Croydon Tram Accident

[Re6/6]

http://www.bbc.co.uk/news/uk-england-38003934

[Talltim]

Seems extraordinary that there were no mechanical aids/signalling to ensure that trams were travelling at a suitably slow pace at such a difficult location.

There's a speed limit, same as on thousands of roads. And there's there's all the roads that don't have specific speed limits for corners...

[phil-b259]

A 50 mph stretch of tramway leads into a 12 mph speed restriction.

 

The equivalent of that on a 125 mph mainline railway would be a requirement to slow to 25 mph.

 

Are there any places on the main line where that scenario exists, without some form of approach control.

 

If indeed that is the recommendation that now results, could that be achieved affordably and within the laws of physics, given the very short distance braking requirements for light rail.

 

I was thinking something using GPS or track side transducers, similar to the those used on the WCML.

 

The point is that the Trams themselves DON'T have any self acting speed control or SPAD prevention device fitted like trains do. As such you can fit all the gizmos you like to the track but to make them useful you will need to do some extensive modification work to the Tram fleet - which won't be cheap.

 

Thats not to say that in the medium term its not possible to fit some form of over speed sensor and intervention kit to the Tram fleet - but its not something you can do immediately. As such other more basic methods such as 'those speed activated signs found on roads, improved lighting on the approch or a 'Stop' then proceed style board being erected on the approch are much easier to implement in the short term.

 

In any case, given the severity of the incident and its consequences, when trams services resume through Sandlands, I bet all drivers will be ultra cautious anyway - as such a tragic incident will live on in their minds for years to come

Edited November 16, 2016 by phil-b259

[D854_Tiger]

The point is that the Trams themselves DON'T have any self acting speed control or SPAD prevention device fitted like trains do. As such you can fit all the gizmos you like to the track but to make them useful you will need to do some extensive modification work to the Tram fleet - which won't be cheap.

 

Thats not to say that in the medium term its not possible to fit some form of over speed sensor and intervention kit to the Tram fleet - but its not something you can do immediately. As such other more basic methods such as 'those speed activated signs found on roads, improved lighting on the approch or a 'Stop' then proceed style board being erected on the approch are much easier to implement in the short term.

 

In any case, given the severity of the incident and its consequences, when trams services resume through Sandlands, I bet all drivers will be ultra cautious anyway - as such a tragic incident will live on in their minds for years to come

 

 

A similar main line scenario was the curve at Morpeth on the ECML.

 

In recent years, there had been three serious accidents on that curve before an AWS alert was implemented.

[jamie92208]

A similar main line scenario was the curve at Morpeth on the ECML.

 

In recent years, there had been three serious accidents on that curve before an AWS alert was implemented.

From recent experience riding Nottingham and Metrolink there are a lot of similar situations on those systems, coincidentally some of them are at points where the trams leave a former railway route to go street running.

 

 

Jamie

Edited November 16, 2016 by jamie92208

[martin_wynne]

[Mallard60022]

Slightly OT but is The Docklands LR Driverless? If so, what are the automatic systems for speed control? The reason I ask is that, as some have already hinted at, some sort of mechanical or electrical override/intervention despite what the driver might be doing (or not doing if they are unable in some way),  would appear to be required at this location and best practice examples are seemingly available. Tragic incidents like this are very sad indeed and it will be interesting to see what measures are introduced.

Phil 

[47137]

The headline on the BBC at the moment is,

Croydon tram crash: Driver was 'three times over speed limit'

 

We know the event behind this topic was a crash, but we don't know whether it was an accident. Therefore could the OP or the moderators consider amending the topic title from "Croydon Tram Accident" to something less judgemental.

 

- Richard.

Edited November 16, 2016 by 47137

[Talltim]

Surely saying it was an accident is less judgemental than saying it wasn't an accident?

[Titan]

The headline on the BBC at the moment is,

Croydon tram crash: Driver was 'three times over speed limit'

 

We know the event behind this topic was a crash, but we don't know whether it was an accident. Therefore could the OP or the moderators consider amending the topic title from "Croydon Tram Accident" to something less judgemental.

 

- Richard.

 

I think you will find 'Accident' is the generic term for this type of event, be it accidental or not. Because of this not using the generic term is judgemental, as it it implies that it might not be an accident!

[Oldddudders]

I applaud the invitations to the public to report any other instances of excessive speed/discomfort in that locale. But I hope that someone also calculates how many trams have made that tight turn securely since the system opened. By all means make it safer - but keep a sense of proportion in investing, if it simply turns out to be human error. 

[The Stationmaster]

Surely saying it was an accident is less judgemental than saying it wasn't an accident?

 

In reality the primary incident (overspeed apart) was a derailment and I would refer to it as such.  That is descriptive without any sort of pejorative or judgemental inference although clearly indicates that something happened which should not have happened.  

 

From a professional viewpoint I have never liked the term 'accident' as it implies that whatever it was that happened could well have been unavoidable and in almost all cases investigation has proved that what happened would have been avoided if everybody had followed the correct procedures.  The word 'crash' is of course much liked by the media - it's a nice short and 'harsh' word for the printed media and sufficiently emotive for the broadcast media while in many cases often actually being at least generally descriptive of what eventually happened in the incident - as in this case where following its derailment the tram crashed to the ground.

 

But 'accident' - no, it's sloppy reportage and usually misleading.

[D854_Tiger]

In reality the primary incident (overspeed apart) was a derailment and I would refer to it as such.  That is descriptive without any sort of pejorative or judgemental inference although clearly indicates that something happened which should not have happened.  

 

From a professional viewpoint I have never liked the term 'accident' as it implies that whatever it was that happened could well have been unavoidable and in almost all cases investigation has proved that what happened would have been avoided if everybody had followed the correct procedures.  The word 'crash' is of course much liked by the media - it's a nice short and 'harsh' word for the printed media and sufficiently emotive for the broadcast media while in many cases often actually being at least generally descriptive of what eventually happened in the incident - as in this case where following its derailment the tram crashed to the ground.

 

But 'accident' - no, it's sloppy reportage and usually misleading.

 

 

They're reporting that the driver was three times over the speed limit, not the tram, that only implies one thing and are we sure the BBC is correct in saying so.

[Reorte]

 

From a professional viewpoint I have never liked the term 'accident' as it implies that whatever it was that happened could well have been unavoidable

Something could easily have been avoidable yet still accidental. It's only not an accident if someone intended this to happen. All the word "accident" means is "not deliberate", not "not avoidable." Although sadly unpleasant things do occasionally happen due to deliberate behaviour I generally view the word "accident" as a fairly neutral and generic term (at least until more information is available).

Edited November 16, 2016 by Reorte

[47137]

I think you will find 'Accident' is the generic term for this type of event, be it accidental or not. Because of this not using the generic term is judgemental, as it it implies that it might not be an accident!

I take your point, and indeed the UK Government body which investigates incidents is called the Rail Accident Investigation Branch.

 

I am troubled about one particular possible root cause, and this made me look up 'accident' in a dictionary.

 

- Richard.

[leopardml2341]

DLR is driverless and it uses a form of Automatic Train Operation, similar in principle to ERTMS which uses permission to move radio messages based on the known traffic in the vicinity.

 

Edit: this response refers to #296 above - I was distracted

Edited November 16, 2016 by leopardml2341

[grandadbob]

As the OP my original topic title was, if I recall correctly, "Croydon Tram Overturns". Another topic was started at almost the same time and the Mods merged the two and amended the title so if it needs changing then I will leave it to them to decide.

Edited November 16, 2016 by grandadbob

[Forester]

Hope the investigation looks to and learns from modern Aviation Safety.

 

Air safety remained stubbornly poor until investigators stopped automatically blaming the pilot and started looking at the systems which allowed, even encouraged, mistakes to be made. The effect on safety was immediately positive and lead to the very high air safety levels we benefit from today.

 

If a mistake Can be made, sooner or later it Will be made.

 

In this case that is a ridiculously tight curve for such a large tram in regular passenger-carrying service. Add a long straight stretch leading up to it and this was quite clearly an accident waiting to happen. Nor do I see the need for it looking at a plan of the track, although I've not been there.

 

Hope the investigation turns out to be a modern enlightened one.

[Metr0Land]

I applaud the invitations to the public to report any other instances of excessive speed/discomfort in that locale. But I hope that someone also calculates how many trams have made that tight turn securely since the system opened. By all means make it safer - but keep a sense of proportion in investing, if it simply turns out to be human error. 

 

Am I being blindingly stupid here?  We've had all kinds discussions on here as to what kind of systems exist on the tramway, and those which may be adapted from elsewhere, all of which seem to me to add cost and complexity.

 

If it's the case that the driver became incapacitated then many of them might get over-ridden (eg driver slumping on deadman's handle).

 

However, as I drive about my daily business I'm frequently passing speed signs on the road which light up as I approach.  The local one being in a 40mph zone where my speed is shown in green up to 40 and then in red from 41mph upwards.  Given that this location has 50mph leading onto 12mph surely a couple of these displays approaching the junction would cost a fraction of some systems, and should do the trick provided the driver is anything like alert?

[Bomag]

In reality the primary incident (overspeed apart) was a derailment and I would refer to it as such.  That is descriptive without any sort of pejorative or judgemental inference although clearly indicates that something happened which should not have happened.  

 

From a professional viewpoint I have never liked the term 'accident' as it implies that whatever it was that happened could well have been unavoidable and in almost all cases investigation has proved that what happened would have been avoided if everybody had followed the correct procedures.  The word 'crash' is of course much liked by the media - it's a nice short and 'harsh' word for the printed media and sufficiently emotive for the broadcast media while in many cases often actually being at least generally descriptive of what eventually happened in the incident - as in this case where following its derailment the tram crashed to the ground.

 

But 'accident' - no, it's sloppy reportage and usually misleading.

 

Slightly OT

 

I work with road accident data looking at improving safety via road design. The use of 'accident' does not imply that it was unavoidable, only it was not deliberate (which is common enough to need weeding out of stats) irrespective of how reckless the driver is. Having failed O level English three times and then giving up having got into Uni, I am the last person to criticise people's use of English; however, what does irritate me is those who say the use of the word 'accident' is pejorative or sloppy. No it is perfectly good word for the intended meaning.

 

There is a continuing low level conflict between signing accident and 'incident' on VMS. Not only is accident better understood by non-native English speakers but also leads to a greater and more consistent reduction in traffic speeds than the anodyne 'incident'. Currently the pink and fluffy brigade hold sway.

Edited November 16, 2016 by Bomag

[ruggedpeak]

Slightly OT

 

I work with road accident data looking at improving safety via road design. The use of 'accident' does not imply that it was unavoidable, only it was not deliberate (which is common enough to need weeding out of stats) irrespective of how reckless the driver is. Having failed O level English three times and then giving up having got into Uni, I am the last person to critice poeple's use of English; however, what does irritate me is those who say the use of the word 'acident' is perjorative or sloppy. No it is pefectly good word for the intended meaning.

 

There is a cotinuing low level conflict between signing accident and 'incident' on VMS. Not only is accident better understood by non-native English speakers but also leads to a greater and more consistent reduction in traffic speeds than the anodine 'incident'. Currently the pink and fluffy brigade hold sway.

The Police used to refer to crashes as Road Traffic Accidents, RTA's, but now refer to them as Road Traffic Collisions, to reflect the fact that over 90% of road crashes, deaths and injuries are the direct result of human error and poor driving (rather than mechanical failure), usually involving one or more Traffic offences and the fact that when things go wrong they generally involve a road vehicle colliding with something such as another road vehicle, object, pedestrian etc. They are are definitely collisions but rarely if ever are they accidental. Someone was almost inevitably doing something they shouldn't have. That does not mean it was pre-meditated, but it was a decision by a human to do something that was not a good idea. so not a random "accident". The phrase accident gives the very incorrect impression the collision was unavoidable. And the vast majority are entirely avoidable. I'm afraid the use of the word accident avoids blame for things that should have blame attributed to them.

 

There's a speed limit, same as on thousands of roads. And there's there's all the roads that don't have specific speed limits for corners...

Except that in many cases extensive measures other than speed limits are put in place to inform drivers of the corner, especially when there have been previous injury crashes - http://www.rmweb.co.uk/community/index.php?/topic/116642-croydon-tram-accident/page-10&do=findComment&comment=2497081

[ruggedpeak]

Am I being blindingly stupid here?  We've had all kinds discussions on here as to what kind of systems exist on the tramway, and those which may be adapted from elsewhere, all of which seem to me to add cost and complexity.

 

If it's the case that the driver became incapacitated then many of them might get over-ridden (eg driver slumping on deadman's handle).

It is not clear yet why the tram came to be travelling at nearly 4x the limit for the curve, but we do now know from media reports that this was not the first time a tram has gone round that bend at speeds that were apparently excessive. http://www.bbc.co.uk/news/uk-england-london-37979121

 

Indeed as many safety investigations conclude, there are often warnings of problems before the actual disaster strikes. That is why the HSE and others are so keen on near miss reporting.

[andyman7]

Hope the investigation looks to and learns from modern Aviation Safety.

 

Air safety remained stubbornly poor until investigators stopped automatically blaming the pilot and started looking at the systems which allowed, even encouraged, mistakes to be made. The effect on safety was immediately positive and lead to the very high air safety levels we benefit from today.

 

If a mistake Can be made, sooner or later it Will be made.

 

In this case that is a ridiculously tight curve for such a large tram in regular passenger-carrying service. Add a long straight stretch leading up to it and this was quite clearly an accident waiting to happen. Nor do I see the need for it looking at a plan of the track, although I've not been there.

 

Hope the investigation turns out to be a modern enlightened one.

I realise you've made this suggestion in good faith, but in fact the processes you refer to already exist much closer to home in rail safety. That has followed exactly the same trajectory, with a major sea change in the late 90s from merely identifying rule breaking to understanding why rules got broken. That is one of the reasons why (heavy) rail is so safe. The issue I think this will draw attention to is that trams are subject to a much less onerous regime - they are driven on sight in the manner of road vehicles. Traditionally of course trams were basically street running vehicles but modern trams often make use of old railway formations (which by their nature tend to be level and suited to fast running) and this incident will I believe highlight the need to pay more attention to the risks where fast running reserved sections interface with much slower sections.

[jjb1970]

Personally I don't like the idea of human error. I'm not saying that people don't make mistakes but the risk assessment process should consider the risks of severe reductions in speed limits and the potential for error and a modern safety critical system should be engineered to minimise the potential for human error to result in disaster. Yes, automatic protection systems move the potential for human error from the operator to those in design, manufacture and commissioning but those stages can be more closely controlled and subject to rigorous assurance processes. And then there are all the softer factors such as corporate cultures, training, oversight etc. Very few incidents happen because of a single failing, and if a single failure can cause an incident which results in multiple fatalities then that in itself is very worrying and should initiate some serious investigation. None of which is to remove responsibility of individuals for their actions, but there is more than human error in any major incident.

[Colin_McLeod]

The headline on the BBC at the moment is,

Croydon tram crash: Driver was 'three times over speed limit'

 

We know the event behind this topic was a crash, but we don't know whether it was an accident. Therefore could the OP or the moderators consider amending the topic title from "Croydon Tram Accident" to something less judgemental.

 

- Richard.

It was not a crash. It was a derailment. I see nothing wrong with the thread title and see no need to amend it Edited November 16, 2016 by Colin_McLeod