Lumo overspeed incident at Peterborough (17/04/2022)

[Nottingham59]

Can someone explain the sequence of signals that would (should) have been displayed before the cross-over, please? Especially, whether the turnout is signalled by feathers or a route indicator board?

I am struck by similarities with the derailment at Bletchley in 2012, which may or may not have parallels with this case: https://www.gov.uk/raib-reports/derailment-at-bletchley-junction-bletchley

 

[43096]

If you mean the Münchendorf derailment, that appears to have happened on plain line, from photographs in the press.

The photos in this piece show different (https://www.oe24.at/oesterreich/chr...okoll-todes-zug-war-viel-zu-schnell/519053130) as they've already started reinstating the track.

 

[Bertie the bus]

The press team as well the management were under immediate and severe press pressure to explain why the passengers had been injured so a bland statement saying that something had happened and was under investigation wasn’t going to cut it.

At that time it wasn’t known how many of the injuries were caused by an emergency brake application (which is really fierce on these units - if not secure, you and your luggage will “fly” down the carriage. I have done it on test - not pleasant) and how much was due to the lurch through the points and the continuing rapid deceleration. The speed of the train through the points was not known at that time, nor was when he put the lot in.

So the release concentrated on what was known - that a rapid deceleration would cause displacement of passengers and luggage. It had nothing to do with “protecting reputation” as an incident like this is a reputation breaker on it’s own - in transport the number one priority is “a safe arrival”, not bouncing your punters around inside your own vehicles and causing them harm.

I find that extremely hard to believe. It was known 2 things occurred, overspeed through points and an emergency brake application, but only the latter was mentioned because it was not known which caused the injuries. Why, if it wasn’t a deliberate attempt to hide the truth, was it not only the former that was mentioned? Especially when at the time all the noise from social media was saying luggage fell off the racks causing injuries when the train was lurching from side to side.

 

[ComUtoR]

I struggle to see how crossing points at 3 times the speed limit can be 'outside the control of the driver'

The train could have been in an uncontrolled slide.

 

[TheBigD]

Can someone explain the sequence of signals that would (should) have been displayed before the cross-over, please? Especially, whether the turnout is signalled by feathers or a route indicator board?

I am struck by similarities with the derailment at Bletchley in 2012, which may or may not have parallels with this case: https://www.gov.uk/raib-reports/derailment-at-bletchley-junction-bletchley

My understanding is that the lumo followed an EMR service from Stoke Jcn (booked to do so) which crosses over at Peterborough to platforms 4/5/6/7. That Junction is 15 mph. The lumo would have approached P468 at red, whilst the EMR crossed over, P468 would have then changed to a green with the route indication for the up slow/platform 1.

Happy to be corrected though.

 

[800001]

The press team as well the management were under immediate and severe press pressure to explain why the passengers had been injured so a bland statement saying that something had happened and was under investigation wasn’t going to cut it.

At that time it wasn’t known how many of the injuries were caused by an emergency brake application (which is really fierce on these units - if not secure, you and your luggage will “fly” down the carriage. I have done it on test - not pleasant) and how much was due to the lurch through the points and the continuing rapid deceleration. The speed of the train through the points was not known at that time, nor was when he put the lot in.

So the release concentrated on what was known - that a rapid deceleration would cause displacement of passengers and luggage. It had nothing to do with “protecting reputation” as an incident like this is a reputation breaker on it’s own - in transport the number one priority is “a safe arrival”, not bouncing your punters around inside your own vehicles and causing them harm.

The speed of the train approaching the points, over the points and also how quickly the train came to a stand, were known to the people who needed to know within a matter of minutes of the incident occurring.

The train could have been in an uncontrolled slide.

It wasn’t.

 

[43066]

The speed of the train approaching the points, over the points and also how quickly the train came to a stand, were known to the people who needed to know within a matter of minutes of the incident occurring.

Nobody is going to write any of that into an initial statement, though. If anything they should have been a lot blander.

 

[800001]

Nobody is going to write any of that into an initial statement, though. If anything they should have been a lot blander.

Fully appreciate that, and also as it would most likely of ended up being an investigation, speed etc would not be something they would wish to discuss in a press release etc.
My answer was more aimed at the person saying speed would of been unknown at the time they issued press release.

 

[6Gman]

The press team as well the management were under immediate and severe press pressure to explain why the passengers had been injured so a bland statement saying that something had happened and was under investigation wasn’t going to cut it.

At that time it wasn’t known how many of the injuries were caused by an emergency brake application (which is really fierce on these units - if not secure, you and your luggage will “fly” down the carriage. I have done it on test - not pleasant) and how much was due to the lurch through the points and the continuing rapid deceleration. The speed of the train through the points was not known at that time, nor was when he put the lot in.

So the release concentrated on what was known - that a rapid deceleration would cause displacement of passengers and luggage. It had nothing to do with “protecting reputation” as an incident like this is a reputation breaker on it’s own - in transport the number one priority is “a safe arrival”, not bouncing your punters around inside your own vehicles and causing them harm.

I'm interested by this. I can understand that the primary aim of an emergency brake application is to bring the train to a stop as quickly as possible, BUT there is presumably a need to balance that against the risk of an over-rapid deceleration. My only recent experience is of a Voyager which found itself wrapped up in fallen wiring. The emergency brake application brought us to a stop which was both rapid and smooth, which seemed the appropriate balance. It so happened I was walking down the carriage as it happened and I certainly wasn't thrown off my feet or anything.

 

[357]

I'm interested by this. I can understand that the primary aim of an emergency brake application is to bring the train to a stop as quickly as possible, BUT there is presumably a need to balance that against the risk of an over-rapid deceleration. My only recent experience is of a Voyager which found itself wrapped up in fallen wiring. The emergency brake application brought us to a stop which was both rapid and smooth, which seemed the appropriate balance. It so happened I was walking down the carriage as it happened and I certainly wasn't thrown off my feet or anything.

An emergency brake application can't see what the driver can see and doesn't know how much space is available.

A driver doesn't necessarily need to use emergency if they can comfortable stop the train safely short of any danger otherwise.

The rapid deceleration could be better than a collision with an oil tanker on a level crossing for example.

I'd always support emergency applications stopping the train as fast as possible

 

[GC class B1]

Or realised that he had made a total mess of it and needed to brake quick to try and rescue the situation.
I struggle to see how crossing points at 3 times the speed limit can be 'outside the control of the driver'

I think you have misunderstood my post. stating an emergency brake application suggests something unexpected occurred and the driver responded as would be required. Stating Overspeeding may be taken to imply driver error and therefore could be more of a concern to passengere.

 

[gazzaa2]

It's a good job the train wasn't overcrowded. It just shows it's a real potential safety hazard when you've got scores of people standing in carriages, in addition to full seating.

 

[Clarence Yard]

The speed of the train approaching the points, over the points and also how quickly the train came to a stand, were known to the people who needed to know within a matter of minutes of the incident occurring.

It wasn’t. There was conflicting advice given as to the speed and the exact braking sequence which is another reason why the Press Statement went out like it did.

What I couldn’t understand was when the actual facts were established as correct, some kind of clarification wasn’t issued. Perhaps the “Press Moment” had passed but I would have done it without throwing the Driver under the bus in doing so.

An 80x unit will brake at 12.5%g in emergency. An HST will brake at 9%g with no extra emergency capability.

 

[800001]

It wasn’t. There was conflicting advice given as to the speed and the exact braking sequence which is another reason why the Press Statement went out like it did.

What I couldn’t understand was when the actual facts were established as correct, some kind of clarification wasn’t issued. Perhaps the “Press Moment” had passed but I would have done it without throwing the Driver under the bus in doing so.

An 80x unit will brake at 12.5%g in emergency. An HST will brake at 9%g with no extra emergency capability.

I disagree. The speed, the acceleration and deceleration and over what period was known to the people who needed to know very very quickly.
How that information was used was up to Lumo/first group, but i can 100% say that all the speed information was known to the relevant people with in minutes.

 

[ComUtoR]

It wasn’t.

I'm well aware.

My response was to a post where someone stated that they did not understand how crossing 3 sets of points at speed would be out of the Drivers control. As highlighted so very recently; trains can, and will side.

 

[Nottingham59]

The lumo would have approached P468 at red, whilst the EMR crossed over, P468 would have then changed to a green with the route indication for the up slow/platform 1.

Thank you. That is very helpful. So, if a train were approaching P468 at Red, expecting to stop, and P468 changed from Red to Green, how long would the Green signal (and its route indicator) be visible to the driver before they passed the signal? (And I'm not saying this is what happened; I'm just trying to understand the characteristics of the signalling system.)

 

[Clarence Yard]

I disagree. The speed, the acceleration and deceleration and over what period was known to the people who needed to know very very quickly.
How that information was used was up to Lumo/first group, but i can 100% say that all the speed information was known to the relevant people with in minutes.

And I repeat, there was more than one version of the truth being communicated to Lumo/FG at that time. That isn’t unknown in incidents like this and with the press breathing down your neck (fuelled by social media postings) you have to make a judgement as to what to put out, all in very short order.

 

[Wyrleybart]

I disagree. The speed, the acceleration and deceleration and over what period was known to the people who needed to know very very quickly.
How that information was used was up to Lumo/first group, but i can 100% say that all the speed information was known to the relevant people with in minutes.

And will be incorporated into the RAIB report i am sure.
until then we can rest easy

 

[Newshound Mutt]

Can we just not wait until the official report is published? Lock the thread maybe?

 

[yorkie]

I struggle to see how crossing points at 3 times the speed limit can be 'outside the control of the driver'

There are circumstances in which it can happen, but it seems unlikely in this case, but the report will reveal all I'm sure.

Can we just not wait until the official report is published? Lock the thread maybe?

If anyone has any suggestions for the moderation team, such as a proposal to lock the thread, this should exclusively be made via the report button or contact form please, thanks

 

[158747]

Can we just not wait until the official report is published? Lock the thread maybe?

Or alternatively keep the thread open and let those who wish to comment have their say as they see fit.

 

[Clarence Yard]

Away from the exact circumstances here, the reference upthread to the Bletchley report is interesting. We, the industry, have been putting faster accelerating kit onto the network but the signalling system is still, in places, that designed for another era of train performance.

Reducing drivers “thinking time” is a by-product of this policy. Whilst much is (rightfully) made of making braking distances, what of the dangers of reducing the time to absorb what you see in front of you? Of course the long term answer is to do away with the need for any signals at all.

But in the interim it does put a greater onus on operators to make sure their drivers actually do know the routes they drive over, especially the layouts (such as Peterborough) where you can easily be moved off your “usual” route.

 

[PG]

An 80x unit will brake at 12.5%g in emergency. An HST will brake at 9%g with no extra emergency capability.

Would someone be kind enough to explain how much quicker, assuming the higher rate doesn't cause a slide, the 80x will stop from a given speed than the HST?

Additionally:
Was this higher emergency braking capability part of IET specification?

Thanks

 

[Scott M]

Can’t wrap my head around why the driver would ignore the flashing yellows unless he had a death wish. Can only assume he thought the turn off was 75 instead of 25.

 

[2HAP]

he photos in this piece show different (https://www.oe24.at/oesterreich/chr...okoll-todes-zug-war-viel-zu-schnell/519053130) as they've already started reinstating the track.

Thank you, hadn't seen an aerial view.

 

[GC class B1]

Would someone be kind enough to explain how much quicker, assuming the higher rate doesn't cause a slide, the 80x will stop from a given speed than the HST?

Additionally:
Was this higher emergency braking capability part of IET specification?

Thanks

As an approximation 9%g for the HST is a deceleration rate of 0.9 m/s/s. 12.5%g is a deceleration rate of 1.25 m/s/s. The stopping distance is calculated by adding the distance travelled during the brake build up time and the distance travelled during the brake application. The distance travelled during the brake application is calculated using the formula distance (s) = the squared of the initial speed divided by 2 x deceleration (f). Assuming a speed of 33m/sec (approx 75 MPH) and a brake build up time of 2 seconds for both trains, the stopping distances will be as follows.
HST will be 66 + 605 = 671 metres. Class 800 will be 66 + 436. = 502 metres. The stoping distance for the class 800 is nearly 200 metres shorter than an HST ignoring all other factors.

My understanding is that the class 800 are designed for a maximum speed of 140MPH and have a Full Service deceleration rate of 10% in order to comply with the requirements of GM/RT2045 issue 4. HST have a maximum speed of 125 MPH and have a Full Service deceleration rate 9%g which meets the stopping distance requirement. Since before privatisation multiple units have required what was termed as enhanced emergency braking at 12% g.

 

[norbitonflyer]

Because the initial press release was carried in all the news media on the day, but the RAIB report is highly unlikely to be widely read by the general public (and Lumo’s customers). It was an attempt to protect their reputation

The same thing as happened after the sa;lisbury derailment. A lot of misinformation got out and will be remebered by many more people than will ever read the official report, when it eventually comes out.

"A lie can travel half way round the world befoire the truth can get its boots on"

Highly relevant to politics as well, as I have discovered while canvassing for the local elections.

 

[TheBigD]

Can’t wrap my head around why the driver would ignore the flashing yellows unless he had a death wish. Can only assume he thought the turn off was 75 instead of 25.

As I understand it, it wouldn't have received any flashing yellows as the diverging route wasnt set as it was following the EMR service ahead which was then crossing over at 15mph to platforms 4/5/6/7. Once the EMR had cleared the junction, the route was then set for the Lumo service which was by then approaching P468 at red, subsequently changing to green with a route indication for the up slow/platform 1.

As before, happy to be corrected.

 

[Snow1964]

As I understand it, it wouldn't have received any flashing yellows as the diverging route wasnt set as it was following the EMR service ahead which was then crossing over at 15mph to platforms 4/5/6/7. Once the EMR had cleared the junction, the route was then set for the Lumo service which was by then approaching P468 at red, subsequently changing to green with a route indication for the up slow/platform 1.

As before, happy to be corrected.

So just to be clear, are there different diverging speeds, a 15mph route the EMR train took, a 25mph route that the Lumo train was signalled through, and a faster route which the green signal normally shows.

So could it be that driver hadn’t been routed down that specific track for long time, and simply forgot (or thought it was different having mixed it up with another location) and thought crossover was nearer 75mph than 25mph, only realising at last moment that it was slower when he/she saw the speed limit sign

Was the Lumo train going much slower approaching the previous signal, which then became less restrictive once the EMR train had cleared the junction. Having a quick accelerating train was it simply a case of having slowed by approach control, increased the speed too much after seeing the green.

 

[ComUtoR]

Once the EMR had cleared the junction, the route was then set for the Lumo service which was by then approaching P468 at red, subsequently changing to green with a route indication for the up slow/platform 1.

How fast do their units accelerate ?

If the Driver was approaching a Red then needed to accelerate, then that's pretty impressive to then hit the points so fast. Is it a long signal section ?