Dutch train derails at Dalfsen

[PaulRhB]

Was the cab hit above the crash structure as this machine had a raised hydraulic boom? If the platform hit the front window and then caught in the pillars, dragging the machine as in one report, it might not have hit the crash structure as designed.

[Dagworth]

Cherry pickers are VERY heavy, they have to be to counter the moments of the arm at full stretch. I'm not surprised at all at the damage the collision caused to the unit.

I have a ticket to operate them. Even the small ones weigh a few tonnes

 

Andi

[PatB]

 

@Andi: whatever the weight, it's peanuts compared to a train. A basic 2 car NS EMU weighs in at 100 tons, I suspect the Stadler units to be around the 90 tons mark.

 

The weight of a concrete building block is also peanuts compared to the weight of a train. It will still go through the front of most cabins, the driver and the back of the cabin if hit at speed when scrotes drop it off an overbridge.

 

Smacking a telehandler/cherrypicker/whatever at 100 km/h is a pretty severe test for  any crash structure and, if anything, the weight (r, more correctly) mass of the train makes it even more severe. In a professional capacity I've seen plenty of videos of crash tests with laden trucks (road vehicles) and every single one has emphasised that, in any collision, the place where you don't want to be is at the pointy end with lots of mass behind you.

 

That is not to say that the driver protection of  the units involved in this case could not be improved, but I think you're underestimating the reasonably predictable consequences of a collision of this nature. 

[PaulRhB]

I'm just trying to show until there's more info on this there's still a lot of reasons the cab could have been destroyed yet the rest seems to have done remarkably well in protecting people. No doubt the company and drivers representatives will look very closely at this once the report is out.

The HST that hit a car at a level crossing here did very well structure wise until the point beyond the crossing flipped it and the top half of the cab took the impact forces and the window failed. The tree at Lavington although it badly damaged the cab showed just how strong they are as it stopped it completely cutting through. You can't predict every possibility of where the heaviest impact is as the item can flip up due to external factors or have a higher than average structure as is possible here. While this is undoubtedly tragic for the driver I'm wondering how many were in the coaches flipped on their side as there's been little focus on that and how they fared. I hope it will be possible to get a summary of the report eventually as there may be some positive performance there too.

Having current experience of risks and the assessments at problem crossings I'm always surprised and saddened how supposedly intelligent people treat the signs and their lives because they are in a hurry or a bad mood so there's a lot to come from this investigation.

[meil]

Dutch Law is considerably different from British (-based) law, so don't judge our system through foreign eyes : ,

Not so different. We are both subject to the The European Framework Directive on Safety and Health at Work (Directive 89/391 EEC)

[jjb1970]

One of the oft quoted advantages of articulation is that it improves safety in the event of a crash which results in a derailment by holding vehicles together and keeping them upright.

I must admit, I do wonder if the structural crashworthiness of some types of rail vehicle peaked in the 70's and 80's as I've seen a few accidents over the years where the vehicles seemed to deform and suffer a lot of damage in a way which appears worse than for example a Mk.3 coach.

[Jim Martin]

 

there's room for varying interpretation of the rules, as always with EU directives And Dutch law-makers quite frequently interpret those differently then their counterparts in London, Paris and Berlin

That's the difference between a directive and a regulation. A regulation is a law, while a directive sets out a desired result while leaving it up to individual states how they actually achieve it.

 

When I was learning about this, the example we were given was a theoretical directive to reduce population by a certain amount. A state could opt to enforce some kind of "one chid" policy, or it could cull everybody over a certain age, or something else.

 

Jim

[Edwin_m]

I must admit, I do wonder if the structural crashworthiness of some types of rail vehicle peaked in the 70's and 80's as I've seen a few accidents over the years where the vehicles seemed to deform and suffer a lot of damage in a way which appears worse than for example a Mk.3 coach.

That's because they are designed to do that.  Modern rolling stock includes a so-called "crumple zone" which deforms and absorbs energy which would otherwise have to be dissipated in some other way.  By doing so they should minimise damage to the passenger areas and driver's cab. Older vehicles such as the Mk3 were designed to remain as far as possible structurally rigid. 

 

Having said that it is questionable whether this approach is worthwhile considering the extra cost and loss of useful space against the fact that accidents are relatively rare and in many accidents deformable zones will make no difference (as at Lambrigg according to the RAIB report, the only major accident to UK rolling stock having deformable zones).  However a level crossing collision with something larger than a car is probably one instance where a deformable nose structure could make a difference to the outcome. 

[Andrea506]

Having ridden on a few GTW units they do seem to essentially be a lightweight passenger coach articulated with a heavier drive module. They sound similar to riding a modern tram. I guess in all train design you have to compromise between weight and solidity. Or should they be built "American style"? I heard that in Los Angeles running trains as push/pulls is being frowned on due to a couple of level crossing collisions recenty.

[stewartingram]

This takes me back to the 60s when I lived in Cambridge. The local paper quite often had an input from a local guy who didn't like the trend in car design (of that era). He proposed that every car should have a pointed nose rather than a crumple zone. He went as far as modifying a number of his cars (and featuring them in the paper). His theory was that a pointed car would be very unlikely to hit another one exactly head on at the point, they would both deflect off one another on the sloped bits.

 

Stewart

[Kenton]

 

His theory was that a pointed car would be very unlikely to hit another one exactly head on at the point, they would both deflect off one another on the sloped bits.

 

 

 

OT. But essentially rolling them over on to their flat roof. Been there done that, give me crumple zones every time everything to maintain the integrity of the compartment one travels in. Even if you deflect from one object it isn't going to "deflect" from a sold wall or a tree/lamp post.

[PhilJ W]

This takes me back to the 60s when I lived in Cambridge. The local paper quite often had an input from a local guy who didn't like the trend in car design (of that era). He proposed that every car should have a pointed nose rather than a crumple zone. He went as far as modifying a number of his cars (and featuring them in the paper). His theory was that a pointed car would be very unlikely to hit another one exactly head on at the point, they would both deflect off one another on the sloped bits.

 

Stewart

Not so good for pedestrians and cyclists though.

[Glorious NSE]

Not so good for pedestrians and cyclists though.

 

Or whoever had the lower nose, and ends up with the other car on top of them...

[Edwin_m]

Or if the impact is anything other than head-on.  To deflect the other vehicle, the pointed nose would have to be very solidly built, rather like a battering ram in fact. 

[stewartingram]

I was only reporting what was in the paper!

 

Stewart

[Talltim]

From this pic it looks like the boom was extended a long way, but the accident may have done that