Exceptions To Pass - ABS Flashcards
What are the exceptions to pass a home signal at danger in ABS system?
Defective Track circuited (Track section is occupied/obstructed) and no low speed caution or calling on signal is provided to enter the location Single line working is introduced
For a defective home signal, what authority to pass do you need to pass if the signal is protecting points or a tramway crossing?
Signallers Caution Order
For a defective home signal, what authority to pass do you need to pass if the signal is not protecting points or a tramway crossing?
Verbal instructions from the controlling signaller as the authority to pass that signal
How can a Signallers Caution Order be issued?
Handed
Transmitted
Dictated
What does Track circuited and No low speed caution is provided to enter an occupied section mean?
It means the home signal does not have a low speed caution aspect and the train needs to enter the line ahead to enter an occupied section (entering to assist a disabled train)
What is the exemption for track circuited where no low speed caution is provided?
Driver must receive verbal instructions and/or a green hand signal from the controlling signaller as the signal to pass as well as a competent employee to pilot
What is single line working?
Single line working is a system used when a single line on a double line system is shut down for repairs or maintenance
What is the exemption for single line working on abs systems?
Driver must be piloted into the section
Driver must be given time to peruse the details of the single line working operation procedures
This pilot cannot give permission to leave the single line section
What are the exemptions for passing a disc or dwarf signal?
Defective
Single line working
If a disc or dwarf signal is defective, what authority do you need to pass?
Verbal instructions or hand signaller
What authority do you need for single line working for a dwarf or disc signal
Pilots authority
How many exemptions are there to pass an automatic
2
Rule 1 section 3
Assisting a disabled train
What are the station limits for ABS?
Portion of line extending between the arriving home signal and the first automatic signal in advance of the departing home signal or when no departing home signal is provided, the first automatic signal ahead of the arriving home signal
What is the object of ABS systems?
Where two or more trains are to proceed in the same direction, to prevent more than one train being in a track section
On bi directional lines to prefect trains running in opposite directions in a single line section at a time
How is the object of ABS achieved?
By ensuring the signals to enter the section are at stop unless the track section ahead is clear
For bi directional, ensuring that if opposing directional trains are to enter that the signal is at stops to prevent head on collisions
