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LNER empty trains collided, service disruptions expected


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Modelling only half a coach as its symmetrical in one of the Hitachi crash models without an obvious assessment of the restraint conditions is a potentially basic error. When I took over the development of the assessment model of the Forth bridge in 95 I redid the support calculations in all six degrees of freedoms of the suspended spans for the same reason.

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I've just read the report in full and as usual in these cases it makes very interesting reading. Quite a few questions for LNER to answer re their driver supervision.  Also some seemingly serious design problems with the TMS in terms of driver distraction leading to information  overload.  This has been a problem in the aviation industry for a long time.  However the derailment risk is a difficult one and seems to go right back to the decision to go to 26m coaches. I wonder if that will come back to bite the Dft who specced the train.

 

Jamie

 

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1 hour ago, jamie92208 said:

  However the derailment risk is a difficult one and seems to go right back to the decision to go to 26m coaches. I wonder if that will come back to bite the Dft who specced the train.

 

 

 

Probably not - its worth remembering 26m vehicles have been used extensively in continental Europe with no issues.

 

If anything the RAIB are actually pointing the finger at those in charge of the relevant EU safety standard which seems to ignore any collision below 22mph. Although understandable in some respects (a under 22mph collision is unlikely to be that harmful to on board passengers) the failure to consider the potential to obstruct adjacent lines is a significant one in an age where H&s is superposed to be of such importance.  That omission will have in turn had implications for the design stage of the IET and is not really Hitachi's fault.

 

Edited by phil-b259
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1 hour ago, phil-b259 said:

If anything the RAIB are actually pointing the finger at those in charge of the relevant EU safety standard which seems to ignore any collision below 22mph. Although understandable in some respects (a under 22mph collision is unlikely to be that harmful to on board passengers)

Really? The accident at Cannon St in 1991 seems to have occurred at about half that speed, and while of much older rolling stock, the capacity to throw people about resulted in two fatalities and 547 injured. 

 

https://www.railwaysarchive.co.uk/documents/HSE_Cannon1991.pdf

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13 minutes ago, Oldddudders said:

Really? The accident at Cannon St in 1991 seems to have occurred at about half that speed, and while of much older rolling stock, the capacity to throw people about resulted in two fatalities and 547 injured. 

 

https://www.railwaysarchive.co.uk/documents/HSE_Cannon1991.pdf

 

 

If low speed impacts are that catastrophic please explain why the EU standards governing what happens in collisions do not apply below 20mph / 36mph. That figure (and the decision to exclude lower speeds) must have been decided on by someone.

 

The logical deduction is that at sub 22mph speeds the chances of serious injury or death in a modern train* (NOT one built in the 1950s** with all the problems that brings) will be near zero.

 

What appears to have been missed in this is the possibility of derailment and fouling adjacent lines - THAT is what the RAIB are more concerned about and which could have been anticipated had collisions speeds below 22mph been required to be considered in the design process

 

 

* with collapseable energy absorbing couplers, monocoque bodyshells, and interior fittings designed not to injure passengers, etc

 

** featuring separate underframes, flimsy bodyshells, non energy absorbing couplers, sharp interior fittings, etc

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5 minutes ago, Oldddudders said:

Really? The accident at Cannon St in 1991 seems to have occurred at about half that speed, and while of much older rolling stock, the capacity to throw people about resulted in two fatalities and 547 injured. 

 

https://www.railwaysarchive.co.uk/documents/HSE_Cannon1991.pdf

Hi Dudders,

 

I repaired 45407 after it collided with eight Mk1's at Rawtenstall at about 5 MPH. Bent frames, a cracked buffer stock, new buffer beam, buffer gussets, drag box and partial new frame stretcher, what a mess !

 

The train that was held on chamber side and also held on the guards brake while the locomotive ran around its train was shunted eight feet by the collision. Damage to the coach that was hit was smashed buffers and collars and a new corridor connection.

 

The main reason that on one on the train was injured was those that were still on the train were sat down, should any one been standing it may well have been different.

 

Gibbo.

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1 minute ago, phil-b259 said:

If low speed impacts are that catastrophic please explain why the EU standards governing what happens in collisions do not apply below 20mph / 36mph. That figure (and the decision to exclude lower speeds) must have been decided on by someone.

 

The logical deduction is that at sub 22mph speeds the chances of serious injury or death in a modern train (NOT one built in the 1950s with all the problems that brings) will be near zero.

Why would I be able, still less want, to explain an EU standard?

 

The problem that Cannon St demonstrated was that human beings do not respond well to sudden deceleration at 10-12 mph, the estimated speed from several witnesses. Double that and things do not improve. 

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11 minutes ago, Oldddudders said:

Why would I be able, still less want, to explain an EU standard?

 

The problem that Cannon St demonstrated was that human beings do not respond well to sudden deceleration at 10-12 mph, the estimated speed from several witnesses. Double that and things do not improve. 

 

The point is there would no doubt have been a large number of people in drawing up said regulation and there must be rationale in fixing 22mph / 36kmh as the point below which it can be disregarded. If low speed collisions were thought to be that catastrophic then I refuse to believe that such a threshold would have made it through the process without adjustment.

 

Yes, its well known that sudden decelerations are not good for the human body - internal organs will slam into the skeleton etc and can cause internal injuries. However you cannot ignore the fact that a deceleration from 40mph to zero is going to be much worse than 20mph to zero and that will be reflected in KSI statistics.

 

However, as I said above its not the collision speed that the RAIB are really interested in. My reading of the report is they are more interested in the mechanism by which the train became foul of an adjacent line when modelling showed that this would not happen in a higher speed collision, plus driver training issues. The performance of the rolling stock in terms of potential harm to passengers contained within seems to be a non issue for them.

 

 

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1 hour ago, Oldddudders said:

Really? The accident at Cannon St in 1991 seems to have occurred at about half that speed, and while of much older rolling stock, the capacity to throw people about resulted in two fatalities and 547 injured. 

 

https://www.railwaysarchive.co.uk/documents/HSE_Cannon1991.pdf

I think Cannon Street 1991 was an extreme example, in terms of the specific conditions causing so many injuries.

  • A huge proportion of the passengers were standing up ready to get off.  Plenty would have been picking their briefcases etc off the luggage racks, when knocked off their feet they may have hit someone with them.  Being hit by a briefcase at 10mph could break bones (these day far more people are carrying soft luggage like rucksacks).
  • A lot of the slam doors were already opened by passengers so that they could leap off before the train stopped (and be quickly through the ticket barriers - idiots).  This removed much of the ability for the body sides to absorb any end load.
  • Some carriages started to climb over the one in front, causing crush injuries.
  • In Mk1 design stock, seat corners, luggage racks, door and window frames were solid wood or aluminum.  Nowadays they are "softened" with plastic overlays or hollow.  This massively reduces the decelleration forces on the body to the extent where instead of breaking a bone, you get a small bruise.

The Cannon St. crash was one of the major contributors to Mk1 slam-door stock being phased out by law, although it took nearly 15 years.  One thing I do remember was the Fleet St. press claiming they'd uncovered the "secret" that the EPB stock had been re-built on former Southern EMU underframes, as if their age was a contributory factor and the government had been scammed.  Any vaguely knowledgeable spotter at the end of the platform that day could have told them that secret.

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51 minutes ago, Northmoor said:

.  One thing I do remember was the Fleet St. press claiming they'd uncovered the "secret" that the EPB stock had been re-built on former Southern EMU underframes, as if their age was a contributory factor and the government had been scammed.  Any vaguely knowledgeable spotter at the end of the platform that day could have told them that secret.

 

Some of them were running on LB&SCR underframes and bogies which had been rebuilt by the Southern in to EMU's, and rebuilt again by BR into EPB's...

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1 hour ago, Titan said:

 

Some of them were running on LB&SCR underframes and bogies which had been rebuilt by the Southern in to EMU's, and rebuilt again by BR into EPB's...

 

I don't think so.

 

My understanding was the pre-grouping units got scrapped - its the 1940s new build Augmentation trailers and EMUs which got their underframes recycled as they were not yet two decades old by the time the EPB programme got up and running.

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It is an interesting report and as others have said a whole series of unrelated concerns. 

 

However, as a mere customer, I must say that the industry ignoring the effect of lower speed shunts is worrying. OK so the interiors have been softened. But, these are not aircraft where everyone is required to stay seated and locked down until the plane has come to a standstill. Instead my experience is that a high proportion of passengers on the ECML begin to get ready to get up as they pass Emirates stadium. Speed can still be quite high (my experience is only on HST and 91s). So most are on their feet, getting bags down - including heavy ones from the end racks or between the seats. Maybe things are better than on an EPB but it does seem incredible that the risk assessments have just ignored the possibility of a total stop from what is a reasonable speed - 22mph isn't slow!

 

Paul

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2 hours ago, phil-b259 said:

 

I don't think so.

 

My understanding was the pre-grouping units got scrapped - its the 1940s new build Augmentation trailers and EMUs which got their underframes recycled as they were not yet two decades old by the time the EPB programme got up and running.

 

Well put it this way, when I was working on them in the 90's there were many with "S.R." cast on to the axleboxes, but also more than a few with "LB&SCR" cast on them.  Now I suppose it could just have been just the axlebox covers that were re-used, but then when a coach has a complete set of axleboxes with LB&SCR cast on them I suspect it was a lot more than just the covers...

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9 hours ago, Titan said:

 

Well put it this way, when I was working on them in the 90's there were many with "S.R." cast on to the axleboxes, but also more than a few with "LB&SCR" cast on them.  Now I suppose it could just have been just the axlebox covers that were re-used, but then when a coach has a complete set of axleboxes with LB&SCR cast on them I suspect it was a lot more than just the covers...

Definitely just the axle box covers and even those were probably brand new from stock when first used on an SR underframe. The ex-LBSCR underframes used under (rebuilt LBSCR) electric stock were non-standard length and the last in use, under reformed 4-SUB units in the 45xx series, were withdrawn in 1960; the reformed interim units having been created precisely because their underframes were unusable under EPBs and yet had sufficient life to provide a necessary buffer while other older vehicles were withdrawn to enable their standard SR underframes  to be reused under EPBs.

 

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14 hours ago, hmrspaul said:

Instead my experience is that a high proportion of passengers on the ECML begin to get ready to get up as they pass Emirates stadium. Speed can still be quite high (my experience is only on HST and 91s). So most are on their feet, getting bags down - including heavy ones from the end racks or between the seats.

 

Fair point, but on the approach to buffer stops at a terminus such as Kings Cross speed will be controlled by TPWS, so the risk is minimised. 

 

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On 20/11/2020 at 12:50, caradoc said:

 

Fair point, but on the approach to buffer stops at a terminus such as Kings Cross speed will be controlled by TPWS, so the risk is minimised. 

 

I wasn't thinking about a controlled stop at buffers but an accident as it is an accident we are discussing. 

 

Paul

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6 hours ago, hmrspaul said:

I wasn't thinking about a controlled stop at buffers but an accident as it is an accident we are discussing. 

 

Paul

 

Fair enough, but I took it from the specific reference to passengers standing up on the approach to a terminus that you were referring to a buffer stop collision; Which would bring a train to a very sudden stop just as any other type of accident.

 

 

 

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36km/h is 10m/s and quite likely chosen as an arbitrary figure because it is a convenient number and of course all calculations are done in SI units. Whether there is justification in adopting 10m/s as opposed to 8.75 or 11.32m/s (for example) is open to conjecture. Somewhere in the minutes of the meetings of the drafting committee there will be a rationale.

 

As pointed out by phil-b259, of more interest is the derailment behaviour of the IET as obviously becoming foul of an adjacent running line holds the possibility of a high speed collision occurring.

 

I am presently involved with the safety assessment of a new Asian metro system and here the collision requirements go beyond those specified in the European TSI and supporting norms. In the EU such an approach is not possible for main line railways as compliance with TSI's and supporting norms as judged via the Common Safety Method is the only acceptable legal method of specification and review. It will be interesting to see if after 1st January UK deviates in the face of identified deficiencies in the standards. Requiring dynamic analysis of low speed collisions would seem a useful first step.

 

I am not knocking EU standards per se: they form a comprehensive interrelated coherent set that mostly do the job required.

 

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Does the EU Standard take the often tight UK six foot gauge into consideration when deciding that derailment deflection at low speed isn’t an issue? As a Pway man and having travelled extensively on European railways, something that is very noticeable is the generally very generous six foot gauge, when compared with the UK six foot.
 

But I feel sure that this couldn’t have been the case, as surely the modelling would have taken this into account and that at least one person of the many thousands involved in developing this standard would have noticed this difference. Tight six foots and vehicle behaviour during derailments is the first thing that comes into my mind when ‘one ends up in the dirt’. Is it fouling any other road? What roads need to be blocked? 
The damage to the cab was also not insignificant, although I’m sure that will be explained away. After all this is a train in public service, it has had XXXX spent on it already. The Emperor’s new clothes again??? We don’t want to panic the horses now do we.

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Once upon a time we had pullman gangways such that when the train was compredssed in a case like this the friction in the gangways provided very considerable damping to any tendency to sideways deflection. The modern coupler and gangway design is more inclined to magify such a tendency than restrict it. A read through the report does highlight some design issues, paritcularly the collapse strength of the coupling tubes, that could have helped but does not recommend changes. Probably because they could not take a view on the downside of any change. I was a bit surprised though that there was no recommendation to study the issue.

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On 23/11/2020 at 14:13, Grizz said:

Does the EU Standard take the often tight UK six foot gauge into consideration when deciding that derailment deflection at low speed isn’t an issue? As a Pway man and having travelled extensively on European railways, something that is very noticeable is the generally very generous six foot gauge, when compared with the UK six foot.
 

But I feel sure that this couldn’t have been the case, as surely the modelling would have taken this into account and that at least one person of the many thousands involved in developing this standard would have noticed this difference. Tight six foots and vehicle behaviour during derailments is the first thing that comes into my mind when ‘one ends up in the dirt’. Is it fouling any other road? What roads need to be blocked? 
The damage to the cab was also not insignificant, although I’m sure that will be explained away. After all this is a train in public service, it has had XXXX spent on it already. The Emperor’s new clothes again??? We don’t want to panic the horses now do we.

There is a presumption in the EU standards that railways were developed in accordance with UIC norms. For UK this is not correct and the major difference is of course the structure gauge. The TSI's note this and there is an exemption from compliance with normal gauging requirements for UK and Ireland contained in the TSI's. But, some things have been missed: the obvious example is electrification clearances where the TSI assumes compliance with the standard European structure gauge and cannot easily be achieved for UK infrastructure.

 

I cannot answer your question directly: you would need to find somebody on the drafting committee. I think the point is that the crashworthiness standard fails to consider adequately the possibility of large sideways deflections following a low speed shunt. For the reasons you describe, the consequences are potentially more severe in the UK.

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Harmonised European Standards have Characteristics (e.g. end loading) and Classes (a specific end load value). So in terms of collision speed if the class was indicated at 22mph then it would have to be safe at up to 22mph.  In terms of lateral deflection it would be up to the specifier to indicate a performance class relevant to their network. the question should be was the correct classes and characteristic specified in the IET procurement process. Given how bad the seat specification was I would not have high hopes.

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