Station overrun procedure

[BR Boy 125]

Why is it that the emergency brake is used if a train is in danger of overrunning a station platform? In my opinion it should be a full service brake application as there is no risk to safety of the line.

Well obviously trains are on a schedule therefore it would require maybe a 30 second delay which is not the best as most trains are tight (obviously again) so they need to be as accurate as possible, the emergency brake is necessary as the emergency brake is 1-5% more effective than full service.

 

[cjp]

Well obviously trains are on a schedule therefore it would require maybe a 30 second delay which is not the best as most trains are tight (obviously again) so they need to be as accurate as possible, the emergency brake is necessary as the emergency brake is 1-5% more effective than full service.

Generally what is the difference between Full Service and Emergency braking? And typically on say a ten carriage train what might be the difference in stopping from say 50mph or 100mph?
Thanks.

 

[bionic]

There's actually a contrary hazard here - treating overruns less stringently than SPADs might lead the driver adopting a different braking technique for station stops where the platform starter is off (or there isn't one) and thereby help to reinforce the significance of the platform starter being on.

I'm not sure what you are getting at here. If a station starting signal is on the driver would always use a different braking technique to if the starter was off or there wasn't one. You wouldn't come haring into a platform from line speed using your normal braking point if the starter was on.

 

[edwin_m]

I'm not sure what you are getting at here. If a station starting signal is on the driver would always use a different braking technique to if the starter was off or there wasn't one. You wouldn't come haring into a platform from line speed using your normal braking point if the starter was on.

Indeed. But if overruns are considered to have the same severity as SPADs then drivers will approach them in the same way, so all station approaches might end up being made equally cautiously. Applying a more cautious approach when the caution aspects indicate the platform starter is at danger is a way of remembering and reinforcing that this is not a routine stop.

 

[bionic]

Indeed. But if overruns are considered to have the same severity as SPADs then drivers will approach them in the same way, so all station approaches might end up being made equally cautiously. Applying a more cautious approach when the caution aspects indicate the platform starter is at danger is a way of remembering and reinforcing that this is not a routine stop.

You'd have to rewrite the entire timetable. Every train would be crawling. Suburban metro routes with lots of calls, especially, would be crippled. It's unnecessary, unrealistic and never going to happen.

Overrunning a station or failing to call is nowhere as serious as a SPAD and should not be treated the same. If you misjudge your braking and miss a station nobody is getting hurt. Worst case scenario people get a bit inconvenienced and the driver gets called in for a slap on the wrist. Its serious and could have career-limiting implications for the driver but its not in the same league as SPADS. With a SPAD we are talking about potential fatalities and serious infrastructure damage.

 

[edwin_m]

You'd have to rewrite the entire timetable. Every train would be crawling. Suburban metro routes with lots of calls, especially, would be crippled. It's unnecessary, unrealistic and never going to happen.

Overrunning a station or failing to call is nowhere as serious as a SPAD and should not be treated the same. If you misjudge your braking and miss a station nobody is getting hurt. Worst case scenario people get a bit inconvenienced and the driver gets called in for a slap on the wrist. Its serious and could have career-limiting implications for the driver but its not in the same league as SPADS. With a SPAD we are talking about potential fatalities and serious infrastructure damage.

I agree, and that's the point I was trying to make.

 

[bionic]

I agree, and that's the point I was trying to make.

My apologies, I read it that you were saying the two things should be treated equally.

 

[Llama]

Generally what is the difference between Full Service and Emergency braking? And typically on say a ten carriage train what might be the difference in stopping from say 50mph or 100mph?
Thanks.

Depends totally on the traction type - how long is a piece of string. Some traction has enhanced braking when emergency is selected, some traction doesn't. Emergency braking however should ensure that the brake is proven to be working to 100% of its capability and as quickly as is physically possible. That is not something that is necessarily the case with a service brake application.

 

[Journeyman]

Once again, I'd like to point out that this thread has been started by someone who has a hostile and paranoid attitude to authority, security and safety, and sharing internal railway procedures and processes with him is not a good idea.

 

[cjp]

Depends totally on the traction type - how long is a piece of string. Some traction has enhanced braking when emergency is selected, some traction doesn't. Emergency braking however should ensure that the brake is proven to be working to 100% of its capability and as quickly as is physically possible. That is not something that is necessarily the case with a service brake application.

Ok I was just thinking that on the old Heathrow Connect trains the platform braking was really smooth and did not end with a bit of a jerk whereas on a Tfl train the normal braking seems a lot more robust and I just wondered how bad it would be, as a passenger, if an emergency brake application was made. I had visions of standing passengers falling about like nine pins.

 

[Llama]

If procedural requirements are that the emergency brake is to be used then how smoothly a stop is made isn't a consideration.

 

[sw1ller]

All M Potter needs to know is, it’s the drivers licence, if s/he doesn’t put it in emergency, they’re putting their licence at risk. How much risk depends on their management and previous track record.

 

[sw1ller]

Indeed. But if overruns are considered to have the same severity as SPADs then drivers will approach them in the same way, so all station approaches might end up being made equally cautiously. Applying a more cautious approach when the caution aspects indicate the platform starter is at danger is a way of remembering and reinforcing that this is not a routine stop.

This is dangerous and in my opinion, is why there are so many SPADS. You don’t treat the station as a caution as starting up again becomes routine. If you approach the station differently when the signal is at danger, you’re more likely to remember that the signal is at danger when you’ve been told to go!

 

[cjp]

If procedural requirements are that the emergency brake is to be used then how smoothly a stop is made isn't a consideration.

Whilst I agree if it has to be done it has to be done but if it is a response to my question the response is an an arrogant one uncaring of the passengers and not indicative of how abrupt or effective such an application might be.

 

[edwin_m]

This is dangerous and in my opinion, is why there are so many SPADS. You don’t treat the station as a caution as starting up again becomes routine. If you approach the station differently when the signal is at danger, you’re more likely to remember that the signal is at danger when you’ve been told to go!

Again, that's the point I'm trying to make.

 

[sw1ller]

Again, that's the point I'm trying to make.

Ahh, I’m not at all with it today, very under the weather. Couldn’t quite get my head round that. Apologies.

 

[hexagon789]

Generally what is the difference between Full Service and Emergency braking?

Depends on the stock. For something like an HST or a 225, it's the same average deceleration - 9%g but the brake pipe vents more rapidly.

For a tread braked DMU with Westcode 3-step brake, such as a 156, the deleration rate is 7%g for both but Emergency is fail safe earthing the brake wires.

For a more modern DMU/EMUs (BR retrofitted some (321s I think), emergency provides a greater braking effort - in a 170 it gives 12%g against 9%g for Full Service.

That's my basic understanding of it.

 

[whhistle]

It's a shame with threads like this.

Someone has an opinion, others feel the need to give a stupid answer of explaining why it's like that.
Giving silly reasonings like "it's a safety risk" isn't really going to help anyone. Do you really think the OP will just say "oh okay" and end of thread?
You might as well say "because that's what's written in the rule book" or something else just as useless.

It's almost like someone can't challenge anything that's in the rule book (because of misunderstanding) becuse those that follow it without question at all (robots?), seem to think everyone else should be the same.

 

[Val3ntine]

Once again, I'd like to point out that this thread has been started by someone who has a hostile and paranoid attitude to authority, security and safety, and sharing internal railway procedures and processes with him is not a good idea.

I agree. I notice he always brings up random railway proceedures like this, sparks a massive debate and seems to just disappear as people try to answer his “concerns”.
Maybe we should stop fueling this strange habit with responses as it does no good. Most of the stuff he asks are usually a simple “Why is a railway proceedure like this when it shouldn’t be”
Simple answer should just be “Because it is” with no explantion needed or given.

 

[cjp]

It's a shame with threads like this.

Someone has an opinion, others feel the need to give a stupid answer of explaining why it's like that.
Giving silly reasonings like "it's a safety risk" isn't really going to help anyone. Do you really think the OP will just say "oh okay" and end of thread?
You might as well say "because that's what's written in the rule book" or something else just as useless.

It's almost like someone can't challenge anything that's in the rule book (because of misunderstanding) becuse those that follow it without question at all (robots?), seem to think everyone else should be the same.

Indeed.
I find many threads to be both interesting and informative but there are those who contribution amounts to "because it is" or " it's always been done like that".
When I was growing up a useful adage was if you cannot say anything nice bite your tongue and say nothing

 

[ComUtoR]

You might as well say "because that's what's written in the rule book" or something else just as useless.

Which is a valid answer. There are rules that dictate how thing are done. There is a difference between saying why is something done and why is that the rule.

It's almost like someone can't challenge anything that's in the rule book (because of misunderstanding) becuse those that follow it without question at all (robots?), seem to think everyone else should be the same.

The rulebook is challenged all the time and changes twice a year and more. It is followed strictly and to the letter because that is the requirement and can land you in jail when you don't follow it. Are you suggesting that the rulebook is more of a choice and that we should ignore it because we think something should be different?

I'm kinda confused why you suggest that people who follow the rules are robots. Personally I find that insulting and ignorant. The rules are there to protect the railway and generally does a very very good job at it. It provides a standard for everyone and provides a consistent approach across the entire network. It is frustrating for us and there are many times where you just want to do it a quicker or more efficient way. Its not that we don't want to. We can't.

The people who set the rules have lots of evidence about the effects and the reasons why they get implemented. Feel free to check the plethora of RAIB reports where rules get broken, stretched or downright ignored.

 

[Need2]

Well obviously trains are on a schedule therefore it would require maybe a 30 second delay which is not the best as most trains are tight (obviously again) so they need to be as accurate as possible, the emergency brake is necessary as the emergency brake is 1-5% more effective than full service.

1-5% more effective, really? At those figures it's not worth having an emergency brake!
On my traction course I was told it was approximately 30% more effective. (on 375)

 

[Need2]

I'm kinda confused why you suggest that people who follow the rules are robots. Personally I find that insulting and ignorant. The rules are there to protect the railway and generally does a very very good job at it. It provides a standard for everyone and provides a consistent approach across the entire network. It is frustrating for us and there are many times where you just want to do it a quicker or more efficient way. Its not that we don't want to. We can't.

The people who set the rules have lots of evidence about the effects and the reasons why they get implemented. Feel free to check the plethora of RAIB reports where rules get broken, stretched or downright ignored.

Well said!

 

[Val3ntine]

Indeed.
I find many threads to be both interesting and informative but there are those who contribution amounts to "because it is" or " it's always been done like that".
When I was growing up a useful adage was if you cannot say anything nice bite your tongue and say nothing

The problem is a lot of these posts are not asking why is a proceedure like this. It is stating that a proceedure should not be like this and that is their opinion which no reply will change for them.
Short of saying “Yes you are right we will from now refuse to follow the set proceedures, we shall go against it and fight until it is changed thank you for bringing it to attention”, there’s nothing less some on here will accept.

It’s cool to be curious and want to have a more thorough understanding about something but when it’s done in a way that you have made your mind up already and you want your view heard and heard until everyone agrees with you then yes it could become a bit hostile especially with staff who work to the set proceedures. Not saying you personally but in general.

For example plenty of people have answered the OP’s question and stated that emergency brake can give the train more of a chance to stop rather than just a full service application. I mean is that not enough of an answer?
Some have even gone above and beyond and explained proceedures get more complicated in regards to how far a station can be overran in order to set back into the station, if there’s level crossings within that vicinity that then changes things even further, and the type of level crossing it is too. So the best chance you have of stopping the train as soon as possible even if still overrunning the station you take it, and that means using the emergency brake as that gives you the best chance.

You could argue well why bother, just skip the station it’s more hassle than it’s worth, they don’t seem to care about passenger comfort suggesting using the emergency brake (I don’t think I recall ever hearing of any passenger injury due to the use of an emergency brake application in history, someone do correct me if i’m wrong though).
So skip that station to avoid using emergency brake and salvage passenger comfort. Cool. How long before the next train? Not every train runs suburban 15-30 minute frequencies. It could be a 2 hour wait for the relevant next train or even more. It could be a whole day wait for the next relevant train. It could be the last train of the day.
Here you are now at the danger of introducing different rules to different trains. If you know there is a large wait for the next train use the emergency brake to attempt to stop at this station, if not then don’t bother. One station could be a long wait, the very next station could only be a 5 min wait for the next train. Or even if it’s suburban territory with no more than 30 min waits between all trains, how does the driver know what’s happened behind him/her that there’s now not an unusually long wait if he does not attempt to try and call at that station. What if he’s/she’s the second to last train of the day, is about to overshoot and decides against using the emergency brake to stop because there will be another behind. How does he/she know it’s not been cancelled for whatever reason.

Or better yet, all drivers follow the proceedure that’s in place and use the emergency brake if neccesary if they feel they will not be able to stop in time?!

 

[Llama]

The impact of the subsequent potential cancellations on customer comfort should also be taken into account if the driver is removed from duties to have tea without biscuits upstairs, because they perhaps didn't follow regulations that are often hammered home, in so far as they didn't apply the emergency brake when they no longer had full control of the train attempting to stop, and that driver is then unable to work the rest of their diagram.

 

[edwin_m]

Depends on the stock. For something like an HST or a 225, it's the same average deceleration - 9%g but the brake pipe vents more rapidly.

For a tread braked DMU with Westcode 3-step brake, such as a 156, the deleration rate is 7%g for both but Emergency is fail safe earthing the brake wires.

For a more modern DMU/EMUs (BR retrofitted some (321s I think), emergency provides a greater braking effort - in a 170 it gives 12%g against 9%g for Full Service.

That's my basic understanding of it.

I was on a BR/Railtrack committee on SPAD reduction and mitigation circa 1994 and one of the measures adopted was to increase the emergency brake rate to 12%g for future stock, and for current stock where feasible. This was to give the drivers something extra in an emergency, while not making it available in normal circumstances otherwise its use would just become routine (and when adhesion is poor it wouldn't be achievable anyway, at least until sanders came in a few years later).

Well obviously trains are on a schedule therefore it would require maybe a 30 second delay which is not the best as most trains are tight (obviously again) so they need to be as accurate as possible, the emergency brake is necessary as the emergency brake is 1-5% more effective than full service.

1-5% more effective, really? At those figures it's not worth having an emergency brake!
On my traction course I was told it was approximately 30% more effective. (on 375)

I think you may be at cross purposes here. The emergency brake may give an extra deceleration of between 1% and 5% of gravity (between 1m/s2 and 5m/s2) but it increases the available deceleration by much more, going from 9m/s2 to 12m/s2 giving 33% in the example above. The stopping distance reduces by the same ratio as the deceleration increases.

 

[Need2]

I think you may be at cross purposes here. The emergency brake may give an extra deceleration of between 1% and 5% of gravity (between 1m/s2 and 5m/s2) but it increases the available deceleration by much more, going from 9m/s2 to 12m/s2 giving 33% in the example above. The stopping distance reduces by the same ratio as the deceleration increases.

I love it when people obviously know what they are talking about, thanks for the correction.

 

[cjp]

The problem is a lot of these posts are not asking why is a proceedure like this. It is stating that a proceedure should not be like this and that is their opinion which no reply will change for them.
Short of saying “Yes you are right we will from now refuse to follow the set proceedures, we shall go against it and fight until it is changed thank you for bringing it to attention”, there’s nothing less some on here will accept.

Or better yet, all drivers follow the proceedure that’s in place and use the emergency brake if neccesary if they feel they will not be able to stop in time?!
....

Thank you for taking the time to write all this.

Think I have only ever once experienced what I thought was an emergency brake application and we still slightly overran. When the doors opened - it was the Wimbledon branch and I was a teenager- I just jumped down onto the bottom of the ramp and went up onto the platform and out. These things happens; no big deal as far as I was concerned at the time.
....

 

[whhistle]

Which is a valid answer. There are rules that dictate how thing are done. There is a difference between saying why is something done and why is that the rule.

*sigh*
You miss the point and have missed what I wrote.

Someone asks a question that obviously doesn't understand why something is like it is.
How is saying "because that's what's written" going to help this person understand the reasoning behind it, and thus understand why the rule is like it is?

Someone who blindly follows rules because they're told to, in my opinion, isn't a healthy way to go about life.
Have you read about Milgram's Study of Obedience?
Yes, shooting people or shocking them until they're dead is fairly different to following the Rule Book, but the mechanic is the same - following something that you've been told, no questions asked... ever.

A lot of what is written in the Rule Book should be followed (most is common sense!). But the self-admitting fact it changes twice a year shows that it's not correct to follow everything if you don't understand why you're following it.

Are you suggesting that the rulebook is more of a choice and that we should ignore it because we think something should be different?

No, I'm not suggesting that.
And you should try and learn to stop putting words in peoples mouths
That's like me saying "are you suggesting anyone who follows the rule book would also shoot someone if they were told to?" No. I'm sure you're not.

There's a big difference between following something that you understand through and through, and thinking it is a choice.

EG: If a signalman and line controller told a driver to carry on at line speed, even if you as a driver knew there was a large obstruction in the way, would you carry on? Because you've been told to, even though you know it means the end of life for some people.

If you blindly follow rules, without question, simply being a robot, doing what you're told, no matter what it is... it's just not right.
Most of the time what's being asked is agreeable, which is why there is no problem, but to suggest Train Drivers should follow rules, come what may is just plain wrong, in my opinion of cuose.

 

[whhistle]

The problem is a lot of these posts are not asking why is a proceedure like this. It is stating that a proceedure should not be like this and that is their opinion which no reply will change for them.

Helping someone understand why it's like that can change their mind though.
That's why there's so much confusion about Brexit. Half the people don't know why we can't just leave, pay no more money and trade with whomever we see fit. The other half seem to think we'll be starved of food if we left, but the UK Government/media/whoever doesn't ever say why we can't just do this or that.
Damn. Brexit really is everywhere!