Croydon Tram Accident

[leopardml2341]

.  

 

The word "you" may have personalised it if you take the word as being in the second person singular, but it not infer anything.  

 

You may think it was an accident or you may think it was not. 

You made the inference not me.

 

Also take my comments in the context of this thread.  

 

Several posters are quire sensibly discussing the use of the word accident (not inferring that you were not by the way) and it is clear that the only alternative to an accident is something that was done deliberately.

I thought you had have difficultly with that point, so I made a comment in an effort to explain it but you took it as a personal inference.

 

 

The phrase "No more debate needed" comes across to me as arrogant, by the way.  

 

Feel free to continue the debate if you wish but please do not try to bring it to a premature end after making a point.

 

No need for Mods to lock the thread just because the word "accident" is being discussed IMHO

Thank You for the kind offer, but I feel no burning desire to continue the debate along those lines.

 

Mallard60022's post has been deleted, but I still support his sentiment of keeping the topic on track and the question of whether it was truly an accident will be no doubt answered in the fullness of time by the RAIB report.

Edited November 17, 2016 by leopardml2341

[Andy Y]

Time to head back to the topic please.

[leopardml2341]

Time to head back to the topic please.

Thanks Andy

[Colin_McLeod]

Thanks Andy

[Dagworth]

One thing I have spotted & I don't recall anyone mentioning this, in this thread.

 

In the preliminary RAIB report, it clearly depicts in the diagram, a 20 kilometre an hour restriction board. However, all mentions of it elsewhere (learned RMweb members and news items, such as the BBC) all refer to it being a 12 1/2 Mile an Hour speed limit at the end of a 50 mph zone.

 

Did this contribute to the problem, with a potential confusion as to what the speed limit actually is? Yes, I do realise that it was apparently well in excess of either way of calculating it, but the doubt could be there.

 

It strikes me as odd that specific TRAM speed limits, are apparently in KMH, yet the normal road sign speed limits in MPH.

 

That raises the obvious question, why doesn't Britain have one system of identifying speed limits and not BOTH? Yes, MPH is traditional, but why is the tram line different? After all tram drivers have to navigate both types of speed signs, on reserved tracks & public roads.

As long as both the speed signs and the speedometer are in the same units it makes no difference what those units might be. They could both be tramlengths per restbreak, all that matter is that the number on the speed board is the same as the one on the speedo.

 

Croydon tram speedometers are marked in kph with a max speed of 80 kph which equates to 50 mph.

 

That the media have done the conversions I would think is only to make it easier for the man in the street to be able to visualise.

 

http://www.croydon-tramlink.co.uk/info/trams/control.shtml

 

Andi

Edited November 17, 2016 by Dagworth

[47137]

...

 

It strikes me as odd that specific TRAM speed limits, are apparently in KMH, yet the normal road sign speed limits in MPH.

 

That raises the obvious question, why doesn't Britain have one system of identifying speed limits and not BOTH? Yes, MPH is traditional, but why is the tram line different? After all tram drivers have to navigate both types of speed signs, on reserved tracks & public roads.

In Britain, the Highway Code UK Government book 'Know Your Traffic Signs' explains the speed limit signs for trams (black figures on white diamonds):

Speed limit sign for tram drivers shown in kilometres per hour. All diamond-shaped signs are for tram drivers only

 

I cannot find an example in Google Street View (no trams near home to look at) but maybe someone can confirm, trams have their own speed limit signs throughout, including their street sections?

 

- Richard. 

 

Edit for correctness.

Edited November 17, 2016 by 47137

[pete_mcfarlane]

In Britain, the Highway Code explains the speed limit signs for trams (black figures on white diamonds):

Speed limit sign for tram drivers shown in kilometres per hour. All diamond-shaped signs are for tram drivers only

 

I cannot find an example in Google Street View (no trams near home to look at) but maybe someone can confirm, trams have their own speed limit signs throughout, including their street sections?

 

- Richard. 

 

Here's a couple from Nottingham:

 

This is where trams leave the city centre street running section, and head north towards the scenic delights of Bulwell and Hucknall. 

https://www.google.co.uk/maps/@52.9722896,-1.1797825,3a,75y,334.69h,69.22t/data=!3m6!1e1!3m4!1s0wSsTbmyBtJLZafNri2Prw!2e0!7i13312!8i6656

 

10Kph round this curve near the Forest

https://www.google.co.uk/maps/@52.9666279,-1.1687275,3a,75y,60.61h,82.38t/data=!3m6!1e1!3m4!1s3yF-yGwdGUeP7kQdtkR0Lw!2e0!7i13312!8i6656

[dhjgreen]

In Britain, the Highway Code UK Government book 'Know Your Traffic Signs' explains the speed limit signs for trams (black figures on white diamonds):

Speed limit sign for tram drivers shown in kilometres per hour. All diamond-shaped signs are for tram drivers only

 

I cannot find an example in Google Street View (no trams near home to look at) but maybe someone can confirm, trams have their own speed limit signs throughout, including their street sections?

 

- Richard. 

 

Edit for correctness.

Metrolink all in mph,

[Geoff Endacott]

Perhaps the use of the word accident was an accident.

 

Geoff Endacott

[ruggedpeak]

Even if there was a 20kph board, the tram was still doing 43mph. So it doesn't matter if the driver thought the limit was 12.5 or 20 mph or kph, the tram reportedly went into the curve at 43mph or 69kph. However confused a driver might have been between 12 or 20 miles or km an hour, the tram was far beyond any permutation of misunderstood limits.

 

I also understand that the scene was very traumatic and emergency services personnel have been affected by it, as well as the pasengers. Thanks to all involved.

Edited November 17, 2016 by ruggedpeak

[ejstubbs]

if other drivers including this one, could say that they always took the bend at that speed ... and the speed was accepted as the norm by usage, then the derailment and overturn could be considered as unexpected.

 

I very much doubt that anyone had attempted to take a tram through that bend at that speed before.  The consequences of doing so were far from unexpected.  The RAIB's preliminary report says that the tram was going way too fast, and that's why it left the rails - it doesn't leave much doubt that that's what would be expected to happen if you did that.

Edited November 17, 2016 by ejstubbs

[ruggedpeak]

I very much doubt that anyone had attempted to take a tram through that bend at that speed before.  The consequences of doing so were far from unexpected.  The RAIB's preliminary report says that the tram was going way too fast, and that's why it left the rails - it doesn't leave much doubt that that's what would be expected to happen if you did that.

There are clear reports and complaints of another tram being driven by another driver (confirmed by Tramlink) going around the same bend with excessive speed and "lifting on one side" on at least one occasion in recent weeks (see one of my earlier posts http://www.rmweb.co.uk/community/index.php?/topic/116642-croydon-tram-accident/page-13&do=findComment&comment=2500863 ).

 

How relevant this will be to the investigation conclusions we shall see, but it certainly appears pertinent and at first glance suggests the excess speed on the bend might not necessarily be a one-off or freak incident.

Edited November 17, 2016 by ruggedpeak

[Edwin_m]

There are clear reports and complaints of another tram being driven by another driver (confirmed by Tramlink) going around the same bend with excessive speed and "lifting on one side" on at least one occasion in recent weeks (see one of my earlier posts http://www.rmweb.co.uk/community/index.php?/topic/116642-croydon-tram-accident/page-13&do=findComment&comment=2500863 ).

 

How relevant this will be to the investigation conclusions we shall see, but it certainly appears pertinent and at first glance suggests the excess speed on the bend might not necessarily be a one-off or freak incident.

My strong suspicion is that "lifting off the rail" is actually the vehicle rolling out and back on its suspension.  If one side of a tram (or train) lifts off the rail on a curve, then that will also lift the centre of gravity and therefore increase the tendency to continue into full overturn.  Despite the fact it happened in that film, I think it's incredibly unlikely that a rail vehicle can lift off the rail on a curve and drop back again. 

[BobM]

Awful event for everyone involved....thoughts and prayers eh folks.....

Edited November 17, 2016 by BobM

[ruggedpeak]

My strong suspicion is that "lifting off the rail" is actually the vehicle rolling out and back on its suspension.  If one side of a tram (or train) lifts off the rail on a curve, then that will also lift the centre of gravity and therefore increase the tendency to continue into full overturn.  Despite the fact it happened in that film, I think it's incredibly unlikely that a rail vehicle can lift off the rail on a curve and drop back again. 

I think the issue is the fact that excess speed through that curve may not have been a one off event. The "lifting" comment is a direct quote from a passenger who experienced the situation. Whether the wheels lifted or not, if passengers felt that then something is wrong and it should not have occured in normal operation.

[JDW]

In terms of the actual speed limits and signage, I don't think it really matters whether they are in mph or kmh, as someone said above, what matters is that the signs and speedo match.  They don't switch between the two, so there should be little scope for confusion, and even on street sections where trams use kmh and cars use mph, the two are usually closely aligned (30mph/50kmh etc).

[Gwiwer]

 

 

even on street sections where trams use kmh and cars use mph, the two are usually closely aligned (30mph/50kmh etc).

Agreed.  And for the many of us with European or other overseas (Australian and NZ in my case) driving experience we too are familiar with kmh and the fact that the actual speed of our vehicle is very much the same however it is measured. While specific detail can probably be specified for instrumentation it is normal for trams to have speedometers calibrated in kmh.  Your car probably has kmh also though in smaller digits than the mph ones.

 

It takes a great deal of energy to lift a railed vehicle sufficiently to have its centre of gravity elevated to the point of no return.  Multiple forces would be in play for a moving tram entering a curve but it is normal for passengers to "feel" the curve even at the prescribed 20kmh limit.  The greater any overspeed the greater would be the apparent sensation of leaning to the outside of the curve for those aboard.

 

I doubt any other tram has left the rails even momentarily but agree with comments above that there is sufficient "give" in the suspension when combined with the normal effects of curvature to alarm passengers experiencing a significant overspeed event.  In my rather limited experience of Croydon Tramlink the driving has been on a par with that in my current location of Melbourne and has ranged from the truly professional to the keen-to-make-up-time heavy-boot style of fierce stopping and starting.  I was never in a position to observe the actual speed but never felt it to be excessive.

[david.hill64]

In terms of the actual speed limits and signage, I don't think it really matters whether they are in mph or kmh, as someone said above, what matters is that the signs and speedo match.  They don't switch between the two, so there should be little scope for confusion, and even on street sections where trams use kmh and cars use mph, the two are usually closely aligned (30mph/50kmh etc).

I am not disagreeing with you but will offer an alternative view.

 

As a car driver I think I have a reasonable estimate of how fast I am doing without looking at the speed limit. If I see a posted speed limit of 30mph I can get very close to that without having to read the speedo every 5 seconds and I think I am not alone. So I wonder if subconsciously there is a confusion if you are used to driving a car with limits posted in mph and then get into a tram where limits are posted in km/h? Is there a danger that your brain will register a 50km/h sign and your natural reaction is to control to 50mph? 

 

Not an issue in this case as the overspeed was reported by RAIB as being severe.

[Reorte]

I am not disagreeing with you but will offer an alternative view.

 

As a car driver I think I have a reasonable estimate of how fast I am doing without looking at the speed limit. If I see a posted speed limit of 30mph I can get very close to that without having to read the speedo every 5 seconds and I think I am not alone. So I wonder if subconsciously there is a confusion if you are used to driving a car with limits posted in mph and then get into a tram where limits are posted in km/h? Is there a danger that your brain will register a 50km/h sign and your natural reaction is to control to 50mph? 

 

Not an issue in this case as the overspeed was reported by RAIB as being severe.

I spend 15 months in France, so was driving against km/h signs. It took a bit of careful checking at first but I soon got used to it. It was probably helped by generally having roughly the same speed limit (50 km/h or 30 mph etc.) in the same sort of environment.

[ejstubbs]

There are clear reports and complaints of another tram being driven by another driver (confirmed by Tramlink) going around the same bend with excessive speed and "lifting on one side" on at least one occasion in recent weeks (see one of my earlier posts http://www.rmweb.co.uk/community/index.php?/topic/116642-croydon-tram-accident/page-13&do=findComment&comment=2500863 ).

 

I'm not quite sure what point you're trying to make.  In none of those incidents did the tram leave the rails.  I seriously doubt that Mr Christian had the slightest clue about what was actually happening at the rail/wheel interface, and his estimate of the speed cannot reasonably be relied upon to be particularly accurate (both assertions are far more likely to be Farcebook hyperbole IMO).

 

Yes, those reports appear to offer evidence of previous poor observance of the speed limit on that curve.  That's really nothing to do with whether derailment is an unexpected consequence of entering the curve at 70kph rather than the posted limit of 20kph, which is what Lady_Ava_Hay appeared to be trying to argue, and what I was responding to.

 

Two reports known of to date out of the thousands of times that trams must have traversed that section of track does not in itself prove that drivers had become habituated to taking the curve at ~40mph.  And, even if they had, the fact that there is a much lower speed limit there is a clear indication to anyone with half a brain* that what you might be doing out of habit (which is yet to be proven) cannot reasonably be expected to be consequence-free.

 

That's the point I was trying to make.

 

* I don't know what First's criteria are for selection of tram divers but I would expect them to require a rather better level of intellectual capability than that.

Edited November 18, 2016 by ejstubbs

[edcayton]

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.

 

This is speculation. There could have been a fault with the tram. It also looks as though there was an "accident waiting to happen" with this corner, but can we please wait for the full enquiry results?

 

Ed

[meil]

I think the point is if it is a one-off then the driver is in trouble. If it is a habitual habit amongst drivers and the operator knew about then they are in trouble as well.

Edited November 18, 2016 by meil

[The Stationmaster]

I think the point is if it is a one-off then the driver is in trouble. If it is an habitual habit amongst drivers and the operator knew about they are in trouble as well.

 

Exactly so - especially if there is evidence (as has allegedly been stated by at least one source) that passengers concerns about speed at that location were reported to the operator.

 

However I think we must always take 'passenger's concerns' with a small pinch of salt as we all tend to view things in different ways and my sensation or opinion of, say, the speed at a particular spot could be different from that of others as well as having a different opinion of the normal speed at that point.  However where such reports do exist I have no doubt that the various investigators will examine them in some depth to establish their veracity and relevance.

[beast66606]

 

However I think we must always take 'passenger's concerns' with a small pinch of salt

 

Indeed - on one journey a few years back I had to explain first wheel replacement (of signals) to a lady who was getting a bit hysterical thinking we had gone passed a signal at danger, it wasn't long after one of the major crashes so people were on edge.

[dhjgreen]

Exactly so - especially if there is evidence (as has allegedly been stated by at least one source) that passengers concerns about speed at that location were reported to the operator.

 

However I think we must always take 'passenger's concerns' with a small pinch of salt as we all tend to view things in different ways and my sensation or opinion of, say, the speed at a particular spot could be different from that of others as well as having a different opinion of the normal speed at that point.  However where such reports do exist I have no doubt that the various investigators will examine them in some depth to establish their veracity and relevance.

They could have been looking over the driver's shoulder, you can see the speedo on Metrolink. The blind might have been down on this particular tram because of the time of day.