Another pointless train question... Emergency Stop.
Discussion
My curiousity is unbound.
My train home yesterday took on a surprising turn when our carriage started beeping and the train did an emergency stop. Looking to the end of the carriage was a chap bopping about looking a bit frantic who then disappeared into another carriage. The guard turned up, swore and asked if anyone had jumped out of the door. She was thoroughly perturbed.
Eventually, it was worked out that the odd bloke was in a full-on panic as someone had collapsed. Rather than push the 'Speak to Driver' in an emergency button, he pulled the emergency door release. The train then stops, and according to the label a second pull opens the door. A bit of a cock up really as we would have been better heading towards Peterborough, rather than delaying things stopping. Not helped as resetting the system was not straightforward apparently.
Now I have set the scene, what happened behind us? As I understand it signals are either green, yellow double yellow and red - giving drivers a gentle warning that they need to slow down. We of course just stopped. Did some trains have to do an emergency stop to avoid running a red, or is there some slack to allow for this scenario?
My train home yesterday took on a surprising turn when our carriage started beeping and the train did an emergency stop. Looking to the end of the carriage was a chap bopping about looking a bit frantic who then disappeared into another carriage. The guard turned up, swore and asked if anyone had jumped out of the door. She was thoroughly perturbed.
Eventually, it was worked out that the odd bloke was in a full-on panic as someone had collapsed. Rather than push the 'Speak to Driver' in an emergency button, he pulled the emergency door release. The train then stops, and according to the label a second pull opens the door. A bit of a cock up really as we would have been better heading towards Peterborough, rather than delaying things stopping. Not helped as resetting the system was not straightforward apparently.
Now I have set the scene, what happened behind us? As I understand it signals are either green, yellow double yellow and red - giving drivers a gentle warning that they need to slow down. We of course just stopped. Did some trains have to do an emergency stop to avoid running a red, or is there some slack to allow for this scenario?
Train behind, if close enough, will be seeing yellows and will brake accordingly - no emergency brake application warranted as the driver will be preparing to stop anyway due to observing yellows. Driver will also know exactly where the ‘red’ signal is in relation to observing a previous yellow so will no doubt brake as normal for the signal at danger and simply roll up to it.
Bit of a ‘nothing to see here’ for the trains behind.
Bit of a ‘nothing to see here’ for the trains behind.
No signals would suddenly change behind the train that stopped so all other trains would just draw upto a red as they came to it.
Chasing aspects, where the train behind is constantly seeing yellows is poor driving and is generally avoided. If you pass a single yellow you're generally crawling anyway as you're expecting to stop.
If a signal reverts on you, I.e. you see it change more restrictive then you'd put the train straight into emergency, or draw upto the signal if you've got time and speak to the signaller and fill out RT3185 for the train nerds.
If you pass the red then it'll put the brakes on for you assuming you havent already and it's fitted with a system called TPWS.
Chasing aspects, where the train behind is constantly seeing yellows is poor driving and is generally avoided. If you pass a single yellow you're generally crawling anyway as you're expecting to stop.
If a signal reverts on you, I.e. you see it change more restrictive then you'd put the train straight into emergency, or draw upto the signal if you've got time and speak to the signaller and fill out RT3185 for the train nerds.
If you pass the red then it'll put the brakes on for you assuming you havent already and it's fitted with a system called TPWS.
Edited by ChocolateFrog on Tuesday 2nd August 20:59
Thankfully safety is a priority and most of the time the general public are given safe travel.
Even a change of Aspect is a reportable event potentially with several hours of work if something is unexplained.
Everything from forward facing CCTV, Driver statements, a multitude of Signal testing and a whole load of paperwork to go along with it. Of course if something is considered to be even slightly amiss Medical screening would be implemented too taking more valuable time manpower resource.
Even a change of Aspect is a reportable event potentially with several hours of work if something is unexplained.
Everything from forward facing CCTV, Driver statements, a multitude of Signal testing and a whole load of paperwork to go along with it. Of course if something is considered to be even slightly amiss Medical screening would be implemented too taking more valuable time manpower resource.
ChocolateFrog said:
If you pass the red then it'll put the brakes on for you assuming you havent already and it's fitted with a system called TPWS.
I'm no expert on TPWS but it's generally only fitted on approach to converging Junctions or terminating routes like a bay platform.The arm and trigger sensors are fitted with sufficient distance to bring the train to a stand BEFORE passing the Red signal.
Rick101 said:
ChocolateFrog said:
If you pass the red then it'll put the brakes on for you assuming you havent already and it's fitted with a system called TPWS.
I'm no expert on TPWS but it's generally only fitted on approach to converging Junctions or terminating routes like a bay platform.The arm and trigger sensors are fitted with sufficient distance to bring the train to a stand BEFORE passing the Red signal.
Some signals have none, some have one or the other, some have both.
Both have arming and trigger loops but on approach they're spaced apart to measure speed (Over Speed Sensors) and will trip if you exceed a pre-determined speed. If they're placed together right next to the signal and are live when the signal is red then theyre TSS (Train Stop System) and will stop the train regardless of speed.
The higher risk the signal the more mitigating measures that are in place.
A colleague I trained with recently tripped an OSS, by around 5 mph. The subsequent investigation took 7 weeks to conclude before he could drive again with a development plan in hand. Do it again and he'll almost certainly be sacked, it's taken rather seriously.
Thanks folks. All rather undramatic then.
As a result of this and the delay at Peterborough while they decided what to with the Person who had collapsed (eventually offloaded to wait for the ambulance on the platform) we were about 20 minutes late.
You could tell the driver was on a catch-up mission with faster acceleration and late harder braking than normal. That Azuma really did move well.
As a result of this and the delay at Peterborough while they decided what to with the Person who had collapsed (eventually offloaded to wait for the ambulance on the platform) we were about 20 minutes late.
You could tell the driver was on a catch-up mission with faster acceleration and late harder braking than normal. That Azuma really did move well.
Simpo Two said:
anonymous said:
[redacted]
I'm generally with you, but what did the guard add to this situation, unless they had first aid skills?But to be honest on the inter-city trains there will always be staff available. Commuter services is where that discussion rests.
Rick101 said:
I'm no expert on TPWS but it's generally only fitted on approach to converging Junctions or terminating routes like a bay platform.
The arm and trigger sensors are fitted with sufficient distance to bring the train to a stand BEFORE passing the Red signal.
Erm no clearly not The arm and trigger sensors are fitted with sufficient distance to bring the train to a stand BEFORE passing the Red signal.
It’s not designed to prevent a SPAD but to mitigate against the consequences of a SPAD by stopping a train within the overlap of the signal before the risk of a conflicting move. It WILL NOT prevent a SPAD if a train is traveling fast enough over the over speed sensors that it leaves it with insufficient room to stop before the signal, but should bring it to a halt before there is a risk of a collision.You are correct when you state that it’s fitted on approach to converging junctions and bay platforms, but it’s also fitted to some permanent speed restrictions for example when there’s a large drop in speed (a reduction by a third from a line speed over 60mph from memory) and at some locations where there is a risk a SPAD could cause a conflicting movement within the overlap of the next stop signal.
Going back to egress alarms, it’s not a case of resetting it and going. You need to be sure nobody has actually left the train, which if they have opens up a whole new bloody minefield of getting blocks and getting the line examined.
demic said:
Going back to egress alarms, it’s not a case of resetting it and going. You need to be sure nobody has actually left the train, which if they have opens up a whole new bloody minefield of getting blocks and getting the line examined.
She was quite happy when she found the person who had pulled it - I don't think it actually opened as he was back in his coach before we stopped. While she thought someone had jumped out, it was clear that it would have been quite a problem!Simpo Two said:
anonymous said:
[redacted]
I'm generally with you, but what did the guard add to this situation, unless they had first aid skills?In a very busy area, as most of our main lines are, the difference between what I've described above and a situation where a lone driver has to wade back through potentially up to 12 coaches, after having first had a conversation with the signalman, and then sort out whatever's going on before walking back again, having another conversation with the signalman and perhaps also control, and then finally getting his train moving again, can be massive!
The delays, both to the train involved and many more around it, resulting from something that can often take seconds to actually physically resolve, can be eye watering. And extremely expensive!
Edited by anonymous-user on Thursday 4th August 13:33
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