Designation of Signals:
Signals are necessary to provide the required space interval between the trains. Signals are necessary to control the entry of trains into the block sections, into the stations and within the stations for different purposes. Signals are designated describing the function of the signals.
APPROACH SIGNALS :
- Signals provided for receiving a train is known as “Approach Signals”
HOME SIGNALS :
- Stop signal at the approach of a station. It gives entry to the housing point i.e., station.
BRACKETED SOME SIGNAL :
Where there is more than one line, each line is provided with Home Signal. All such Home signals are bracketed on a common post or a gantry.
ROUTING SIGNAL :
In cases, more than one receiving line may be available for different groups. The distance between home and station stop may be longer.
May have different places for the trains to stop. These are called Routing signals.
OUTER SIGNAL :
Where the reception of train is controlled by more than one signal, then the first stop signal (FSS) is called the Outer Signal and the second stop signal, Home signal.
An outer signal can also be placed above a Warner signal on the same post.
PERMISSIVE SIGNAL: Warner/ Distant
There may be adding one or more permissive signals to pre-warn the presence of a stop signal. in two aspect signals, we have Warner signals on independent posts.
In multiple aspect signaling, we have distant signals.
In case more than one distant signal is used, the second one as approached by the driver is called Inner Distant (Provided in some multiple aspect signaling sections).
Signals are also provided to control departure of trains. The signals authorize the drivers to start the train and also enter into next block section. If only one departure signal is provided, they are called Starter signals, they also control the entry into next block section.
If more than one stop signal controls the movement of trains to start and enter into next block sections, then the last stop signal is called ADVANCED STARTER signal which controls the entry into next block section other Starter signals are provided near the fouling marks.
In some stations, more than one-dispatch signals are provided and this signal between starter and advanced starter is called Intermediate starter signal