Obstruction of the line

Question 1

What is the bellcode for obstruction danger; also is it with or without call attention? (1) TS1-2.1 and TS3-4.1

Answer 1

6, without call attention.

Question 2

How many lines does obstruction danger block? (1)

Answer 2

All lines.

Question 3

For what conditions must you send obstruction danger? (2) TS3-4.1

Answer 3

Obstruction.
Emergency.

Question 4

When do you not need to send obstruction danger? (2) TS3-4.1

Answer 4

You do not need to send obstruction danger if the obstruction is only affecting the line for trains heading towards you from the Signal Box in rear and:
- The obstruction is beyond the clearing point, or
- There are facing points that you immediately set for another direction clear of the obstruction and the line is clear up to and including the clearing point.

Question 5

What position can the block indicators be in before sending obstruction danger? (1) TS3-4.1

Answer 5

Any position…you must do this whether or not you have received is line clear or train entering section.

Question 6

What are the four occasions you must send obstruction danger if you become aware of a train approaching? (4) TS3-4.1

Answer 6

Train entering section not received.
Is line clear not acknowledged.
4-5-5 not received.
Shunting into forward section not acknowledged.

Question 7

What are your immediate actions when sending obstruction danger? (3) TS3-4.2

Answer 7

Place or keep block indicator to train on line until the obstruction has been removed (with reminder).
If necessary, place or keep signals at danger to protect the obstruction (with reminder).
If necessary, arrange for train radio message to be sent.

Question 8

What must you come to a clear understanding about with the Signaller whom you sent obstruction danger to? (2) TS3-4.2

Answer 8

You must reach a clear understanding of those lines that must remain blocked and those that can be re-opened for trains.

Question 9

After sending obstruction danger, what bellcodes could the other Signaller reply with? (2) TS3-4.2

Answer 9

6 - Obstruction danger.
4-5-5 - Train or vehicles proceeding without authority in the right direction.

Question 10

What would your actions be if, after sending obstruction danger, it was acknowledged with obstruction danger? (1) TS3-4.2

Answer 10

Nothing…no train has entered the absolute block section.

Question 11

What would your actions be if, after sending obstruction danger, it was acknowledged with train or vehicles proceeding without authority in the right direction? (2) TS3-4.2

Answer 11

Take all possible actions to stop the approaching train; once you have taken all possible action, reply to 4-5-5.

Question 12

What must you do and what must you not do if you receive cancelling from the Signaller in rear for a train which had been accepted before you sent obstruction danger? (2) TS3-4.2

Answer 12

Must : Acknowledge cancelling.
Must not : Move block indicator to normal; block indicator must stay at train on line until 2-1-2 has been sent.

Question 13

What are your immediate actions when receiving obstruction danger? (3) TS3-4.3

Answer 13

Immediately place or keep all signals leading to Signal box in advance at danger (with reminder).

Place or keep the block indicator for the line from advance Signal Box at train on line and keep it in this position until you are sure the line is clear and you have sent 2-1-2.

If necessary, arrange for train radio messages to be sent.

Question 14

If you can’t stop a train heading towards the Signal Box who sent you obstruction danger, or there is already a train in the section, what bellcode must you send to the Signal Box in advance when replying to their obstruction danger? (1) TS3-4.3

Answer 14

Reply with 4-5-5 instead of 6.

Question 15

If you can stop a train heading towards the Signal Box who sent you obstruction danger before it entered the absolute block section, or there was no train signalled in the first place, what bellcode must you send to the Signal Box in advance when replying to their obstruction danger? (1) TS3-4.3

Answer 15

Reply with 6.

Question 16

If you succeed in stopping a train from entering the absolute block section, heading towards the Signal Box that sent you obstruction danger, after replying to their obstruction danger, what bellcode must you then send? (1) TS3-4.3

Answer 16

3-5 : cancelling.

Question 17

When may you allow a train to proceed towards a Signal Box in advance after obstruction danger has been received? (2) TS3-4.3

Answer 17

You must not allow any train to proceed towards the Signal Box in advance until you have received obstruction removed and the Signaller at the advance Signal Box has acknowledged is line clear.

Question 18

When must you use blocking back inside home signal with regards to obstruction of the line regulation? (2) TS3-4.4

Answer 18

If it is necessary to alter the facing points at a junction to allow a train to pass over the junction from another direction and the obstruction will then be within the clearing point, you must first protect the obstruction by sending 2-4.

Question 19

Other than obstruction of the line, what are the other occasions for using blocking back inside the home signal? (4) TS3- 3.6.1

Answer 19

Any movement that will be stopped on the running line in the clearing point.
WASL within the clearing point during a Line Blockage.
Worksite marker board in the clearing point during a T3 possession.
An out-of-gauge movement in the clearing point.

Question 20

What is the bellcode for obstruction removed, also is it with or without call attention? (1) TS1-2.1 and TS3.4.5

Answer 20

2-1-2, with call attention.

Question 21

If you were to send obstruction removed, how many lines would that open? (1)

Answer 21

One; 6 bells blocks all lines, but each line needs re-opened individually.

Question 22

What must you do when the obstruction has been removed or a train can pass clear of the obstruction? (2) TS3-4.5

Answer 22

You must send obstruction removed to the Signal Box in rear and place the block indicator to normal.

Question 23

During normal signalling, after observing a tail lamp, when may you send train out of section? (3) TS3-3.2

Answer 23

When the train has passed beyond the clearing point.
When the train has passed beyond a facing junction and you have set the points for another line which is clear to the clearing point of that line.
When the train has been shunted clear of the running line.

Question 24

If the Signaller at the Signal Box in rear was unable to stop a train from entering the absolute block section, when can obstruction removed be sent? (3) TS3-4.5

Answer 24

When the obstruction has been removed.

When the train is beyond the clearing point (or as stated in TS3-3.2).

When the train is complete with tail lamp.

Question 25

When do you send train out of section for a train that entered the absolute block section and became part of the obstruction? (1) TS3-4.5.

Answer 25

NEVER