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LNER empty trains collided, service disruptions expected

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I don't see that the sort of damage mentioned is a safety concern as a passenger. After all, the more the impact is spread around the train, the less it it will effect the occupants. The sideways movements is more of a worry as it potentially puts the train in the path of others.

However from a financial point of view it is extremely worrying. We all end up paying, both in actually money and in interuption to service.

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1 hour ago, chris p bacon said:

 

If the damage is as severe as suggested then how or why did it move under its own power on the network only a week or so ago.

 

 

We've moved things in the past in a far more damaged condition than that - obviously at low speed and when not presenting a hazard to anything else gauge or derailment risk wise.  But, as Jim has already said, it is important to know the provenance of the information Ken reported (no doubt in good faith).  I have heard from another source information about the collision which did not surprise me (it seemed to me to be consistent with the outcome)  so it is no surprise that information might have leaked out.

 

The wider political  (note the small 'p') situation could well be a difficult one because we could have in effect one part of a Govt department (albeit 'functionally independent') investigating what amounts to decisions made by another part of the same Dept and involving a massive contract and so on. There might will be a need for 'some very careful handling of information'  emerging about damage to this type of train if it results in egg on certain faces.  Thus, again as Jim has already said, the original provenance of what Ken has reported assumes considerable importance and It might even call into question the extent of computer modelling of crash resistance during the specification and design phases - we don't know.

 

 

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1 hour ago, SHMD said:

If (ok a big if) that unit is a write off, why not crash test the other (good?) end to record the various dynamics at play here?

 

 

Kev.

Fair comment (from a scientific/investigative point), but where would you crash it and into what? 

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Just now, iands said:

Fair comment (from a scientific/investigative point), but where would you crash it and into what? 

Anyone got a spare nuclear flask lying handy?:)

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2 hours ago, SHMD said:

If (ok a big if) that unit is a write off, why not crash test the other (good?) end to record the various dynamics at play here?

 

 

Kev.

Surely if the whole unit is a write off there isn't a 'good' end?

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23 minutes ago, Talltim said:

Surely if the whole unit is a write off there isn't a 'good' end?

Guess it depends just how extensive the damage is. Not something people should be travelling in might still be of use for some tests.

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I can’t see the unit being written off and after talking to a LNER driver yesterday, the damage isn’t as bad as first thought.  If there had been any serious concerns, the unit would have been moved to Doncaster by road instead of allowing it to move by rail, even if it’s slow speed or on a wheel skate.

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3 hours ago, Talltim said:

I don't see that the sort of damage mentioned is a safety concern as a passenger. After all, the more the impact is spread around the train, the less it it will effect the occupants. The sideways movements is more of a worry as it potentially puts the train in the path of others.

However from a financial point of view it is extremely worrying. We all end up paying, both in actually money and in interuption to service.

It should always be remembered that once any part of it is derailed, a moving train is an uncontrolled missile. How it behaves and where it ends up depend on many largely unpredictable factors working in concert, with a large element of chance involved. The Great Heck derailment, for example, was not in itself particularly serious. What turned it into a serious incident was the unfortunate presence of a train passing in the opposite direction at just the wrong moment. Ditto. Clapham Junction and Potters Bar, where the unfortunate element was an overhead line pole in the path of one carriage.

 

Jim

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28 minutes ago, jim.snowdon said:

It should always be remembered that once any part of it is derailed, a moving train is an uncontrolled missile. How it behaves and where it ends up depend on many largely unpredictable factors working in concert, with a large element of chance involved. The Great Heck derailment, for example, was not in itself particularly serious. What turned it into a serious incident was the unfortunate presence of a train passing in the opposite direction at just the wrong moment. Ditto. Clapham Junction and Potters Bar, where the unfortunate element was an overhead line pole in the path of one carriage.

Conversely I suppose there was an element of good chance involved at Grayrigg, where it didn't hit anything particularly solid (although at 90 mph I'd have thought it rather unlikely it could've gone down the embankment yet avoided an overhead line pole).

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I'm sure a lot of mathematical structure related design was put into the 800 especially in the area of safety. Perhaps a small degree of twisting crumpling etc was to be expected, I don't know. Modern structures (cars, planes trains) are designed to withstand high loads / impacts. - both cars and aircraft structures often tested to destruction, as in this Boeing 777 wing deformation test, which was designed for a hoped for failure at 150% of max estimated load, actually failed at 154% as per this test - a pass.

 

 

Impact protection test for a "spare" car from the unit involved ? Perhaps would either prove the design or fail it. Not being a structures engineer I don't know.

 

By the way the leading HST train was travelling at around 5 mph (8 km/h) and the colliding 800 train at around 14 mph (22 km/h). The resultant collision speed  therefore = 9 mph (from the interim report below). Not very high. Would normal buffers have absorbed this ?.

 

https://www.gov.uk/government/news/train-collision-at-neville-hill

 

Brit15

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I assume that like all modern trains, the 8xxs have vehicles of integral construction. Cars have been like that for many decades - and the slightest crease in the roof of a car otherwise repairable is enough to condemn it. Is the same true here?

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4 hours ago, SHMD said:

If (ok a big if) that unit is a write off, why not crash test the other (good?) end to record the various dynamics at play here?

 

Because without a complete trainset you don't get valid results - you don't have the extra mass behind pushing and reacting to whatever test you decide to implement.

 

For example, you could have tested a 800 cab car crashing into an HST power car and decided great, everything is fine, the noise takes the damage - but you wouldn't have gotten what we saw where a low speed collision resulted in intermediate carriages going sideways at one end.

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7 hours ago, APOLLO said:

800 written off in a  (approx) 15 mph head on with a HST (with its crumpable front end)  - Simply unbelievable and VERY worrying. Are the coach shells themselves write offs or just a number of replaceable components ?

 

As the HST was moving in the same direction at 5mph, actually only a 9mph collision (From the RAIB statement). It also means it didn't hit a stationary or 'solid' obstruction - Such as a train standing with it's brakes on, or buffer stops.

Yes, from what I was told it's the coach bodies, bogies, running gear, and couplings. Power, traction equipment, and interiors etc to be striped out, transported back, and used to fit out the new set.

Apparently, they're going to Wolverton to be stripped / scrapped so as not to interfere with ongoing construction.

 

7 hours ago, jim.snowdon said:

I think that first, I should want to know the authenticity of the information to start with. Not what Ken.W said, but where the information he was given originated.

NR would probably also have insisted that the carriages went off the network on the back of lorries and not on their rails at all.

 

Well yes, after 42 years service I'm well aware to be dubious of depot gossip.

This did however come from an LNER driver I know to be trustworthy not to embellish things, and who had himself been talking directly with someone... somewhat much more senior

(Sorry but can't say more in public)

 

The movement was made overnight and at very low speed so as not to present a risk. Use of a wheelskate would mean a restriction, IIRC, of something like 15mph on plain line and 5mph through points and crossings.

 

6 hours ago, chris p bacon said:

If the damage is as severe as suggested then how or why did it move under its own power on the network only a week or so ago.

 

As above, and I should add that they're going to Wolverton by road.

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58 minutes ago, Oldddudders said:

I assume that like all modern trains, the 8xxs have vehicles of integral construction. Cars have been like that for many decades - and the slightest crease in the roof of a car otherwise repairable is enough to condemn it. Is the same true here?

 

Many years ago one of our Leyland Nationals was hit on the rear offside top corner by a luton van whilst stopped at a bus stop. The damage appeared to be just on that corner, but after driving it into the garage I found that the drivers access door would not close properly.

 

We did some measurements and found the off side top member had been pushed forward by 1 ½ inches. The vehicle was deemed a write off.

 

This happened because of the shock wave passing along the integral structure.

 

On any other bus or coach with a separate chassis and body, the damage would be confined to just the impact point and a day with some sheet metal and fibreglass would have it repaired.

 

Peter

 

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What I find disturbing is that it was not just the front car, it seems several cars affected, the impact shock went through the entire train,. Buffers, or at least some shock absorbing coupling system would have helped to absorb the impact.

 

They certainly don't build them like these anymore !!

 

 

 

 

Then there are these crazy ************* - This train "seems" OK

 

 

The ultimate hard coupling - watch the second & third loco's frame flex - no problem - couple up & good to go - built like a brick sh1thouse !!

 

 

800's - tinfoil trains - melt em down quick for Christmas turkey roasting trays !!

 

Brit15

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45 minutes ago, APOLLO said:

What I find disturbing is that it was not just the front car, it seems several cars affected, the impact shock went through the entire train,. Buffers, or at least some shock absorbing coupling system would have helped to absorb the impact.

 

They certainly don't build them like these anymore !!

 

Brit15

Perhaps you should have a read of this.

 

http://www.railwaysarchive.co.uk/documents/MoT_Etterby1952.pdf

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Final paragraph of the above report

 

22. In conclusion, I would draw attention to the effect of the central Buckeye couplings and robust Pullman gangways in distributing quite a violent shock throughout the Stranraer train without severe damage to any one vehicle. As has been mentioned in previous reports, this equipment has been standardised for new carriage construction on British Railways.

 

Brit15

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So buckeyes have always helped practical safety in overtaking accidents. Given that the 8xx vehicles are 26 metres in length, nearly one-third longer than the typical 20 metre length of most Big 4 and earlier BR coaches, we can understand why an alternative connecting mechanism within set was needed having regard to end-throw etc, but prima facie there may be a downside. All this must surely come out in the wash currently in the investigation machine. 

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50 minutes ago, APOLLO said:

Final paragraph of the above report

 

22. In conclusion, I would draw attention to the effect of the central Buckeye couplings and robust Pullman gangways in distributing quite a violent shock throughout the Stranraer train without severe damage to any one vehicle. As has been mentioned in previous reports, this equipment has been standardised for new carriage construction on British Railways.

 

Brit15

Yes, but the damage was distributed throughout the entire ten coach length of the train, not just the last coach, with underframe damage to the first, second, eighth and tenth vehicles. The light engine was only 161 tons, although its speed was higher.

 

Structural damage to the entire train occurred even then.

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Newtons laws of physics in action.

 

I wonder how the Mk 3's in the HST fared ?

 

Brit15

 

 

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If the unit is written off, there are going to be some very red faces at Hitachi as to why the whole set was not able to withstand a slow speed collision.  Also I expect there’s going to some very angry faces at the DfT asking the very same question and also questioning the whole IET crashworthiness.

 

If the leading coach is written off, with the production line still going, surely a replacement can be built and parts off the damaged vehicle put onto it’s replacement?

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18 minutes ago, APOLLO said:

Newtons laws of physics in action.

 

I wonder how the Mk 3's in the HST fared ?

 

Brit15

 

 

I jest in a way, however probably there was some dust expelled from nooks and crannies and maybe a toilet seat was dislodged from the upright catch.

Phil

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One thing that should be remembered is that at this point in time the threshold value of what constitutes a write off will be much lower than what it would be in say 5 years time when the 800's are no longer in production. Any damage now which would be more difficult to fix than just simply adding a couple of extra bodyshells to the production run and swapping parts over will be a write off.  When the only option is fix it or do without then the threshold for economic repair will be a lot higher.  66734 was a brand new loco, and was scarcely damaged in it's derailment, but it was deemed more economical to order a new one and dismantle it on site rather than recover it. Incidentally about 85% of components were recovered for further use.

 

Similarly with the class 47's. 512 built, but never more than 510 extant at any one time.  One can't help thinking that a total of 510 were desired, plus two extra to cover those written off in accidents, which might otherwise have been repaired had 47's not still been rolling off the production line.

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31 minutes ago, jools1959 said:

If the unit is written off, there are going to be some very red faces at Hitachi as to why the whole set was not able to withstand a slow speed collision.  Also I expect there’s going to some very angry faces at the DfT asking the very same question and also questioning the whole IET crashworthiness.

 

If the leading coach is written off, with the production line still going, surely a replacement can be built and parts off the damaged vehicle put onto it’s replacement?

 

This is hardly a retrograde step (and it's not like you could blame Hitachi as they merely designed to project specifications), apart from shock wagons in the UK and cushion coupler pockets in the US the reliance for slow speed impact damage has been with buffers on stock, and that can only really survive slow speed contact with limited energy such as at a hump marshalling yard. 

 

Anti climbers and crumple zones are only really for higher speed collisions, and although you could build trains with big rubber bumpers that could survive slow speed impacts, it would be better to stop them occuring in the first place. 

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So, after all this surmising, has anyone with some sort of higher knowledge of Physics and engineering, had a go at calculating what they think might happen at 140mph with one of these things if it hits another fairly solid object either whilst still on the track (as at Heck), or when in flight having departed the track in some way? Me being ignorant is bloody worried at the thought of what I think will happen. 

P

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