Croydon Tram Crash

neonison · 10 Nov 2016

robert7111a said:
Unconfirmed report is that the driver blacked out moments before the incident (heard on BBC London)

This has been mentioned on this thread before. It has been reported that this was said by the tram driver to a passenger immediately after the incident.

RailUK Forums

Ianno87 · 10 Nov 2016

Deepgreen said:
Conversely, why would a sign NOT be provided? If a tram/train is manually-controlled and the line speed changes dramatically, a sign is surely vital to ensure the correct speed is adhered to at the right place, even if only as a reminder/confirmation to the driver. It is arguable that an automatic system does not need signs, but I don't subscribe to the argument that geographical route knowledge alone is enough to ensure perfect speed profiles are maintained under a manual driving regime.

Manchester Metrolink has a highway-style chevron board at the point where the line sharply turns off the railway alignment onto the street-running section through Oldham, approaching from Manchester end.

That was slightly different in that there was a changeover, with drivers having previously been used to goung straight on through Werneth tunnels, before the town centre route opened.

LeylandLen · 10 Nov 2016

Todays Daily Mail says its a Bombardier CR4000 with a capacity of 70 seats with 138 standing .

edwin_m · 10 Nov 2016

Ianno87 said:
Manchester Metrolink has a highway-style chevron board at the point where the line sharply turns off the railway alignment onto the street-running section through Oldham, approaching from Manchester end.

That was slightly different in that there was a changeover, with drivers having previously been used to goung straight on through Werneth tunnels, before the town centre route opened.

Yes, I was chairing the safety workshop where a very wise man from the Metrolink operator (MRDL) asked for this and everyone agreed.
--- old post above --- --- new post below ---

Deepgreen said:
Impractical. It is a valid point, though, that very sharp curves adjacent to long fast stretches of route (compounded by being in tunnel close to the curve) have the potential to pose a risk of speed/track geometry misjudgement by the driver. The difference with light rail (being new rather than 'legacy') is that the geometry can be determined in the planning stage so as to minimise risk, OR an unavoidably 'dangerous' layout can have the risks mitigated via speed/approach control, but neither appears to have been done here. I also don't know if check rails were considered for such sharp curves, not that they would have made much difference at the likely speed involved, but they might be helpful at lower, but still excessive, speeds.
Of course, we only have speculation concerning a possible 'blackout' so far, but such events are very hard to account for without full automatic safety systems being installed, including a 'deadman' facility that is properly fail-safe.

The other difference with tramway operation (not necessarily other forms of light rail) is that the speed should be no greater than that from which it is possible to stop short of an obstruction, using only the service brake. Therefore, unlike a railway, early warning of speed restrictions is not necessary. There will be a retro-reflective sign at the start of the lower-speed section, which will be visible at the braking point, and it is then solely the responsibility of the driver to bring the tram down to a safe speed.

There is also the track ("hazard") brake, which approximately doubles the deceleration of the tram. It should not be used routinely but is available in situations such as late braking or unexpected poor adhesion. On the Croydon trams the use of the hazard brake also sounds the bell continuously (unless that's been changed since 1997), to warn those both inside and outside the tram. So trams do have other means of mitigating the risk of curve overspeeds, which may not be obvious to someone with heavy rail background.

In the light of this accident however, I do suspect we will end up with some sort of simple speed supervision system on trams, mainly to protect those places where a long high-speed section leads directly into a low-speed curve. However the nature of this system would depend on the exact reasons for this accident, which I don't wish to speculate about.

AlterEgo · 10 Nov 2016

Antman said:
I think a lot of people are jumping on the bandwagon, I've been on numerous trams around that curve and I've never felt the speed was excessive.

I've been on the tram a few dozen times (it was free when I had a priv!).

I paid particular attention at the junction as the layout is unusual, and follows a tunnel. I've never gone round it at anything more than 12mph.

chrisdmadd · 10 Nov 2016

AlterEgo said:
A tram is driven on sight with a braking potential similar to a conventional road vehicle.

Should we engineer all sharp turns out of 40/50mph roads in case a bus driver "has a blackout"?

I've never heard such rubbish.

A tram travelling at 80kph or whatever the speed is there stands no chance of avoiding a horrendous derailment if a driver for whatever reason fails to slow his tram down to the required 20kph for that bend.

A bus driver travelling at 80kph fails to slow to 20kph for a bend the outcome is entirely different. It's not on rails for one thing.

The risk assessment of a bus going round a bend and a tram going round a tight curve are somewhat different so please let's not make such stupid comments and think a little.

WatcherZero · 10 Nov 2016

Now understand why so many horrific injuries. It didn't just topple over but slid for several seconds on its side causing windows to smash and people to be ejected and crushed between the tram side and the tracks.

AlterEgo · 10 Nov 2016

chrisdmadd said:
I've never heard such rubbish.

A tram travelling at 80kph or whatever the speed is there stands no chance of avoiding a horrendous derailment if a driver for whatever reason fails to slow his tram down to the required 20kph for that bend.

A bus driver travelling at 80kph fails to slow to 20kph for a bend the outcome is entirely different. It's not on rails for one thing.

The risk assessment of a bus going round a bend and a tram going round a tight curve are somewhat different so please let's not make such stupid comments and think a little.

Sadly you totally misunderstood my post in its context.

Antman · 10 Nov 2016

chrisdmadd said:
I've never heard such rubbish.

A tram travelling at 80kph or whatever the speed is there stands no chance of avoiding a horrendous derailment if a driver for whatever reason fails to slow his tram down to the required 20kph for that bend.

A bus driver travelling at 80kph fails to slow to 20kph for a bend the outcome is entirely different. It's not on rails for one thing.

The risk assessment of a bus going round a bend and a tram going round a tight curve are somewhat different so please let's not make such stupid comments and think a little.

It's not that much different, either way a serious accident is likely to occur!
--- old post above --- --- new post below ---

WatcherZero said:
Now understand why so many horrific injuries. It didn't just topple over but slid for several seconds on its side causing windows to smash and people to be ejected and crushed between the tram side and the tracks.

I thought that much was fairly obvious?

chrisdmadd · 10 Nov 2016

AlterEgo said:
Sadly you totally misunderstood my post in its context.

You've edited your original response I see, anyway the guy made a fair comment about the curve and yours was just daft which made me question your sanity.

61653 HTAFC · 10 Nov 2016

Antman said:
There are no other tunnels on the network and I'm sure drivers are quite used to driving in the dark.

I don't think Groningen's post was ridiculous. The capacity of human beings to make mistakes is not to be underestimated. One of the reasons we persist with daylight-saving is that road accidents are statistically more likely in poor light conditions in the morning, than under the same conditions in the evening.

AlterEgo · 10 Nov 2016

chrisdmadd said:
You've edited your original response I see, anyway the guy made a fair comment about the curve and yours was just daft which made me question your sanity.

Please explain why it's daft, and what you, in your wisdom, might do better.

If a bus driver takes a 12mph hard left turn at 40-50mph, what will happen?

Why should a sharp tram curve be engineered out?

infobleep · 10 Nov 2016

daikilo said:
Without knowing the exact circumstaces, here are some indications.

Firstly, in general there need to be reasonable grounds for an "arrest", and causing death is probably one, if there is evidence that the driver's in/actions may have contributed.

As to counselling, the police making the arrest will advise the person of their legal rights. As the driver was at work, this may include the right to meet with an employer representative and/or possibly (in the presence of) a legal counsel. A driver may also have a right to counsel if s/he shows evidence of traumatic distress (however, this may be in the presence of others).

Thank you for clarifying that. I was interested in how it might work in the wider sense. Never an easy situation.

Sent from my SM-G925F using Tapatalk

SpacePhoenix · 10 Nov 2016

If the tram had been fitted with a driver's vigilance device would it have helped to prevent the accident at all?

ralphchadkirk · 10 Nov 2016

AlterEgo said:
Why should a sharp tram curve be engineered out?

Because it makes sense in a closed system with a relatively small pool of employees all trained to a standard competence level in similar vehicles with similar characteristics to engineer out a substantial risk in the infrastructure that, if done properly, could eliminate that risk?

Clip · 10 Nov 2016

ralphchadkirk said:
Because it makes sense in a closed system with a relatively small pool of employees all trained to a standard competence level in similar vehicles with similar characteristics to engineer out a substantial risk in the infrastructure that, if done properly, could eliminate that risk?

But that then cuts off 2 whole section of line and makes it pretty useless

Monty · 10 Nov 2016

SpacePhoenix said:
If the tram had been fitted with a driver's vigilance device would it have helped to prevent the accident at all?

No, because a vigilance device only stops the train if the driver does not manipulate any of the controls after a certain period of time. A TPWS type speed trap would be a much more appropriate device to avoid a incident such as this.

43096 · 10 Nov 2016

SpacePhoenix said:
If the tram had been fitted with a driver's vigilance device would it have helped to prevent the accident at all?

They do have a vigilance device as I understand it, on the PBC.

As for the "would it prevent it" question, that's probably best left to the RAIB to determine.

AlterEgo · 10 Nov 2016

ralphchadkirk said:
Because it makes sense in a closed system with a relatively small pool of employees all trained to a standard competence level in similar vehicles with similar characteristics to engineer out a substantial risk in the infrastructure that, if done properly, could eliminate that risk?

How would you engineer out this junction though? It looks like a necessary evil to me.

Busaholic · 10 Nov 2016

Deepgreen said:
Where the line speed limit is 50mph, why do you state that a tram should never, ever get anywhere near that permitted speed?

We shall see whether that speed limit survives the aftermath. I was very surprised to learn that it was allowed when it means the expected speed matches the capability of the tram. Just because my car (and I have a very modest one) is capable of 120 mph doesn't mean it should ever be attempted.

I will make a general comment here on frequencies. Until quite recent times and the introduction of new trams, especially with a tram 'missing' following the fatal accident involving a bus being driven in a criminal manner, there has been pressure on the Tramlink operators to get higher frequencies as the passengers using the system increase inexorably. Wimbledon only got an increase by diverting the more frequent 3 route from Addington to it rather than the 1 from Elmers End, and, as anyone who has ever been involved in public transport scheduling realises, if the resource and the distance to be covered is finite, then the only way to increase the frequency is by speeding up between stops, once you have got terminal times down to a minimum (given the problems at Wimbledon, it's obvious that has been done). In theory, you could spend less time at each intermediate stop, if it were not for those pesky passengers refusing to act like robots: in any case, with the increase in passenger numbers per tram journey this is an impossible dream. From memory, when Croydon Tramlink started in 2000 frequencies were every 7 minutes to Addington and every 10 minutes to Wimbledon, Elmers End and Beckenham weekday peak and shopping hours. Over the intervening years frequencies decreased, if anything, certainly to every 12 minutes from 10, and to 8 from 7, for some time. Now they are back up again, with the new 4 route increasing the Elmers End to Therapia Lane frequency. Now, whether the passengers and people living on the route(s) being quoted in the media are all being wise after the event, or plain misguided, there is an impression given of the system having speeded up over the last few months to, in the opinion of some, a dangerous level. The whole system and its operation will now come, rightfully, under enormous scrutiny.

Scott M · 10 Nov 2016

WatcherZero said:
Now understand why so many horrific injuries. It didn't just topple over but slid for several seconds on its side causing windows to smash and people to be ejected and crushed between the tram side and the tracks.

Yes, CNN reporting one of the survivors was wondering where his friend was as he could only see his boots where he was previously sitting. Turned out he was right beneath him crushed under the tram.

Antman · 10 Nov 2016

Busaholic said:
We shall see whether that speed limit survives the aftermath. I was very surprised to learn that it was allowed when it means the expected speed matches the capability of the tram. Just because my car (and I have a very modest one) is capable of 120 mph doesn't mean it should ever be attempted.

I will make a general comment here on frequencies. Until quite recent times and the introduction of new trams, especially with a tram 'missing' following the fatal accident involving a bus being driven in a criminal manner, there has been pressure on the Tramlink operators to get higher frequencies as the passengers using the system increase inexorably. Wimbledon only got an increase by diverting the more frequent 3 route from Addington to it rather than the 1 from Elmers End, and, as anyone who has ever been involved in public transport scheduling realises, if the resource and the distance to be covered is finite, then the only way to increase the frequency is by speeding up between stops, once you have got terminal times down to a minimum (given the problems at Wimbledon, it's obvious that has been done). In theory, you could spend less time at each intermediate stop, if it were not for those pesky passengers refusing to act like robots: in any case, with the increase in passenger numbers per tram journey this is an impossible dream. From memory, when Croydon Tramlink started in 2000 frequencies were every 7 minutes to Addington and every 10 minutes to Wimbledon, Elmers End and Beckenham weekday peak and shopping hours. Over the intervening years frequencies decreased, if anything, certainly to every 12 minutes from 10, and to 8 from 7, for some time. Now they are back up again, with the new 4 route increasing the Elmers End to Therapia Lane frequency. Now, whether the passengers and people living on the route(s) being quoted in the media are all being wise after the event, or plain misguided, there is an impression given of the system having speeded up over the last few months to, in the opinion of some, a dangerous level. The whole system and its operation will now come, rightfully, under enormous scrutiny.

Stop being so dramatic, I use the system regularly and it is perfectly safe.

martin2345uk · 10 Nov 2016

Metrolink trams also have top speed of 50mph and they frequently achieve it on the segregated lines.

Antman · 10 Nov 2016

AlterEgo said:
How would you engineer out this junction though? It looks like a necessary evil to me.

Exactly, the mind boggles as to how anybody seriously expects it to be altered?

507 001 · 10 Nov 2016

43096 said:
They do have a vigilance device as I understand it, on the PBC.

As for the "would it prevent it" question, that's probably best left to the RAIB to determine.

They don't have vigilance, they do have a DSD, there is a difference.

Busaholic said:
We shall see whether that speed limit survives the aftermath. I was very surprised to learn that it was allowed when it means the expected speed matches the capability of the tram. Just because my car (and I have a very modest one) is capable of 120 mph doesn't mean it should ever be attempted.

A frankly ridiculous comparison.

Do you not think that the manufacturer would test the vehicles at their intended top speed?

Flexity swift vehicles have been running at 50mph in this country and around the world for the best part of 20 years. They are actually capable of higher speeds, however in this country they are restricted to 50MPH. In fact when Koln purchased their K5000 vehicles their original intention was to run them at 100kph/62mph.

Robertj21a · 10 Nov 2016

Busaholic said:
We shall see whether that speed limit survives the aftermath. I was very surprised to learn that it was allowed when it means the expected speed matches the capability of the tram. Just because my car (and I have a very modest one) is capable of 120 mph doesn't mean it should ever be attempted.

I will make a general comment here on frequencies. Until quite recent times and the introduction of new trams, especially with a tram 'missing' following the fatal accident involving a bus being driven in a criminal manner, there has been pressure on the Tramlink operators to get higher frequencies as the passengers using the system increase inexorably. Wimbledon only got an increase by diverting the more frequent 3 route from Addington to it rather than the 1 from Elmers End, and, as anyone who has ever been involved in public transport scheduling realises, if the resource and the distance to be covered is finite, then the only way to increase the frequency is by speeding up between stops, once you have got terminal times down to a minimum (given the problems at Wimbledon, it's obvious that has been done). In theory, you could spend less time at each intermediate stop, if it were not for those pesky passengers refusing to act like robots: in any case, with the increase in passenger numbers per tram journey this is an impossible dream. From memory, when Croydon Tramlink started in 2000 frequencies were every 7 minutes to Addington and every 10 minutes to Wimbledon, Elmers End and Beckenham weekday peak and shopping hours. Over the intervening years frequencies decreased, if anything, certainly to every 12 minutes from 10, and to 8 from 7, for some time. Now they are back up again, with the new 4 route increasing the Elmers End to Therapia Lane frequency. Now, whether the passengers and people living on the route(s) being quoted in the media are all being wise after the event, or plain misguided, there is an impression given of the system having speeded up over the last few months to, in the opinion of some, a dangerous level. The whole system and its operation will now come, rightfully, under enormous scrutiny.

You do realise that they have also been putting extra, new, trams into service at Croydon ?

Clip · 10 Nov 2016

ES are reporting that some people felt a tram tilt there less than a week ago through going too fast
http://www.standard.co.uk/news/lond...-in-same-spot-a-week-previously-a3392941.html

Police are investigating passengers reports that a tram almost came off the tracks a week ago in the same place as Wednesdays fatal crash.

Six men and one woman were killed and 51 were injured when a two-carriage vehicle derailed on a sharp bend near Sandilands stop in Croydon shortly after 6am.

The driver, a 42-year-old man from Beckenham, was today bailed after being questioned by police on suspicion of manslaughter.

Rail investigators believe the tram packed with commuters traveling to East Croydon station - was travelling at a significantly higher speed than the 12mph limit.

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Resident speaks about witnessesing tram crash aftermath: 'He must have been going too fast'
It has now been revealed that a week previously commuters posted ominous comments on Facebook describing how their tram lifted onto one side in the same spot.

Andy Nias, from Croydon, wrote: Oh mate... 30 of us on the tram this morning and we all thought our time was up. Tram driver took the hard corner to Sandilands at 40mph!! I swear the tram lifted onto one side. Everyone still shaking... it's mad

He added: I'm not afraid of death but wouldn't want to be in a tram accident... mate I was shaking bad. Just don't know where you would end up.

Another commuter, James Tofield, said he had been on the tram as well, adding: It was like a ride from Alton Towers.

RobShipway · 10 Nov 2016

For me it is not a case that the curve needs to be re - designed, it is that as I have stated previously in this thread safety warning signs before getting to the end of the tunnel need to be be put up and the whole of the Croydon Tramlink system needs to have something similar to TPWS fitted within it that can also be used with the sections of tramway that exist within any roads that it ravels along.

The problem is not with the trams themselves, it is with the Infrastructure that the trams run on.

30907 · 10 Nov 2016

For info: the German thread on this topic (much briefer and more factual) refers to similar accidents in Duesseldorf and (years ago) Stuttgart.
http://www.drehscheibe-online.de/foren/read.php?5,7990439

Changing tack slightly, the saga of the introduction of AWS magnets to protect heavily speed-restricted curves (Morpeth...) is a relevant heavy-rail comparison

LeeLivery · 10 Nov 2016

Theres nothing wrong with how fast the tram can go or a high line speed, as long as its in a good location. Working in Croydon, I know the system well, but have never travelled on the Addington branch. However, using the Beckenham/Elmers branch quite a bit, I've never felt unsafe on the curve. I do find it surprising that the line speed in the tunnel is 80kph seeing both ends have sharp curves. I don't use the tram often so I can't comment on whether trams are driving faster recently.

Croydon Tram Crash

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