Railway Signals Points and Tracks Indications
Indications can be either visual or audible.
Indications shall be provided to:
Know the status of all equipment under his control.
This includes the detection of train occupancy of the lines under his control.
Where required duplicate indications can be provided other than the signaler’s control panel for operational convenience.
Route entrance indication
- During the route initiation process, a flashing indication is to be given at the entrance button when it is pressed
- When the route is set this indication should be steady.
Approach lock indication
During the cancellation with the entrance, button pulled NR picks up and in turn energises ALKR through the back contact of ALSR. ALKR extends a flashing feed to red light indication of the signal.
As soon as ALSR picked up, ALKR de-energises, and the steady red light indication is restored on the signal.
Indications are to be provided for all controlled signals.
Indications of main aspect should include lamp proving.
ON and OFF aspect indications must be derived from the relay controlling the signal aspects.
For indirectly fed signals RGPR and H/DGPR which are controlled by HR are taken to the control center to use in signal indication circuits.
For position light signals associated with the main aspect are to be provided with an OFF indication.
For independent position light signals both ON and OFF indications are provided.
Where lamp type signal heads are provided a first filament failure indication is provided for a group of signals at the same location.
TPWS failure indications are provided to the signaller where the failure of TPWS can not revert the rear signal to ON
Signal Indication Circuits
SIGNAL INDICATION CIRCUITS(auto)
A steady white indication is displayed when signal is set for auto working
Normal and Reverse indications (white) are provided adjacent to the point key when points are set correctly to respective positions.
When points are out of correspondence with the point control relay a flashing white indication.
POINT INDICATIONS ON TRACK
No indication is shown on the track when route is not set and track not occupied.
White lights are lit on the track (entire route from entrance signal to exit signal) corresponding to the route set when track is not occupied.
Route lights extinguish when the route is released.
Red lights are lit when track is occupied irrespective of route set or not