Single Line Working Flashcards
What is the rule for trains on a single line section?
Only one train is allowed at a time on the single line section.
What ensures only one train is in a single line section at a time?
There are a number of fail safes in place.
Who is responsible for ensuring the correct procedure on the single line?
It is the driver’s responsibility.
What does the signaller provide to the driver for single line operation?
The signaller hands the driver a single line staff.
What does the single line staff authorize the driver to do?
It gives the driver authority to enter the single line section to the next signal.
Can other trains enter the single line without the staff?
No, no other trains are permitted to enter the single line without the staff.
What happens when the driver arrives at the other side’s signal box?
The driver will hand the staff over.
How is the staff transferred between trains?
The staff is passed back and forth as trains go from one end to the other.
Why can the process of returning the staff be lengthy?
You must wait for a train to come the other way to return the staff.
What is an electric token?
An electric token is a system used to manage train movements on a single line section.
What happens when a train arrives at SB(A)?
SB(A) contacts SB(B) using bell and buzzer codes to ask if the line is clear.
What does SB(B) do if the line is clear?
If SB(B) accepts, they will release a token from the machine at SB(A).
What occurs when the token is removed from SB(A)?
Removing the token prevents the removal of any additional tokens from the system until it is placed in a machine.
What happens upon arrival at SB(B)?
The token is replaced into the token machine.
How does SB(B) notify SB(A) after the train is out of the system?
SB(B) notifies SB(A) that the train is out of the system.
What is the No Signaller Token System (NST)?
A system where a driver contacts a signaller to release a token (key) for a single line.
What happens when a driver arrives at a token hut?
The driver contacts the signaller asking for a token to be released.
What does the signaller do if the single line is clear?
The signaller releases the token to the driver.
What occurs after the driver removes the token?
The signaller cannot release any further tokens until the token is replaced into the system.
What must the driver do after replacing the token at the other side’s token hut?
The driver must contact the signaller to confirm the return of the token.
What does SB(A) do to check if the line is clear?
SB(A) asks SB(B) if the line is clear.
What action does SB(A) take if SB(B) grants that the line is clear?
SB(A) presses the plunger on their instrument to change the needle indication at SB(B) to show a train is coming from them.
What does SB(B) do after acknowledging the indication from SB(A)?
SB(B) acknowledges this and then the signal at SB(A) can be cleared.
What does TCB do when it detects the train’s presence?
TCB detects the train’s presence and reverts the signal to danger.
What does SB(B) do once they see the train leave the section?
SB(B) resets their instrument to normal and notifies SB(A) that the line is clear.
What is the single line working method with train staff?
There is only 1 train staff collected at Signal Box A. The train travels over the single line section with the train staff as authority and returns it to Signal Box B. Only the train with the train staff can be in the single line section.
The system is flawed if another train comes from the direction of Signal Box A, as the train staff can become stranded at the wrong end of the single line section.
What is the Electric Token Block system?
There are multiple tokens, but only one can be released from a token instrument at a time. The signaller at Signal Box A releases a token to the driver, who can pass through the single line section with it. The token is returned to Signal Box B.
As there are multiple tokens, a token can never get stranded at the wrong end of the single line section.
What is the No Signaller Token (NST) system?
There are 2 token instruments without signallers. The driver contacts a remote signaller to request permission to release a token. If a train is in the section, a token cannot be released.
At Matlock, the driver may not need to return the token at the end of the line.
What is One Train Working with Train Staff?
Similar to the Train Staff method, but used at locations where the single line runs to a buffer stop or terminating station. The driver collects a train staff from the signal box, which is the authority to proceed.
If no Train Staff is available, it indicates a train is already in the section.
What is the Tokenless Block system?
The signalling system interlocks entry signals at each end, allowing only one signal to be cleared at a time. The signaller checks that the train leaving the section is complete before allowing another train in.
Tokenless Block Sections aren’t track circuited and use bell codes for communication.
What is the Radio Electric Token Block (RETB) system?
The driver requests a digital Radio Electric Token (RET) from the signaller. If no other driver has the RET, the signaller sends it to the driver, allowing entry into the section.
The driver must inform the signaller when the section is clear to return the RET.
What is the Track Circuited Block system?
The single line section is track circuited, allowing several trains to pass in the same direction in sequence. Signals cannot be cleared in the opposite direction until the line is clear.
