Signalling

Question 1

Define Track Circuit Block

Answer 1

A means of detecting trains occupying a track circuit block

Question 2

Define absolute block

Answer 2

Signallers will only allow one train to enter the block section at any one time with block instruments

Question 3

What does the prefix on a signal plate tell you?

Answer 3

Controlling signal box or line of route

Question 4

What is the meaning of a proceed aspect on a semaphore shunting signal?

Answer 4

• proceed at caution to the next stop signal/buffer stops +
• be prepared to stop short of any vehicle/obstruction

Question 5

What other indications could you receive when a semaphore subsidiary signal is cleared?

Answer 5

• S = shunt ahead
• W = warning

Question 6

Why is indication of route is provided at junctions?

Answer 6

• to check whether route is correct
• to warn the driver to slow the train over the points

Question 7

Two examples of semaphore junction signalling

Answer 7

• stepped
• stacked

Question 8

Two examples of colour light junction signalling

Answer 8

• route indicator
• junction indicator

Question 9

What does this signal mean?

Answer 9

• limit of shunt - no part of train past this point unless authorised
• arrow - points to line it applies to

Question 10

What are your actions if you saw an illuminated SPAD indicator?

Answer 10

• stop train with emergency brake
• contact signaller ASAP

Question 11

What is the purpose of an OFF indicator

Answer 11

To allow guard/platform staff to see if associated signal displaying proceed aspect before giving RA to driver

Question 12

Two ways a singe line can be controlled

Answer 12

• Token system
• Tokenless track circuit block system