Semaphore / AB Signalling

Question 1

What’s the area between the Distant signal and the Home signal called?

Answer 1

Serviceable braking distance.

Question 2

What’s the back of a semaphore signal look like?

Answer 2

White background with either a black line (back of home/section) or black chevron (back of distant)

Question 3

What’s a distant signal look like?

Answer 3

Fishtail board, yellow background, black chevron.

Question 4

What’s a home/section signal look like?

Answer 4

Red background, with a solid white line.

Question 5

What’s the area between the home signal and the section signal called?

Answer 5

Station limits.

Question 6

What would you find before a distant signal and how far before?

Answer 6

AWS magnet / 180m

Question 7

What stops signals being pulled in the wrong sequence?

Answer 7

Interlock

Question 8

Where is the “Block Section”?

Answer 8

Between a section signal and the next home signal. Unless there’s an Intermediate Block signal then the block section would be between the IBS and next home signal.

Question 9

How many home signals can there be?

Answer 9

4

Question 10

Why is there sometimes more than 1 home signal?

Answer 10

To break up station limits into smaller sections to allow more trains at once into station limits.

Question 11

What does IBS stand for?

Answer 11

Intermediate Block Signal

Question 12

How do you identify an IBS?

Answer 12

Signal plate with a black vertical line.

Question 13

Who controls the IBS?

Answer 13

The signal box before it.

Question 14

What is an IBS made up of?

Answer 14

1 distant signal, 1 stop signal.

Question 15

What does a white “diamond” <=> on a signal indicate and where would you find one?

Answer 15

The signal is track circuited, usually on a Home signal. (So the signaller knows you’re there.)

Question 16

What’s the little semaphore signal (sometimes found below a normal signal) called?

Answer 16

Semaphore subsidiary signal.

Question 17

What does a horizontal semaphore subsidiary signal mean?

Answer 17

Obey main signal

Question 18

What does a cleared semaphore subsidiary signal authorise a driver to do?

Answer 18

Pass the main signal at danger and proceed at caution towards…
1. The next train
2. Signal
3. Buffer stop
And be prepared to stop short of any obstruction.

Question 19

Sometimes semaphore subsidiary signals have a letter in a round circle below them. What are the letters and what do they mean?

Answer 19

C = Calling On
S = Shunt Ahead

Question 20

What does proceeding at caution mean?

Answer 20

Being able to stop safely before..
1. Obstruction
2. Train
3. Signal
4. Buffer stop

Question 21

What must you do if you get a semaphore shunt signal that has cleared?

Answer 21

Proceed at caution as far as the line is clear.

Question 22

When might you see a distant board?

Answer 22

On approach to…
1. A colour light stop signal
2. A semaphore stop signal
3. A stop board
4. A points indicator
5. A buffer stop

Question 23

What is a Fringe Box?

Answer 23

An area where coloured light signals change to semaphore signals, so Absolute Block rules apply.

Question 24

What must you do when moving over points worked from a signal box where there is no signal associated with them?

Answer 24

You must get the signallers permission make sure they are clamped and check the points fit correctly.

Question 25

How will a signaller in a signal box give permission to cross over points?

Answer 25

1. Verbally
2. Arm raises above head (daytime)
3. White light moved quickly twisting wrist
   Once cleared of points, if no shunter with you, advise signaller by one short blast of the horn.

Question 26

What must you do when you’re detained at a signal?

Answer 26

Set DRA and put brake into full service.

Question 27

What identifies a co-acting signal

Answer 27

A plate with “CA”