Track Circuit Block ( Week 1, Day 1) Flashcards
What is a Track Circuit?
A track circuit is an electrical circuit connected to the rails to detect the presence or absence of trains on a section of the track.
How does a track circuit indicate a section is occupied?
When a train enters a section, it short-circuits the electrical current, indicating the section is occupied.
What is a block section?
A block section is a division of the railway controlled by signals, ensuring only one train occupies a section at a time for safe separation.
How do signals display aspects in the Track Circuit Block System?
Signals display aspects (e.g., red for stop, yellow for caution, green for go) based on the status of the block sections.
What condition must be met for a signal to show a proceed aspect?
1.) All track circuits up to and including the overlap of the next stop signal are clear.
2.) All necessary track points within the route are set in the correct position to guide the train safely on its route.
What is an overlap in railway signalling?
An overlap is the length of track, beyond a stop signal that is used as an additional safety distance. It must be clear before the previous signal can show a proceed aspect, ensuring extra stopping distance.
What happens to signals if a block section and the overlap are clear?
The signals show a proceed aspect.
What does a signal show if a block section is occupied?
The signal shows a stop aspect, preventing another train from entering that section.
What is a Signal Section?
The line between two stop signals. This can be controlled by the same signal box or different ones.
