Signalling General Flashcards
What are the two types of train movements?
Running Move and Shunting Move
What speed are shunting moves?
Typically low speed at <40kph
What are Home signals?
Control entry of trains into the station
What are distant signals?
Warning signals and placed braking distance from the home signals.
If driver has good visibility of home signal, what can be used alternatively to a distant signal?
Beacons
What are Starter signals?
Signals that allow the departure of a train from the station.
What aspects does a Distant signal normally have?
Caution (Yellow) and Proceed (Green)
What speed does a flashing yellow indicate a driver should travel at?
40kph
What are the three important requirements from points before a signal can be cleared over them?
Set, Locked and Detected
What is the lowest a track circuit drop shunt should be?
0.5 ohms
What track circuit should be used for a track with very low usage?
Impulse Track Circuit
Maximum track circuit length for jointless track circuits?
600-700m
What is the warning time provided to pedestrians at Level Crossings?
28 seconds
What does ELD stand for?
Earth Leakage Detector
What does HRC stand for?
High Rupturing Capacity (fuse type we use)
What does MEN stand for?
Multiple Earthed Neutral
What does MOV stand for?
Metal Oxide Varistor
What does RCD stand for?
Residual current device?
What is the device called with RCD and CB in one?
RCBO
What does SRF stand for?
Surge Reduction Filter
Where is Super Control used?
When a signal is within 60 metres of a level crossing. Super Control operates a signal even when the signal is at STOP.
What is an FR and what is it used for?
FR is a Traffic Relay and is used to show no opposin routes have been called, the opposing block direction has not been given and there is no traffic coming in the reverse direction.
What is a BR and what is it used for?
BR is a Block Control Relay. When energised, it proves no opposing routes have been given (as opposed to given, as in the FR).
What is an FSR and what is it used for?
Traffic Stick Relay indicates a train is on the block.
What is ALSR and what is it used for?
Approach Locking Stick Relay. ALSR drops when activated and is used to prevent any opposing signals from being called. ALSR also locks point sin the route.
What are the stages of clearing a signal?
Expand on this later
What is a GSR and what is it used for?
GSR is the Signal Stick Relay. It proves a train has gone past the signal, which was clear. i.e. it proves the signal was used after clearing. The relay picks up when the train uses the signal.
What is a JUSR and what is it used for?
JUSR is a Timed Route Stick Relay. Checks the tracks to the next signal are clear. Drops when activated.
This relay checks the route points and tracks. It also back proves the signal to which it refers (i.e. ALSR and RPR deactivated).
What does RPR stand for?
Route Proving Relay
What does RPR do?
It shows no opposing signals have been called or given.
What does TDU stand for?
Time Delay Unit
What does a TDU do?
Provide a 4 second delay on the first track repeat relay used in an interlockig
What does TJR stand for?
Track Timing Relay
What does a TJR do?
Starts timing when the track is occupied. The relay is used to indicate a track has been occupied for a certain length of time and thus used to approach clear signals or release locking of signals and points.
What does a TFJR do?
TFJR allows a signal to approach clear up to a flashing yellow aspect.
What does a TAJR do?
TAJR allows a signal to approach clear up to an aspect other than a flashing yellow
What does ALSR stand for?
Approach Locking Stick Relay
What does an ALSR do?
It is used to prevent any opposing signals from being given and locks points in the route.
What is the normal state of the HR/DR?
Down
What is the normal state of the ALSR?
Up
What does GSR stand for?
Signal Stick Relay