AWS Flashcards
What is the purpose of the Automatic Warning System (AWS)?
The AWS provides audible and visual indications to the driver regarding the status of signals/reductions in permissible speed. If the driver fails to respond to warnings, an emergency brake application will be initiated.
What components make up the AWS?
AWS consists of both track and train equipment.
What is the function of the AWS magnet?
The AWS magnet is placed 180 metres from a signal to provide you with a warning of a change of aspect head.
Where are AWS magnets not provided?
AWS magnets are not provided at semaphore stop signals, only at semaphore distant signals.
What are the types of track equipment used in AWS?
The types of track equipment include permanent magnets, electromagnets, suppressor magnets, depot test magnets, and portable magnets.
What does the receiver in the train equipment do?
The receiver detects sequences and polarities of magnetic fields from the AWS track magnets.
What does the audible indicator do in the AWS?
The audible indicator provides a bell sound if clear or a horn for warning indications.
What is indicated by an all-black visual indicator in the cab?
An all-black visual indicator means the associated signal is displaying a green aspect.
What happens if the AWS audible warning is not acknowledged?
If the AWS audible warning is not acknowledged within 2-3 seconds, an emergency brake application will occur.
How is the absence of AWS indicated in certain areas?
The absence of AWS is indicated by specific signage showing the start and end of AWS gaps.
What must be done if the AWS is defective before starting a journey from a maintenance depot?
A train must not start a journey if any cab required to be driven has a defective AWS.
What should be done if the AWS becomes defective during a journey?
The train must be stopped immediately, the signaller must be informed, and no movement should occur until instructed.
When can the AWS be isolated during a journey?
The AWS can be isolated only when cancelling the warning does not stop the horn or brakes from applying.
What are the speed restrictions if the AWS is defective or isolated?
Freight trains and OTMs can proceed at a speed not exceeding 50mph; all other trains can proceed at a speed no more than 60mph without a competent person. With a competent person it is line speed. Poor visibility means 40mph
What is the distance for placing an AWS magnet when speed reduction is required?
An AWS magnet is provided 180 metres away from the warning indicator if a permissible speed over 60mph needs to be reduced by more than a third.
What additional warnings can AWS provide?
AWS can warn drivers of level crossing warning boards, temporary speed restrictions, and emergency speed restriction warning boards.
What is a permanent magnet in AWS?
The train first encounters a permanent magnet, which gives a warning indication if an electromagnet is not provided or not energised.
What does an energised electromagnet indicate?
An energised electromagnet gives the driver a ‘clear’ indication when approaching a green signal or a semaphore distant signal showing ‘clear’.
What is the purpose of a suppressor magnet?
Suppressor magnets suppress permanent magnets when they are not required for a train movement in that direction of travel.
What is a depot test magnet?
A depot test magnet is a permanent magnet located at depots used to test the operation of a train’s AWS.
What are portable magnets used for?
Portable AWS magnets provide warnings to the driver on the approach to temporary and emergency speed restrictions.
What does the audible indicator do?
The audible indicator makes a bell sound if clear or a horn to provide a warning indication. The driver does not have to acknowledge a clear indicator.
What does the yellow and black indication advise the driver?
The yellow and black indication advises the driver that a warning indication has been acknowledged.
What is the purpose of the AWS/TPWS acknowledgment button?
This button is used to acknowledge an AWS audible warning. If it is not pressed within 2-3 seconds of an audible warning, then an emergency brake application will occur.
What signage indicates that AWS is not provided at a station?
Signage indicates where AWS is not provided at a station on a line equipped with AWS.
Start - circle Red Cross thru AWS
Finish - square with AWS
How is AWS affected on single and bi-directional lines?
On single and bi-directional lines, the AWS magnet is normally suppressed for movements for which it does not apply, and the AWS will not operate.
What indicates that the AWS warning does not apply to trains travelling in a certain direction?
A cancelling indicator is provided to advise the driver that the AWS warning indication does not apply to trains travelling in that direction.
Scotland flag if permanent
Yellow Scotland flag is TSR/ESR
Where is the cancelling indicator positioned?
The cancelling indicator is normally positioned 180 metres after passing over the AWS magnet.
What happens if you do not cancel the AWS in time?
If you do not cancel the AWS in time, the brakes will apply. You must bring the train to a stop, secure it, and then contact the signaller.
What should you do if you have an AWS fault of code 5?
You must stop immediately and report the fault to the signaller.
Code 5 indicates a bell instead of a horn.
What should you do if you have an AWS fault of code 7?
You must stop immediately and report the fault to the signaller.
Code 7 indicates no warning when approaching a signal at caution or danger.
What should you do if you have an AWS fault of code 7a?
You must stop immediately and report the fault to the signaller.
Code 7a indicates the visual indicator did not change to yellow and black.
Can you start a journey from somewhere other than a maintenance depot with a defective AWS?
You can allow a train to start a journey with the AWS defective, isolated, or with the seal broken, as long as AWS will not be required during the journey from driving at that cab.
And
If in the driving end you can go ECS, 60 mph max
You must inform control and carry out any instructions given.
What must you do to start a journey with a defective AWS to a maintenance depot?
You must notify the signaller and get permission for the train to start a journey in this condition.
What should you do if the AWS becomes defective during a journey?
You must stop your train immediately, tell the signaller, not move the train until instructed, and carry out the instructions given.
What should you do if you become aware of a defective AWS that is not required to be operating?
You must tell control at the first convenience and carry out any instructions given.
When may the AWS be isolated?
The AWS may be isolated when:
• Cancelling the AWS warning indication does not stop the horn sounding or the brakes applying.
• Successive or intermittent failures suggest that the AWS equipment is defective.
• The train stops directly over track equipment.
What must be done if the AWS is isolated after stopping over track equipment?
If the AWS is isolated because you’ve stopped directly over track equipment, you must, if possible, make sure the AWS is made operative again immediately when restarting the train.
What steps must be taken if it becomes necessary to isolate the AWS?
If it becomes necessary to isolate the AWS, you must:
• Stop your train immediately.
• Tell the signaller.
• Not move the train until instructed to do so.
• Carry out any instructions given.
What is the speed limit for freight trains and OTMs if a competent person is not provided?
Freight trains and OTMs can proceed at a speed not exceeding 50mph; all other trains can proceed at a speed no more than 60mph.
During poor visibility, the train must not exceed 40mph.
What is the speed limit for trains if a competent person is provided?
Proceed at normal permissible speed.
During poor visibility, the train must not exceed 40mph.
