Derailment Issues

[countryman]

Jan 30, 2020 19:00:52 GMT bassmike said:

Surprised that many more freight liner trains do not have derailment problems when you see long strings of unladen flats between loaded ones and very often flats with a container on one end only placed in the middle of unloaded units.

If you think that may be an issue, try watching the youtube videos of American freight trains. Many unloaded flats in the middle of huge 200 wagon trains on very badly maintained track, and generally they do OK

[bassmike]

I wouldn't say that. If you regularly watch U S rail videos there are constant derailments etc:

[cudsn15]

Why can't every wagon act as it's own set of scales - with it's own gauge? or just install these simple things with a human checker as each wagon is loaded: www.libraweighing.co.uk/train-weighers.html

[aslefshrugged]

Feb 1, 2020 9:42:57 GMT cudsn15 said:

Why can't every wagon act as it's own set of scales - with it's own gauge? or just install these simple things with a human checker as each wagon is loaded: www.libraweighing.co.uk/train-weighers.html

Money

[rincew1nd]

Feb 1, 2020 9:42:57 GMT cudsn15 said:

Why can't every wagon act as it's own set of scales - with it's own gauge? or just install these simple things with a human checker as each wagon is loaded: www.libraweighing.co.uk/train-weighers.html

Or, why don't those filling containers make accurate declarations about the weight of their contents? A recent MAIB report I read listed inaccurate container weight declarations as a contributing factor in the accident.

[cudsn15]

re- money - it's going to cost someone a damn sight more to fix this damage than the cost of weighing equipment! Could they even be insured for something like this?

[Chris M]

Yes this one accident will have cost more than fitting the wagons of this one train with weighing equipment (assuming the FOC is responsible for the whole cost). However, would the cost of fitting every wagon exceed the cost or all accidents that they would prevent? Is the organisation that will pay for the damage from this accent the same as the organisation that would pay for the weighing equipment?

[aslefshrugged]

Plus we have freight trains coming through the Channel Tunnel, would all those have to be self-weighing?

[class411]

As we've been asked to keep the Gobby line derailment thread on topic, I'm making this point here.

Someone suggested having each wagon with it's own weight measuring system, which was rejected by many on the grounds of cost - which seems reasonable.

Earlier in that thread I suggested that the rear of each goods train be fitted with a (or a pair) forward facing camera(s), transmitting images of the train to the cab.

This would not prevent derailment, but it would - provided that the driver paid attention - prevent a train with a derailed wagon or wagons from doing the amount of damage that has happened in this latest incident.

I'm pretty sure that the cost of such provision, even on a hundred trains - would be substantially less than the many millions it will cost to deal with this single incident.

[Colin]

I can't see that working.

Given the length of most goods trains, unless you are on a dead straight bit of track you won't be able to see the full length of a train.

And in any case, drivers need to be observing the road ahead for signals, obstructions, etc.

If you were to make a comparison with passenger trains and in cab monitors, these are only observed at low speed when moving off from a platform - not at speed between stations where signals can appear and disappear quickly or obstructions can appear that require an imediate reaction.

To introduce such a distraction into the cab, IMO would do more harm than good.

[Chris M]

The only way I could see this working would be for be for some automated real-time image comparison that sounds an alarm in the cab if the train becomes out of line. However, this would be very difficult and costly - for starters it would need several cameras given the length of the train, and need to distinguish between the subtle out of line derailment shapes from the vast number of shapes the train can have on variously curved track, especially when navigating point - when the train becomes significantly out of line the train generally doesn't get far as it becomes obvious in the cab that something is wrong (e.g. automatic brake application, very sharp increase in drag, etc). See for example the derailment at Eastleigh last week.

What might work better was some way of detecting electrical continuity between adjacent wheels other than through the vehicle frame. However, this would obviously require equipment at (approximately) every wheel so it would be costly. It would also need to not give alarms for rail gaps, insulated joints, etc. but somehow distinguish electrical conductivity due to the tread of the wheel running on the head of the rail and electrical continuity due to the side of the wheel running along the face of the rail (running rail or check rail).

Short of having multiple people distributed along the train constantly looking at the consist (very costly) this is not a problem with an easy solution.

[cudsn15]

aye - we'll never know. But if those track weigh scales can be fitted at key ports and terminations where these wagons regularly travel and they have an alarm that's triggered by an over weight load connected to the nearest signal controller that might be a solution perhaps? What I'm getting at is what can be done to prevent this from happening again...

Mind you looking at the state of some of the track in those network rail photo's maybe it was going to happen anyway - and also explains why speed limits are on this line - After all these years basic infrastructure renewal still isn't happening until a major event happens such as this - tho of course it will still be a patch and mend job.

[Chris M]

While overloading might have been a contributory factor to this derailment, it is unlikely to be the only cause (there has to be some reason why it derailed where it did rather than earlier in the journey) and it is not a factor that I can recall being mentioned in any of the RAIB reports into previous derailments. So while preventing it happening again is a obviously a good thing, focusing only on the weight of wagons is unlikely to achieve that aim, let alone at a cost proportionate to the problem.

[piccboy]

How about a system which senses unusual movement of any one (or more) wagons in a freight train? For example take sensors like an accelerometer (used in devices such as fit bits, and mobile phones), mount one (or more) on each engine and wagon in a train. As the train travels along, the accelerometers would naturally encounter some readings, but these would be in a logical order, i.e. the engine passes over a poor piece of track, then 1.5 seconds later wagon 1 registers the poor piece of track, 3 seconds later wagon 2 the same, 4.5 seconds later wagon 3 etc. However, if a wagon was to derail, the system would recognise this derailment because the readings from this wagon do not match others. Even if multiple wagons derailed, there would be a noticeable pattern to the derailment which does not match other wagons.

[d7666]

www.researchgate.net/publication/303027616_Derailment_Detection_and_Data_Collection_in_Freight_Trains_Based_on_a_Wireless_Sensor_Network

www.researchgate.net/publication/232829812_Study_on_detection_of_the_early_signs_of_derailment_for_railway_vehicles

These are 2 examples of research projects into exactly what the op is driving at.

You might not be able to get the whole of those papers, but the abstract is there.

So certainly your concept is right, and there is technical work in this direction.

Whether any of it will be cost effective is a whole different argument !!!


There is also this product from Knorr-Bremse

www.eka-knorr-bremse.com/en/_hidden/railvehicles/products/trainsafety/edt101.jsp


--
Nick

[crusty54]

Freight trains are not fixed formation.

[35b]

Feb 1, 2020 18:14:31 GMT Chris M said:

While overloading might have been a contributory factor to this derailment, it is unlikely to be the only cause (there has to be some reason why it derailed where it did rather than earlier in the journey) and it is not a factor that I can recall being mentioned in any of the RAIB reports into previous derailments. So while preventing it happening again is a obviously a good thing, focusing only on the weight of wagons is unlikely to achieve that aim, let alone at a cost proportionate to the problem.

All up weight hasn’t, but distribution within wagons and containers has - particularly in connection with either difficult track geometry (a couple of trains coming out of Angerstein wharf come to mind) or track twist.

I await the RAIB report.

[billbedford]

Feb 1, 2020 11:53:09 GMT rincew1nd said:

Feb 1, 2020 9:42:57 GMT cudsn15 said:

Why can't every wagon act as it's own set of scales - with it's own gauge? or just install these simple things with a human checker as each wagon is loaded: www.libraweighing.co.uk/train-weighers.html

Or, why don't those filling containers make accurate declarations about the weight of their contents? A recent MAIB report I read listed inaccurate container weight declarations as a contributing factor in the accident.

Weight? Weight? what's weight got to do with it? Look there's still plenty of space in this container...

[class411]

Feb 2, 2020 8:42:24 GMT billbedford said:

Feb 1, 2020 11:53:09 GMT rincew1nd said:

Or, why don't those filling containers make accurate declarations about the weight of their contents? A recent MAIB report I read listed inaccurate container weight declarations as a contributing factor in the accident.

Weight? Weight? what's weight got to do with it? Look there's still plenty of space in this container...

Many a true word!

[Chris M]

Feb 2, 2020 8:33:32 GMT 35b said:

Feb 1, 2020 18:14:31 GMT Chris M said:

While overloading might have been a contributory factor to this derailment, it is unlikely to be the only cause (there has to be some reason why it derailed where it did rather than earlier in the journey) and it is not a factor that I can recall being mentioned in any of the RAIB reports into previous derailments. So while preventing it happening again is a obviously a good thing, focusing only on the weight of wagons is unlikely to achieve that aim, let alone at a cost proportionate to the problem.

All up weight hasn’t, but distribution within wagons and containers has - particularly in connection with either difficult track geometry (a couple of trains coming out of Angerstein wharf come to mind) or track twist.

If you want to measure weight distribution then you need multiple measuring points (at least two, probably ideally 4) per wagon. That's not going to make it any cheaper.

[norbitonflyer]

Feb 1, 2020 12:24:22 GMT Chris M said:

However, would the cost of fitting every wagon exceed the cost or all accidents that they would prevent?

It wouldn't stop with fitting the weighing equipment to each wagon. Someone will have to maintain it and check it's correctly calibrated.

[d7666]

Feb 2, 2020 8:58:37 GMT class411 said:

Feb 2, 2020 8:42:24 GMT billbedford said:

Weight? Weight? what's weight got to do with it? Look there's still plenty of space in this container...

Many a true word!

Yet the capability to accurately load weigh every container is very easy to implement. Every container gets craned on to a wagon. Does not matter what shape of form that crane or other lift device is, that container is out on to a wagon. That device should load weigh the container and input to the train consist. It won't measure distribution of the load within the box though. Maybe this capability a!ready exists? I don't know, but I would have thought the crane operating companies would want to know what they lift every time for all sorts of reasons.

[norbitonflyer]

Feb 2, 2020 14:04:57 GMT d7666 said:

Yet the capability to accurately load weigh every container is very easy to implement. Every container gets craned on to a wagon.

Not everything is carried on containers. A comment a few days ago suggests a grab was being used to empty the detailed wagons - suggesting this was not a container train.

[Chris M]

On another forum it was stated that the train that derailed on the Goblin was conveying spoil, so it was most likely hopper wagons.

[greggygreggygreg]

We could put a member of staff on the back of the train. We could call them a guard.

[d7666]

The comment I referred to and quoted did explicitly state containers.

Hence my comment about ........ Containers.

[Deleted]

Feb 2, 2020 20:50:23 GMT greggygreggygreg said:

We could put a member of staff on the back of the train. We could call them a guard.

What and wait for the screaming

[rincew1nd]

Feb 1, 2020 14:28:50 GMT class411 said:

As we've been asked to keep the Gobby line derailment thread on topic, I'm making this point here.

Someone suggested having each wagon with it's own weight measuring system, which was rejected by many on the grounds of cost - which seems reasonable.

Earlier in that thread I suggested that the rear of each goods train be fitted with a (or a pair) forward facing camera(s), transmitting images of the train to the cab.

This would not prevent derailment, but it would - provided that the driver paid attention - prevent a train with a derailed wagon or wagons from doing the amount of damage that has happened in this latest incident.

I'm pretty sure that the cost of such provision, even on a hundred trains - would be substantially less than the many millions it will cost to deal with this single incident.

I've moved several posts from this thread to here, as the two threads were discussing the same thing concurrently the discussion may not seem to flow as it would usually. Unfortunately there is nothing I can do about this.

[Chris M]

The RAIB's initial summary states that only one wheelset, on the 16th of 22 wagons, derailed. Unless it was kicking up dust, etc. (and there is no guarantee that it was), that would have been very difficult for any visual system to detect - including by a guard looking from the back of the train.