Signalling as1 Flashcards
What 2 signalling systems are found on the NR network?
- Semaphore
- Coloured light
What is the purpose of signalling on the railway?
To safely allow the passage of trains, ensuring a safe distance is maintained between trains
‘One train, one section, one time’
Define the following signals
1. Stop signal
2. Distant signal
- A stop signal displays a red aspect. Red = stop, do not proceed, danger.
- A distant signal is a signal which cannot show a stop aspect or indication.
Some colour light distant signals are identified by a white triangle or the letters ‘R’ or ‘RR’ on the signal identification plate.
How does the signaller monitor trains on an, Absolute Block System (ABS)?
Bell-codes, buzzers
Tokens and staffs
How does the signaller monitor trains on a, Track Circuit Block system (TCB)?
Draw a semaphore STOP signal in the ON and OFF positions. Explain what both indications mean.
On = STOP, Signal at Danger
OFF = Proceed
Draw a semaphore DISTANT signal in both the ON and OFF positions. Explain what both indications mean.
ON = proceed at caution.
The next or ANY home signal Inc. Section sign within this ABS maybe ON.
OFF = Proceed, All home signals Inc. section signal within the section is OFF
Draw and label a basic ABSOLUTE BLOCK SYSTEM (ABS) with TWO signal boxes.
What is the purpose of an INTERMEDIATE BLOCK SECTION (IBS) and how will it be signalled?
A stop signal that controls the exit from an intermediate block section, and the entrance to an absolute block section or another intermediate block section.
Purpose = to allow another train into the section.
What does the term, SERVICE BRAKING DISTANCE, mean?
Draw semaphore shunting discs in both the ON and OFF positions.
Draw a TWO aspect circuit block signalling sequence to the red.
Green - yellow - red.
Draw a THREE aspect circuit block signalling sequence to the red.
Green - yellow - red
Draw a FOUR aspect circuit block signalling sequence to the red.
Green - double yellow - single yellow - red
Draw ground position lights (GPLs) in both the ON and OFF positions.
Draw examples of semaphore STEPPING route indications for TWO diverging routes to the left, and STACKING route indications for TWO diverging routes to the right.
What are the two types of route indication associated with colour light signalling?
Junction indicators
Route indicators
What does the term, ‘PERMISSIVE WORKING’ mean and how is entry into a permissive working section signalled?
Permissive working allows a second train to be signalled onto a running line that is already occupied so that more than one train at a time can be on the same line in a:
block section
signal section
dead-end platform line.
You may proceed with a passenger train on the authority of a position-light or semaphore subsidiary signal associated with a main aspect or stop signal if you are entering a permissive platform line.
Name THREE ways in which SINGLE LINES can be operated?
What is the purpose of a SPAD indicator?
If you see a SPAD indicator illuminated, you must:
stop the train immediately
contact the signaller.
You must carry out this instruction even if the SPAD indicator applies to a signal on another line.
Draw a CONTROLLED SIGNAL identification plate.
Black background
White writing
