AWS and TPWS Flashcards
1
Q
What is the purpose of the AWS?
A
To provide the driver with an audible and visual indication of upcoming signals.
2
Q
What two audible cues can be delivered by the AWS?
A
Bell or warning horn
3
Q
What does the bell signify?
A
Proceed signals
4
Q
What does the warning horn signify?
A
For danger/caution signals or dangers ahead
5
Q
What should the audible cue prompt the driver to do?
A
Look out of the window to identify what the system is warning you about.
6
Q
Once the driver has identified what the system is warning him about, what must he do?
A
Acknowledge the warning by pressing the AWS cancellation button.
7
Q
How long does the driver have to acknowledge the warning by pressing the AWS cancellation button?
A
3 seconds
8
Q
How does the train know to deliver an AWS audible cue?
A
When the train passes over a 2 sided magnet that is located 180m from the signal or danger that the system is warning the driver about. The AWS receiver located underneath the train then receives signal from this magnet.
9
Q
What are the two sides of the magnet?
A
The permanent magnet and the electromagnet
10
Q
What does the permanent magnet do?
A
Triggers the warning horn
11
Q
What does the electromagnet do?
A
Triggers the bell
12
Q
What will you receive when the electromagnet is energised and the permanent magnet is de-energised?
A
Bell
13
Q
What will you receive when the electromagnet is de-energised and the permanent magnet is energised?
A
Warning horn
14
Q
What protects AWS in the driving cab?
A
The AWS circuit breaker
15
Q
If the AWS circuit breaker is tripped, what will happen to AWS?
A
It will stop AWS from working.
16
Q
Is it possible to isolate AWS in the cab? If so, what restrictions will be in place?
A
Yes but speed restrictions will apply if this is done.
17
Q
If you are driving alone without the AWS, what is the maximum speed you can travel at?
A
60mph
18
Q
If you are driving with a competent person without the AWS, what is the maximum speed you can travel at?
A
Line Speed
19
Q
If you are driving alone in fog, what is the maximum speed you can travel at?
A
40mph
20
Q
If you are driving with a competent person in fog, what is the maximum speed you can travel at?
A
40mph
21
Q
Name 4 pieces of AWS/TPWS in-cab equipment
A
Horn speaker, cancellation button, sunflower for visual indication, TPWS panel
22
Q
What might have happened if you receive a warning horn before a signal that is displaying a proceed aspect?
A
This could be a right side failure or it could be the case that a warning board or emergency indicator is positioned in close proximity to a signal and the AWS warning applies to this and not the signal.
23
Q
What happens to the AWS magnet where it is positioned ahead of a warning board or emergency indicator?
A
The permanent magnet is permanently energised and the electromagnet is permanently suppressed so that you will always receive a warning horn for this whilst these boards are in place.
24
Q
In semaphore signalled areas, which type of semaphore signals will you receive AWS warnings for?
A
Semaphore distant signals only. Not semaphore stop signals.
25
Could you receive an AWS warning if a semaphore stop signal and a semaphore distant signal are mounted on the same post?
Yes, but the warning horn or bell will apply to the distant signal and not the stop signal.
26
Will you receive an AWS warning for a fixed distant signal?
Yes but as these signals never clear, the AWS magnet will always have the permanent magnet energised and the electromagnet suppressed so that you always receive a warning horn for these signals.
27
What are the requirements of an AWS gap area?
If the location has a line speed of 30mph or under and the layout is considered to be complex, you may not receive AWS warnings.
28
In an AWS gap area would you receive any AWS warnings?
No, you would not receive any AWS warnings.
29
If an ESR or TSR is implemented within an AWS gap area, would you receive an AWS warning for this and why?
Yes, you may do if a temporary magnet has been implemented.
30
What is a depot test magnet?
A permanent magnet used to test the operation of AWS equipment after maintenance has been carried out on it. These are normally located at the exit of certain maintenance depots.
31
What does a black sunflower indication mean?
The associated signal is showing green aspect.
This may also advise the driver that the audible warning has not been acknowledged- if not acknowledged after 3 seconds, the brakes will apply.
32
What does a yellow and black sunflower indication mean?
Advises the driver that a warning indication has been acknowledged.
33
Do you need to acknowledge AWS bells?
No, only warning horns.
34
Where is the AWS cancellation button usually located?
On the driver's desk.
35
Explain the AWS Self-Test
To ensure that the AWS and TPWS are operational, the system self-tests. When the desk is energised and the direction selector is moved into forward, the AWS horn will sound continuously and the sunflower indication will be black. The TPWS lights will illuminate on the TPWS panel. You must look up at the TPWS panel to ensure the lights are illuminated and then look at the sunflower to ensure this is unlit and then press the AWS cancellation button to acknowledge the horn. This will stop the AWS horn. You must then look at the TPWS panel to ensure that all lights are extinguished and then look at the sunflower to ensure this is lit black and yellow. AWS self-test is then complete.
36
Name 7 reasons for receiving an AWS horn and yellow and black sunflower
- In advance of any colour light signals displaying a double yellow, single yellow (steady or flashing) or a red aspect
- In advance of semaphore signals displaying a cautionary aspect
- Where there is a drop in permissible speed (if greater than 60mph line speed and at least 1/3 drop in speed)
- In advance of level crossings
- In advance of ESR and TSR warning boards
- Cancelling indicator that doesn't apply to that train
- Test magnet at depot
37
Is AWS capable of distinguishing between a red, double yellow or single yellow aspect?
No, you will just receive a warning horn.
38
Name 2 reasons for receiving an AWS bell and unlit sunflower
- Colour light signal showing a green aspect
- Semaphore distant signal displaying a clear indication
39
What sign signifies the start of an AWS gap area?
A circular sign that says 'AWS' and has a red cross through it.
40
What sign signifies the end of an AWS gap area?
A square sign that says 'AWS' inside it.
41
When travelling in the non-normal direction on a bi-directional line, will you usually receive AWS warnings?
AWS magnets will be provided for signals in the normal direction of travel and normally these will be suppressed for trains travelling in the opposite direction, so you should not get AWS warnings when travelling in the non-normal direction.
42
Where you do still receive AWS warnings for trains travelling in the non-normal direction on a bi-directional line and these magnets have not been suppressed, what would you expect to see to confirm that these AWS warnings do not apply to you?
A permanent AWS Cancellation Board
43
What does the permanent AWS cancellation board look like?
A blue backed square sign with a white cross through it (Scottish flag).
44
Where would the AWS cancellation board usually be located?
180m after the magnet to inform you that any warnings do not apply to you.
45
Do you still need to acknowledge warnings that do not apply to you when travelling in the non-normal direction on a bi-directional line?
Yes, else the brakes will apply.
46
How would you know if there are AWS magnets installed in the non-normal direction on a bi-directional line that do apply to you?
You may hear a bell first and then a horn. You will then see the AWS cancellation board after any AWS horns that do not apply to you.
47
What sign signifies the start of a section where AWS is not provided in the non-normal direction on a bi-directional line?
A diamond that says 'AWS' in the middle with a red cross through it.
48
What sign signifies the end of a section where AWS is not provided in the non-normal direction on a bi-directional line?
A diamond that says 'AWS' in the middle.
49
What are your actions upon hearing an AWS warning horn?
1) Immediately look out of the window to identify the hazard
2) Cancel the warning within 3 seconds
3) Obey the signal aspect or indication
4) Control the speed of the train to no more than the speed shown on the warning board, emergency indicator or other indicator
50
What are your actions in the event that the brakes apply due to failure to cancel AWS warning horn?
1) Ensure train comes to a stand by applying brake step 3
2) Contact the signaller to inform him that you have had a brake demand light
3) Listen for an indication that you have failed to cancel AWS and the brake demand was not prompted by TPWS - this would be a continuous horn in the cab (TPWS is silent)
4) If certain that TPWS did not trigger the brake demand, you will be able to proceed normally with signaller's permission
5) Complete an RT3185 form.
51
What form must be completed if you fail to cancel an AWS horn?
Complete an RT3185 form.
52
What are your actions if you receive an AWS warning horn and you are certain that the train has not passed over any AWS on-track equipment?
Proceed normally and report to signaller at earliest opportunity.
53
What is a right-side failure?
When you receive a more restrictive AWS warning than the signal that is in front of you. Eg: You receive a warning horn for a green proceed aspect when you should have received a bell.
54
What are your actions if you receive a right-side failure?
Report to the signaller when safe to do so.
55
What is a wrong-side failure?
When you receive a less restrictive AWS warning than the signal that is in front of you. Eg: You receive a bell for a red danger aspect when you should have received a warning horn.
56
What are your actions if you receive a wrong-side failure?
Immediately bring your train to a stand and report this to the signaller.
57
If the horn and the bell sound simultaneously when the aspect is green, is this a right or wrong side failure?
Right side failure- report when safe to do so.
58
If the bell and the horn are sounding simultaneously when the aspect is red or yellow, is this a right or wrong side failure?
Wrong-side failure- bring train to a stand and report immediately.
59
If you do not receive any AWS warning for an upcoming signal, is this a right or wrong side failure?
Wrong-side failure- bring train to a stand and report immediately.
60
What will happen to the train after experiencing a wrong-side failure?
The train will be taken out of service as a precautionary measure in case the train itself is defective.
61
What is TPWS and what is its purpose?
TPWS is fitted to all mainline trains and works with the train's AWS but works to protect the train in the event that you take a dangerous action whilst driving, aiming to mitigate the impact of this.
62
How does TPWS work to protect your train in the event that you take a dangerous action?
It works to stop the train by automatically initiating a brake demand where TPWS track equipment is fitted.
63
In the event of a SPAD, can TPWS prevent the SPAD from happening?
No, TPWS cannot prevent the SPAD but it can mitigate the impact if you do SPAD by ensuring that the brakes are applied before reaching a conflict point where the train is at risk of collision.
64
Does every signal have TPWS fitted?
No, but where it is fitted it will stop the train.
65
Name 5 locations where TPWS is fitted
1) Passenger lines at all main running signals capable of displaying a stop aspect (including some stop boards) which protect crossing or converging movements
2) At any signal capable of showing a stop aspect on a non-passenger line where that signal protects a crossing or convergence with a passenger line
3) At stop signals where conflicting movements could take place in the overlap of the next stop signal ahead
4) On the approach to buffer stops at the end of passenger platforms (located 65m from buffer stops) and will trigger a brake application at speeds greater than 10mph
5) On the approach to permissible speed reductions where the permissible speed on the approach is 60mph or more and the reduction in permissible speed is at least 1/3.
66
Name 4 instances where TPWS will initiate a brake demand and bring the train to a stand
1) SPAD without authority
2) Approaching a signal displaying a danger aspect too fast
3) Approaching a drop in permissible speed too fast
4) Approaching a buffer stop too fast
67
What is an Overspeed Sensor System/ Overspeed Loop/ OSS?
These are on-track sensors that can time the speed of trains passing from the arming loop to the trigger loop. If you are travelling at an unacceptable speed, you will receive a brake demand.
The arming loop and trigger loop are a set distance apart so that your speed can be measured.
68
When will Overspeed Loops be armed?
Only armed when a signal is showing a danger aspect but always armed ahead of drops in permissible speed and buffer stops.
69
What are Train Stop Loops/Train Stop System/ TSS?
This is mounted in the four-foot at a signal and is energised when a signal is at danger. The TSS has an arming and a trigger loop but these are located closer together and work to stop you reaching conflict points in the event of a SPAD.
70
When would a train stop loop be de-energised?
When the signal is showing a proceed aspect so that you do not get a brake demand when the signal is not at danger.
71
What will you hear if you receive a TPWS brake demand?
Nothing- TPWS brake demands are silent.
72
What are your actions if you receive a brake demand that you did not initiate?
1) Firstly look at the TPWS panel to see if a brake demand light is flashing.
2) Apply brake step 3 or the emergency brake to stop the train from rolling when the brakes release
3) Acknowledge this via the AWS cancellation button which will cause the TPWS brake demand light to go steady.
4) Contact the signaller and act on his instructions
5) Do not move the train until authorised
6) 60 seconds after activation, the brakes will release and the brake demand light will extinguish.
73
Can you wait the 60 seconds for the brakes to release, the brake demand light to extinguish and then proceed as normal?
No, this is a reset and go. You must never do this unless you receive a brake demand when approaching a buffer stop.
74
What are your actions if you receive a brake demand whilst approaching a buffer stop?
1) Firstly look at the TPWS panel to see if a brake demand light is flashing
2) Apply brake step 3 or emergency brake to stop the train from rolling when the brakes release
3) Acknowledge via the AWS cancellation button which will cause the TPWS brake demand light to go steady
4) Give the guard 2 buzzers (meaning do not open the doors, contact driver) in case they think that you are at the platform and open the doors when there is no platform there
5) Wait for TPWS to time out after 60 seconds (only occasion where you are permitted to reset and go)
6) Pull forward to the buffer stop and contact the signaller
75
What will happen if you do not acknowledge a TPWS brake demand via the AWS cancellation button?
The brake demand light will keep flashing and your brakes will never release- as soon as you acknowledge, you have 60 seconds until the brakes release.
76
What could the train be telling you if the Temporary Isolation Fault is flashing on the TPWS when conducting the TPWS and AWS self-test?
That the train has a fault in the TPWS system
That the self-test cannot be completed as you are sat over a TPWS grid in the track
77
What are your actions if you are sat over a TPWS grid within the track?
Ask the signaller for permission to pull forward slightly past the grid. Then de-energise train and re-energise it. If, after doing this, the light extinguishes, you know that there is not a fault in the TPWS system. If the light continues to flash, there is a fault and the train may need to be taken out of service.
78
What should you do if the signaller does not give you permission to move forward towards the stop signal?
You will need to wait for a proceed aspect, move forward, stop, de-energise and re-energise the train and then see if the TPWS Temporary Isolation Fault button is still flashing.
79
Where is the TPWS Temporary isolation panel located in the driver's cab?
Out of reach of the normal driving position
80
When might you need to temporarily isolate TPWS?
When you have been given authority to complete certain operational moves that would normally trigger a brake demand (eg: temporary block working, emergency special working or propelling).
81
When should you reinstate TPWS in these circumstances?
Immediately after completing the authorised movement.
82
Does isolating TPWS affect AWS?
No.
83
When would you press the Train Stop Override button?
When you receive authority to pass a single signal at danger to override the brake demand from the Train Stop System loop
84
How long do you have to pass the signal after pressing the Train Stop Override button?
20 seconds
85
When you press the Train Stop Override button, what will happen?
It will illuminate and then extinguish when the train passes over the Train Stop System.
86
What is the difference between TPWS Activation and TPWS Intervention?
If the driver applies the brake but hasn't applied enough brake before TPWS has intervened, this is considered to be a TPWS Activation.
Where the driver has not initiated any brake application and is not actively trying to deal with the issue and then receives a brake demand, this is considered to be a TPWS intervention.
