Croydon Tram Accident

[phil-b259]

No, they use the metric system, because seemingly its cheaper to buy in 'ready to roll' trams from Europe. You went on to say exactly that.

 

I think you will find there was a desire by the DfT back in the late 80s to ensure the signs used for first modern tramway in the UK for decades (Manchester) could not be mistaken for conventional road signs. Going for a metric speed limit was a useful in assisting with this.

Edited November 19, 2016 by phil-b259

[phil-b259]

Especially as these days a laser produced clear label, could be fitted over! Even in the far off days of dual marked speedometers in Australia, the thing was a printed disc, marked accordingly.

 

A plane fairly recently made a successful emergency landing (in Canada IIRC), where the plane had run out of fuel. The mistake occurred, because of confusion over imperial/metric volumes of fuel. I think it could be successfully argued that, airline pilots are significantly higher trained, than tram drivers operating on one system. No disrespect to tram drivers intended, just pointing out a perspective.

 

A reference for those, who think it is just a matter of training drivers/pilots to know the difference.

 

 

Like it or not Metric measurements are the official units for all science / engineering - we only keep imperial distances / speeds on the roads (and classic railways) of the UK because of the cost (and logistics) of changing it over. Brand new systems all over the world (other than the USA) have embraced the metric way with very few problems - HS2 will be an entirely metric railway too.

[david.hill64]

Just a few observations.

 

From the initial RAIB report we know that failure of the track or tram mechanical and electrical systems is unlikely to have contributed to the accident. Therefore it is probable that the investigation will focus on human error and the factors that contribute to this. Additionally we know that RAIB will investigate whether the tram's crashworthiness design is adequate. There have already been a number of comments in the general press about the tram design leading to so many fatalities in a relatively low speed event.

 

When we were working on the SPAD reduction and mitigation project in the early 90's, the team sought the advice of human factors experts to advise on some of the behavioural aspects and ergonomics. It struck me then that trying to understand why complex beings (ie us) do things in a certain way is a thankless task. We all have opinions that often are at variance with evidence but we will defend them to the end. We all make mistakes without intending to. It's human nature.

 

Doing repetitive tasks does give rise to risk. In the railway environment auto-cancelling the AWS warning when running on double yellows is an oft-cited example. In a different context how many people have experienced a safe regular drive and been unable to recall the specifics of part of the journey because you have been driving on autopilot? It's certainly happened to me.

 

Fatigue and the effect of shift patterns and the body's natural rhythm are better understood now, but not completely so. I am sure this issue will be examined for this event.

 

Trying to get to the root cause of this is going to be difficult or impossible but at least RAIB will be able to call on the opinions of recognised experts in the field.

 

The one issue that does worry me are the reports that taking this curve too fast may not have been an isolated event. It is said that when HST's were introduced there was a '140club' of drivers, complete with its own commemorative tie, for drivers who had achieved this magic figure. I have good reason to understand that this is not a fiction. Action was certainly taken to limit HST top speed. Was there something similarly stupid at Croydon? Extremely unlikely, but not impossible.

 

I am not suggesting that the tram driver consciously took an action that resulted as it did: just pointing out that I expect RAIB will want to exclude it. 

 

I also expect that RAIB will also want to exclude the possibility of confusion between imperial and metric units when people are using both through the day and there are no supervision systems in place to protect against errors. (Remember that speedos were a late addition to driving cabs - drivers could (and did) judge speed quite well without them. So was it the habit of Croydon drivers to follow the speedo or their judgement?).

 

This incident is going to be one of the hardest - or even the hardest - that RAIB has had to investigate to date.

[phil-b259]

 

I also expect that RAIB will also want to exclude the possibility of confusion between imperial and metric units when people are using both through the day and there are no supervision systems in place to protect against errors. (Remember that speedos were a late addition to driving cabs - drivers could (and did) judge speed quite well without them. So was it the habit of Croydon drivers to follow the speedo or their judgement?).

 

 

When a tram driver books on for a shift they enter a metric world - ALL tram applicable speed limits are separately signed from road ones and use kph. They will only need to revert to imperial measurements when they book off shift and start driving home.

 

Also the Croydon trams have had speedometers from day one - yes I know it was a fairly late thing to be fitted to steam locomotives, but there is no way modern tram systems would get away installing them.

[phil-b259]

This incident is going to be one of the hardest - or even the hardest - that RAIB has had to investigate to date.

 

Yes and no.

 

Yes because all the evidence points towards human failings which can vary from person to person, day to day etc. - no because of all the technical data available to them which quite clearly shows the tram was going to fast round the bend and the lack of any speed supervision systems in use.

Edited November 19, 2016 by phil-b259

[david.hill64]

Yes and no.

 

Yes because all the evidence points towards human failings which can vary from person to person, day to day etc. - no because of all the technical data available to them which quite clearly shows the tram was going to fast round the bend and the lack of any speed supervision systems in use.

Sorry should have been more specific. If we assume that it was human error, then understanding why that human error occurred is going to make it hard to determine a root cause or causes unless there is something obvious like fatigue, stress or medical condition. That's why I think it hard.

[david.hill64]

When a tram driver books on for a shift they enter a metric world - ALL tram applicable speed limits are separately signed from road ones and use kph. They will only need to revert to imperial measurements when they book off shift and start driving home.

 

Also the Croydon trams have had speedometers from day one - yes I know it was a fairly late thing to be fitted to steam locomotives, but there is no way modern tram systems would get away installing them.

I don't disagree with you: I just say I expect it will be considered. And as I remarked before, even if it were a factor, the overspeed was so great that it could not be an explanation.

Edited November 19, 2016 by david.hill64

[jjb1970]

I didn't suggest that the imperial - metric mix was a causal factor in this incident. I said that mixing imperial and metric introduces confusion and potential for error. Kevinmls has already noted the example of the Air Canada Gimli Glider, another famous example is the NASA Mars orbiter that failed because units were mixed. I've reviewed incidents where it was a factor.

Something that strikes me is the heavy focus on technical factors. Based on what I can see I think the key to unlocking what went wrong will be human factors and non-technical factors. And that is much more than driver error, I think there are worrying indications of deeper cultural and management issues.

[rockershovel]

I was doing some background reading, a while ago regarding trams in their heyday. It would seem that trams operated a system and culture quite different from the "big railway" and few, if any if their operating staff had a "big railway" background.

 

London Underground seem to be very much "big railway" in their practices and culture. What is the situation regarding modern trams?

[PenrithBeacon]

And people who drive boats and planes operate in knots and seem to cope.

They shouldn't be engaging in such extreme manoeuvres so as to tie their vehicle in knots!

[BlueLightning]

Just seen this pop up on the BBC news regarding the tram http://www.bbc.co.uk/news/uk-england-london-38036567

 

Does make me wonder whether it was reported previously and ignored. I doubt it very much but you never know

 

Gary

[edcayton]

People have asked why passengers didn't get the driver's attention. Am I correct in thinking that the driver sits behind glass in his/her own cubicle? In any case, this is stiff-upper lip Britain where we don't like to make a fuss. Seriously.

 

Secondly, why does this system have drivers at all? It was built well after the driverless DLR and some LUL lines where the driver is apparently only there to "reassure" the passengers.

 

Ed

[grahame]

 

Secondly, why does this system have drivers at all? It was built well after the driverless DLR and some LUL lines where the driver is apparently only there to "reassure" the passengers.

 

Ed

 

I don't know for sure but I'd guess that one of the issues making automation 'difficult' is that trams undertake street running where there is very much more chance of interaction with other road vehicles driven by unpredictable humans, unlike just knowing where all the other trams are on the tracks and the track layout. Hopefully a tram driver would spot an idiot parked on the road over the tracks up ahead or someone about to enter that area. Although, of course, we are now very close to seeing automatic driverless vehicles on our roads but that technology wasn't probably developed sufficiently when the trams system was built some years ago now.

 

G.

Edited November 19, 2016 by grahame

[ruggedpeak]

Just seen this pop up on the BBC news regarding the tram http://www.bbc.co.uk/news/uk-england-london-38036567

 

Does make me wonder whether it was reported previously and ignored. I doubt it very much but you never know

 

Gary

Seen that as well, and reinforces in my view of the potential for some systemic as well as individual causes contributing to the incident.

[ruggedpeak]

People have asked why passengers didn't get the driver's attention. Am I correct in thinking that the driver sits behind glass in his/her own cubicle? In any case, this is stiff-upper lip Britain where we don't like to make a fuss. Seriously.

 

Secondly, why does this system have drivers at all? It was built well after the driverless DLR and some LUL lines where the driver is apparently only there to "reassure" the passengers.

 

Ed

Because they are closed systems, whereas trams are on public roads and as we have seen already autonomous driving systems are less than 100% effective. Humans aren't exactly 100% effective either but are currently the better option in an open, uncontrolled environment.

[Broadway Clive]

Most socialising is done on early shifts as that is when one has the evening free, so quite often one goes to work having had very little sleep. Once when working as a guard on London's Underground I  closed my stinging eyes to rest them whilst sitting on one of the passenger seats next to my gangway. We were in the tunnel between stations and I must have drifted towards sleep for although I was aware when the train stopped at the next station I had by then 'become a passenger', and I kept my eyes closed waiting for the familiar sound of the doors opening. When that didn't happen I opened my eyes, and only then realised it was me who had to open the doors! That experience was a good lesson to learn for my future career as a motorman, and later as a manager of train crews when I had to investigate incidents like this one. It is the job of management to do risk assessments beforehand and I have to admit that I find these reserve track sections of the tramway too similar to a railway with two car trains to be treated any differently just because other sections have some street running.

[D854_Tiger]

I think you will find there was a desire by the DfT back in the late 80s to ensure the signs used for first modern tramway in the UK for decades (Manchester) could not be mistaken for conventional road signs. Going for a metric speed limit was a useful in assisting with this.

 

Well of course i'm not offering this as conclusive evidence over this debate.

 

Maybe not a tram driver but I think we all know there are plenty of car drivers out there that could confuse the two systems.

[ruggedpeak]

Most socialising is done on early shifts as that is when one has the evening free, so quite often one goes to work having had very little sleep. Once when working as a guard on London's Underground I closed my stinging eyes to rest them whilst sitting on one of the passenger seats next to my gangway. We were in the tunnel between stations and I must have drifted towards sleep for although I was aware when the train stopped at the next station I had by then 'become a passenger', and I kept my eyes closed waiting for the familiar sound of the doors opening. When that didn't happen I opened my eyes, and only then realised it was me who had to open the doors! That experience was a good lesson to learn for my future career as a motorman, and later as a manager of train crews when I had to investigate incidents like this one. It is the job of management to do risk assessments beforehand and I have to admit that I find these reserve track sections of the tramway too similar to a railway with two car trains to be treated any differently just because other sections have some street running.

My employer has a long list of questions that are put to anyone involved in a road collision about working patterns, when did your last shift end, when did you last sleep and eat etc. If you were not in a fit state to drive then the responsibility passes to the driver, although may be shared by supervisors if for example they knew the driver finished very late was back on shift a few hours later.

 

Exit to remove duplication.

Edited November 19, 2016 by ruggedpeak

[Titan]

 

 

The one issue that does worry me are the reports that taking this curve too fast may not have been an isolated event. It is said that when HST's were introduced there was a '140club' of drivers, complete with its own commemorative tie, for drivers who had achieved this magic figure. I have good reason to understand that this is not a fiction.

 

Not only is there good reason to think it is not fiction, I suspect it was totally legitimate. There were several test trains that were authorised to travel at high speed, there were probably half a dozen or more drivers that had travelled at that speed or more officially.

 

Not only that but I had two of the commemorative ties that were probably being referred to - they were official ones given out to everyone that was on or associated with the prototype HST when it broke the world record. They had a small print of the front of the prototype HST power car with 'HST 143' written on them IIRC. They came with a little card too. I donated one to the Deltic Preservation Society to auction to raise funds, and the post office lost the other...

[lapford34102]

Sadly we seem to have something of a culture, Amazon delivery for example, where safety/common sense comes a poor second to "productivity", for want of a better word.

 

Whether this was involved here I have no idea so will wait to see if there's a management aspect to this.

 

Stu

[The Stationmaster]

Just seen this pop up on the BBC news regarding the tram http://www.bbc.co.uk/news/uk-england-london-38036567

 

Does make me wonder whether it was reported previously and ignored. I doubt it very much but you never know

 

Gary

 

However while some of these reports appear genuine (and one is reportedly backed by correspondence with the operator) we should not overlook the fact that incidents like this very often draw all sorts of 'it nearly happened to me on that line' stories out of the woodwork.  Those investigating have also asked for information from users of the system which while potentially helpful in identifying any systemic problem, including managerial shortcomings, also encourages people to seek their 5 minutes of fame with something which might well have become 'enhanced' in their memory by this incident.   Hopefully the various investigators will be able to objectively assess this sort of information and stories of this nature.

 

Fortunately, and a little unusually, apart from some of them highlighting some of these stories many parts of the media seem to be behaving in a very responsible manner for once with mainly factual reporting and not much in the way of amateurish drawing of conclusions (many - but alas not all).

 

Overall i share the views and concerns expressed by JJB in Post 402 and those of David Hill about the difficulty of investigating the human factor and how it can work in such situations - one particular problem I have always found is the way in which memory works to either discount or ignore things which have been seen or have happened, usually without any sort of ulterior motive at all.  In fact it is usually easier to see through deliberate cover-ups or a group of witnesses working to their 'agreed script' than it is to deal with the frailties of the way the human mind and memory work.

[edcayton]

Sadly we seem to have something of a culture, Amazon delivery for example, where safety/common sense comes a poor second to "productivity", for want of a better word.

 

Whether this was involved here I have no idea so will wait to see if there's a management aspect to this.

 

Stu

 

Yes,but people (including me) buy stuff from Amazon knowing that they treat their non-employees like sh!t so we can save a few bob on stuff. Bit like our trains being made by low-paid people in China. And we wonder why we've got no industry left.

 

I'm all right Jack, pull up the ladder.

 

Ed

[david.hill64]

Not only is there good reason to think it is not fiction, I suspect it was totally legitimate. There were several test trains that were authorised to travel at high speed, there were probably half a dozen or more drivers that had travelled at that speed or more officially.

 

Not only that but I had two of the commemorative ties that were probably being referred to - they were official ones given out to everyone that was on or associated with the prototype HST when it broke the world record. They had a small print of the front of the prototype HST power car with 'HST 143' written on them IIRC. They came with a little card too. I donated one to the Deltic Preservation Society to auction to raise funds, and the post office lost the other...

I know there were legitimate overspeed test runs, but there were also problems with HST trailer cars throwing their brake discs which resulted in some 'by the back door' methods of recording train speed. At that time the union was set against any form of recording of trains functions so fitting portable data recorders was not on (and at the time these were not the micro machines that they are now.) The result was evidence of some liberal interpretation of limits!

[Fat Controller]

I was doing some background reading, a while ago regarding trams in their heyday. It would seem that trams operated a system and culture quite different from the "big railway" and few, if any if their operating staff had a "big railway" background.

 

London Underground seem to be very much "big railway" in their practices and culture. What is the situation regarding modern trams?

I knew two of the people involved in the commissioning stages and early driver training at Croydon; they had been involved in similar work at Eurotunnel, and prior to that, had worked at BR.

[ruggedpeak]

Overall i share the views and concerns expressed by JJB in Post 402 and those of David Hill about the difficulty of investigating the human factor and how it can work in such situations - one particular problem I have always found is the way in which memory works to either discount or ignore things which have been seen or have happened, usually without any sort of ulterior motive at all.  In fact it is usually easier to see through deliberate cover-ups or a group of witnesses working to their 'agreed script' than it is to deal with the frailties of the way the human mind and memory work.

This phenomenon is well documented, and there is considerable discussion and scientific work around the impact of traumatic events and recollection. This is exemplified over the current debate about to whether police officers should confer over notes after a firearms incident. Considerable learning in this field occured after a fatal and mistaken plice shooting some years ago.

 

I do not propose to discuss that issue, but it is scientific fact that our brains do not manage to collect, retain and recall all the information about situations, and this becomes more problematic if the incident was traumatic. Upon recall the brain automatically and unconciously fills in gaps of recollection with what it decides (based on all sorts of things) is best. We have no idea which bits of information are real and which are not. That is why people can swear blind that they recall something correctly and then be proved to be entirely wrong - your brain filters information and convinces you it is right even though it is not.