Who would like to see new class of tubes?

[audigex]

Indeed - there's a reason "it was like being hit by a train" is used as a comparison.

[John]

I was thinking more along lines of suicide pits, platforms sloping away from edges, platform doors, increased clearance between train equipment and track bed, and front-end design of trains. The HST front springs to mind as one that seems to do particularly badly in train vs. car/truck incidents.

[EXTspotter]

Or train vs. tree as was shown not too long ago. The problem in using the HST as an example of a bad design is not clear as by using examples such as Ufton Nervet, 2004, the train was doing approximately 100mph, hence as well as travelling much faster than say the 156, it is much heavier, therefore it has more energy which is dissapated in the crash. Using a similar idea the 91 and Mk4 DVT could be a bad design due to the Selby rail crash which occured at 88mph (142mph if you include the closing speed of the class 66 which it also collided with).
At the same time could the 158 been seen as being a good design in terms of front end collisions after the one which crashed into a bridge at Barrow upon Soar.


*Grumbled musings*

[John]

Except in both Ufton Nervet and Selby, both leading bogies derailed, and upon reaching a set of points disaster struck.

I can't help but feel that the design of the front of the HST makes this a more likely event.

[EXTspotter]

Why? Because the nose shape could lead to something it hits being "funnelled" under the front of the train in a way that a flat fronted train wouldn't?

[JamieLei]

How would a 150 compare, seeming as they're fitted with scoops on the bottom? Presumably better than tube stock which would expose someone to the workings instantly...

[John]

Why? Because the nose shape could lead to something it hits being "funnelled" under the front of the train in a way that a flat fronted train wouldn't?

More that as a result of the nose leaves very little structure actually in front of the leading bogie.

No idea how much extra the nose pushes stuff down at a high speed collision - but compare the metalwork directly infront of the leading bogie on an HST and the Eurostar. Eurostar has perhaps 3x more, and the Javelin twice more (alright, I'm comparing lengths of bodyshell which doesn't correspond to amounts of metal, but given that both Eurostar and Javelin have couplers, its going to be a lot stronger then the HST, which at a guess is mostly plastic?)

How would a 150 compare, seeming as they're fitted with scoops on the bottom? Presumably better than tube stock which would expose someone to the workings instantly...

That's the point I'm after - is there actually any research that has looked into this?

If the tube train has bigger clearance underneath, so that it passes over you if you're lying between the rails, but the scoop doesn't....

[andel]

Except in both Ufton Nervet and Selby, both leading bogies derailed, and upon reaching a set of points disaster struck.

I can't help but feel that the design of the front of the HST makes this a more likely event.

I hate to tell you this, but the speed of those collisions played a part. The shape of the train is nothing to do with the actual impact, but its the protection afforded to the driver that matters - a 380 is a lot more safer for a driver than a 360 because of the crumple zone built in. Other incidents where a train has derailed include where the 170 in Norfolk hit a piece of level crossing rubber. The weight of an hst vs a 158 is a difference of just two ton per axel.

[Kevo00]

Going back to the runaway train - a control room video has appeared on the BBC website! http://www.bbc.co.uk/news/uk-england-london-11016085

[Chris]

Interesting.

[Dave]

Probably, a staff member has rerun the moment, as you can do with the LU signalling machines.

Still, very interesting. Kentish Town's so odd haha.

[Kevo00]

The Camden-Euston bit is most interesting though, as the lines acutally loop over each other and approach Camden Town on different sides to those shown on the tube map.

[audigex]

I highly doubt the design of the train makes much difference other than the basic structural strength. If you hit something hard enough, either the front end is going to be deflected, causeing a derailment, or the front end is going to stick, the train will jack-knife and the rear will be forced off the track. It's very rare you get a train impact where there's no derailment at line speed.

Flat fronted, sloped in any particular direction isn't going to make much difference other than the direction in which the derailment occurs: extra metal in front of the bogie won't help, because the structure is reasonably rigid, the carriage moves as one unit.

[Ploes]

Is there any crash testing done on trains?

Presumably nothing is done to the level of the Euro Ncap on cars, to trains? or am I wrong?

[EXTspotter]

In NCAP the (crash) testing itself needs the destruction of several vehicles. Which seeing the cost of a car isn't a massive amont. With trains, having to built a number of vehicles only to destroy them would be very costly. I do not know whether this type of safety testing is done on trains (at least to the level of cars) however if it was, surely we would have heard about it or seen footage ourselves before now. The only rail vehicle in the UK I recall being "tested" is the one for carrying radioactive materials which looks like a flatbed with a massive metal box ontop, which they staged a crash between one and a peak with a few coaches. Secondly after a crash, rather than reffering to the train's "safety test" as it were, they are compared to similar crashes or crashes involving the same train class. For exaple when a class 86 (could have been an 87) with Virgin WC crashed into a couple of pacers on an empty stock run, the supposed uncrashworthyness of the pacer had only been realised (by the media) at that point.

[Chris]

I do actually remember in a physics video, which was at least 30 years old, some crash testing on a class 37/40, don't really remember what it was, but it went into a brick wall.

[Dave]

There's no need for it really though, as crashes are rare.

[JamieLei]

The newer trains are very solidly strong. If the Grayrigg accident told us anything, it's that even upon a pretty drastic derailment, the integrity of the coaches were completely unscathed. Compare to previous derailments where the coaches literally bend into two, or telescope.

[Dave]

The newer trains are very solidly strong. If the Grayrigg accident told us anything, it's that even upon a pretty drastic derailment, the integrity of the coaches were completely unscathed. Compare to previous derailments where the coaches literally bend into two, or telescope.

They wouldn't telescope here though as the train was moving on open railway - you can't compare the mk3/4 coaches at (e.g.) Selby as they were involved in a head on collision. The Pendolino would have been exactly the same in that situation, although it would have been worse because there would be passengers in the leading coach. Almost all the serious injuries were caused by the collision with 66521.

Potters Bar incident was exacerbated by the station platforms, Ufton Nervet by points. The Pendolino here was very fortunate in that it didn't really hit an obstacle that caused a sudden stop, it just went into a muddy (and very soft grounded) field.

The crashworthiness is brilliant, but I'd want to see the Pendo or Voyager in a similar incident to that at Paddington, Clapham or Selby before passing judgement on the superiority of the Pendolino to the mk4 - and I'm not one who screams "proper traction" and gets very heated about "plastic".

Obviously, touch wood that won't happen - most accidents these days that ARE the fault of poor maintenance or whatever are generally minor. Much better than the regular accidents of 10-15 years ago.

[andel]

I do actually remember in a physics video, which was at least 30 years old, some crash testing on a class 37/40, don't really remember what it was, but it went into a brick wall.

Class 40 at Old Dalby.