Nixie Tubes can be attached to make the signal more visible, as well as convey additional information.

• If the signal's segment is clear, the tube will glow white.
• If the signal's segment is occupied, the tube will glow red.
• If a signal is in chain mode and only some of the segments ahead are occupied, the tube turns yellow. The train can pass if the target segment ahead is not occupied.

Redstone

Signals give a Redstone Comparator signal while red. Signals can also be forced red by being activated with Redstone.

History

• 0.5: Introduced.