Should FOCs be required to fit Electronically controlled pneumatic (ECP) brakes?

[Belperpete]

I thought we came into this from the premise that we needed ECP to prove train length? If checking the pressure in the brake pipe isn't good enough for train completeness then just jumper two wires down the train and connect them together only at the far end. This could be made so it only worked by plugging into a special socket on the tail lamp. As the original reason for ECP to manage stopping in very long trains doesn't really apply in Europe, don't we just have a solution in need of a problem?

I think you are confusing proof of train length and proof of train integrity. Checking brake pipe pressure can't be used to prove train integrity, as otherwise you would get an integrity alarm every time the driver applied the brake. An end-of-train device as you suggest could be used to prove train integrity, but it does nothing to prove that the correct train length has been entered.

 

[edwin_m]

I think you are confusing proof of train length and proof of train integrity. Checking brake pipe pressure can't be used to prove train integrity, as otherwise you would get an integrity alarm every time the driver applied the brake. An end-of-train device as you suggest could be used to prove train integrity, but it does nothing to prove that the correct train length has been entered.

Applying the service brake keeps a certain pressure in the pipe. A parted train reduces it to zero, so could in principle be detected.

 

[Belperpete]

Hopefully the people composing the train should know how long the train they are supposed to be driving today is.

There are frequent incidents where drivers get their train length/composition wrong.

 

[edwin_m]

This only protects against a fault when the wagon control system fails, and yet the wagon control system still responds to a fall in air pressure in the train line?
I am skeptical you get a meaningful increase in safety from such a measure, but ok.

Depends what you mean by the wagon control system. I am suggesting that each wagon still has a conventional air brake in addition to the ECP control unit, and that would apply the brakes in the event of loss of train line pressure.

Hopefully the people composing the train should know how long the train they are supposed to be driving today is.

If you're prepared to rely on that, why not just let them put that figure into the "system" and be done with it?

And as I suggested above, the first time the train drives over an axle counter leaving the yard, it should be possible to tell the train how many axles it has.
It should know how many axles it has, if those numbers don't match up you have an unknown vehicle or vehicles in the formation.

You could do that but have introduced an extra interface to the signaling system. And I thought the idea was to get rid of axle counters?

So you want to install jumper cables down the entire length of the entire freight fleet?
That will cost a substantial fraction of the cost of the ECP system!

"A substantial fraction of", but nowhere near "all of", especially when maintenance cost is taken into account as well.

 

[HSTEd]

Depends what you mean by the wagon control system. I am suggesting that each wagon still has a conventional air brake in addition to the ECP control unit, and that would apply the brakes in the event of loss of train line pressure.

There have been installations that have done this in the US, but at a significant extra cost per wagon so fitted.

IIRC it was about $2,000 per wagon, so given the costs in the railway in the UK, not really anything.
I suppose the ultimate question is how much you are willing to trust the computers in the wagons not to fail wrong side.

EDIT:
In summary, if it can be done for such a price - we should probably do it as you say.
Its probably cheaper than the computer reliability engineering.

If you're prepared to rely on that, why not just let them put that figure into the "system" and be done with it?

Well the error of entering a number wrong is different from the error of not noticing that the figures on the display are wrong - they have different probabilities in human factors models.
After all you would instruct them to read off every wagon in the train and tick it off against their manifest checklist.

If the error is detected at any step in the process then you have detected the fault and the "everything is fine" mindset in the operator dissapears and they become more likely to notice the overall problem.

You could do that but have introduced an extra interface to the signaling system. And I thought the idea was to get rid of axle counters?

I was proposing to get rid of axle counters on plain line, not on areas where shunting may occur or junctions are located. Those being areas where all the trackside infrastructure has to exist regardless, so the cost plugging in some axle counters is minimised.
Even keeping the latter still eliminates a huge fraction of the total infrastructure.

 

[MarkyT]

I believe that such systems are already being developed. However, you would still require equipment on the ground, which would need a power supply.

True, but the tech could become increasingly lean in consumption and perhaps might one day be possible to support reliably on local solar/wind source power with battery storage alone, or with a low quality 'domestic' supply, where that avoided an expensive redundant power feed. Also track to train comms is likely to be come more distributed with smaller more localised trackside cells in the 5G style, so the control and comms functions could become more integrated in the future and share power and trunk data connections. Also, perhaps a balise, in addition to returning a data telegram, could plausibly collect sufficient energy from a passing train's interrogation pulse to also power some lineside axle counting processing and intermittent radio communications.

 

[Nym]

ETCS wasn't conceived for the UK - the clue is in the name "European Train Control System".

I'm aware of who conceived ETCS, but I'm sure you'll be aware that someone, in this country, has planned it's roll out and local specific parameters...
Please cease assuming everyone you talk to is thick.

 

[Belperpete]

I'm aware of who conceived ETCS, but I'm sure you'll be aware that someone, in this country, has planned it's roll out and local specific parameters...
Please cease assuming everyone you talk to is thick.

Apologies, I am not assuming that you are stupid, but your posts do display a level of ignorance about ETCS matters. The rollout of ETCS level 2, that is in progress, inherently takes account of freight vehicles, as ETCS level 2 requires trackside train detection. It is the desire to move away from expensive trackside train detection to a level 3 type system that is being discussed here. No one has planned a rollout of ETCS level 3, as there isn't yet a working system to rollout on a mixed traffic railway. Basic problems of train length and integrity are still being addressed, as being discussed.

 

[Nym]

Level 2 actually doesn't consider the operations of freight vehicles fully. In addition to the points you addressed.
The same is also true for some types of LHCS passenger formations.