LeylandLen
Member
Trains being cancelled at Preston and Warrington as a result of another sad incident near Wigan NW .such as : 1M07 This service was cancelled between Preston and London Euston due to a person hit by a train
Holding on. An emergency brake application still takes a few miles to stop a train.Can anything be done to ensure passenger safety in these situations?

I've been on a Class 350 (the same type as involved in this morning's incident) as a standing passenger during an emergency brake application, albeit due to a passenger alarm activation rather than anything more serious. I can confirm that I, and my fellow standees, remained vertical at all times![]()
It does worry me when I read of these services that possibly have standing passengers at the time of an emergency breaking situation. The risks of injury are too terrible to consider, if people are standing, unsupported by anything, and the train suddenly lurches to a halt, especially if the train was doing top speed at the time. Can anything be done to ensure passenger safety in these situations?
Holding on. An emergency brake application still takes a few miles to stop a train.
I doubt there is any passenger train operating in the UK that would take a "few miles" to come to a stand under emergency braking even from top speed
I believe the requirement is for any train to be able to stop in 1.25 miles.Prior to introduction into service of the HST a high-speed braking trial was carried out to prove that it could stop from 125mph in no more distance than the current trains needed to stop from 100mph. I remember very clearly the distance achieved as being "one mile and one carriage length".
Holding on. An emergency brake application still takes a few miles to stop a train.
Holding on. An emergency brake application still takes a few miles to stop a train.
I doubt there is any passenger train operating in the UK that would take a "few miles" to come to a stand under emergency braking even from top speed
"one mile and one carriage length".
It's clearly well over a mile, so "a few miles" isn't a gross exaggeration. We have been told many times that a train can't possibly stop within sighting distance, hence single and double yellow signal aspects. Given that there only seem to be about 2 signal sections visible southwards from Crewe nowadays, I would think that it must allow about 5 miles from a green to a red.I believe the requirement is for any train to be able to stop in 1.25 miles.
is irrelevant as there are 3 or 4 sections warning!I hope not, we don't give them that long to stop between signals, and that's with a 'normal' brake application.
Thanks @tsr for a genuinely useful and interesting post. I've learned something thereThe existence of yellow and double yellow signal aspects can also vary with the length of a signal section - if a yellow signal is displayed to a train travelling at (say) 80mph, the driver will simply need enough space to react and slow down before the red. There are some pretty high linespeeds on three-aspect signalling.
But if this is not possible, a double yellow signal needs to warn the driver of the cautionary yellow aspect further down, so that the driver is expecting this. There are places around the country where four-aspect signalling with double yellows is specifically provided due to allow drivers to be warned of the need to stop within a shorter distance than usual, for example if the distance between the two subsequent signals would not allow the train to reduce speed from the maximum permitted upon seeing a single yellow, in time for a red. There are also places where there is only the warning of a yellow aspect and sufficient stopping distance is accordingly provided.
In all cases, signal section length may also end up exceeding the distance ever realistically needed to slow to a stop, so there are plenty of lines where the distance would vary. Sometimes a driver may not actually need to brake until some time after a single yellow is displayed. They may even need to stop at a station and then proceed towards a red signal which is still some way away. This often occurs where signalling has been "rationalised" and there is no longer a station platform starter signal, but a distant signal now warns of a danger signal some way beyond the station. Anyway, that's a bit off-topic!
We can then boil this down further to two-aspect running, which can effectively be on line-of-sight in some cases. Linespeeds would reflect this, and are unlikely to be practical for intercity services running at higher speeds.
Emergency braking should not be routine and is designed to stop the train as quickly as possible in out-of-course situations where the driver has to react to something in their field of vision - or if the driver may be unresponsive and could not respond to signals or events occurring in front of them. The original topic of conversation regarding emergency braking is not about stopping in time for normal signal aspects, and in fact emergency braking should not normal be used to stop at signals in routine running. In this case, the designed overall distance of (say) a few miles between green and red signals would be irrelevant.
In the event of a train accident (the definition of which, according to the RSSB Rule Book, includes a person hit by a train), the train crew would be expecting a train to need at least a mile and a quarter to stop - when protecting the line in a worst-case scenario, you place detonators at a mile and a quarter from the accident, and then you may need to continue until you find help or can call for help, being prepared to stop oncoming trains.

A little off topic, but apparently all lines blocked for the time being to/from London Euston, owing to a suicidal person threatening to jump from an over bridge (not sure precisely where). I believe the power supply to the overheads has been turned off for the time being.
Thanks @tsr for a genuinely useful and interesting post. I've learned something there![]()

It does worry me when I read of these services that possibly have standing passengers at the time of an emergency breaking situation. The risks of injury are too terrible to consider, if people are standing, unsupported by anything, and the train suddenly lurches to a halt, especially if the train was doing top speed at the time. Can anything be done to ensure passenger safety in these situations?
Is there any correlation between the frequency of suicide attempts on the railway and the current weather conditions? I'm curious because the Met Office are predicting large parts of the country will experience zero sunshine from today for a full week at least, accompanied by rain. The near-continuous twilight-like light levels can't do much for well-being, especially if someone is already feeling low.
if that held any water those of us from the north east would be in trouble. It's called winter in the rest of the country and everyday for us!
No it isn't. NE England receives over 1300 hours of sunshine per year averaged over 1981-2010. NE Scotland is a little bit lower, but only much lower in the Grampian mountains. To claim zero sunshine is an everyday occurence is absurd.
It would not surprise me if day after day after day of gloom and poor light levels would amplify the effects of depression if it coincided with another tragic event in a persons life. I can appreciate that government policies over recent years and the consequences could be a major factor. I am just curious if some of the inter-annual variability in depression and suicide rates could be explained by the weather. I vaguely remember hearing that suicide rates in the Scandinavian countries are highest in the winter, where winter daylight is a lot lower than here.