Signalling as1

Question 1

What 2 signalling systems are found on the NR network?

Answer 1

1. Semaphore
2. Coloured light

Question 2

What is the purpose of signalling on the railway?

Answer 2

To safely allow the passage of trains, ensuring a safe distance is maintained between trains

‘One train, one section, one time’

Question 3

Define the following signals
1. Stop signal
2. Distant signal

Answer 3

1. A stop signal displays a red aspect. Red = stop, do not proceed, danger.
2. 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.

Question 4

How does the signaller monitor trains on an, Absolute Block System (ABS)?

Answer 4

Bell-codes, buzzers
Tokens and staffs

Question 5

How does the signaller monitor trains on a, Track Circuit Block system (TCB)?

Question 6

Draw a semaphore STOP signal in the ON and OFF positions. Explain what both indications mean.

Answer 6

On = STOP, Signal at Danger
OFF = Proceed

Question 7

Draw a semaphore DISTANT signal in both the ON and OFF positions. Explain what both indications mean.

Answer 7

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

Question 8

Draw and label a basic ABSOLUTE BLOCK SYSTEM (ABS) with TWO signal boxes.

Question 9

What is the purpose of an INTERMEDIATE BLOCK SECTION (IBS) and how will it be signalled?

Answer 9

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.

Question 10

What does the term, SERVICE BRAKING DISTANCE, mean?

Question 11

Draw semaphore shunting discs in both the ON and OFF positions.

Question 12

Draw a TWO aspect circuit block signalling sequence to the red.

Answer 12

Green - yellow - red.

Question 13

Draw a THREE aspect circuit block signalling sequence to the red.

Answer 13

Green - yellow - red

Question 14

Draw a FOUR aspect circuit block signalling sequence to the red.

Answer 14

Green - double yellow - single yellow - red

Question 15

Draw ground position lights (GPLs) in both the ON and OFF positions.

Answer 15

Question 16

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.

Question 17

What are the two types of route indication associated with colour light signalling?

Answer 17

Junction indicators

Route indicators

Question 18

What does the term, ‘PERMISSIVE WORKING’ mean and how is entry into a permissive working section signalled?

Answer 18

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.

Question 19

Name THREE ways in which SINGLE LINES can be operated?

Question 20

What is the purpose of a SPAD indicator?

Answer 20

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.

Question 21

Draw a CONTROLLED SIGNAL identification plate.

Answer 21

Black background
White writing