Post diesel…how do you rescue a train?

[Meerkat]

Obviously the real answer is probably that diesels will get derogations for many years, but if not how would you rescue a failed train, a train with flat/failed batteries, or wires down stranded train?
I'm assuming batteries and hydrogen would have the same issues as for freight - not enough power/range in a small enough volume/weight limit, or will there have to be some monster three or four bogied battery or hydrogen locos?
I assume a similar requirement faces engineering trains.
On a similar point how big is a fast charger, a cable reel, and a battery pack big enough to put a full charge in a train? I’m thinking partly for a train that has run out of juice, but mainly if a train got to Uckfield (for example) and found the charger was knackered. Could you have the above on a lorry to send out?

 

[zwk500]

For emergency situations, you would only need to drag it as far as necessary to clear the line. So a limited capability is not necessarily a problem. And diesel won't disappear until the replacement traction options have enough range and power to cover the jobs anyway.

Depends on the charging system, but in theory you could have a transit van with an emergency booster in it. Obviously this would only work at terminals and for platforms adjacent to car parks. However I suspect that charging stations will have proving back to the Electric controllers so that they don't send something down a line if it won't get back out. It might also be possible to design the batteries to be able to be swapped wholesale, so a truck would turn up, put fresh batteries in and carry the flat ones back to the depot to charge.

 

[Bletchleyite]

Battery shunters for low-speed rescue? They are already a thing.

 

[Meerkat]

For emergency situations, you would only need to drag it as far as necessary to clear the line. So a limited capability is not necessarily a problem

I did ponder that but wasn’t sure. Once you have cleared the line you still need to get the failed train back to its depot, or the nearest electric wire/rail

 

[RobShipway]

For emergency situations, you would only need to drag it as far as necessary to clear the line. So a limited capability is not necessarily a problem. And diesel won't disappear until the replacement traction options have enough range and power to cover the jobs anyway.

Depends on the charging system, but in theory you could have a transit van with an emergency booster in it. Obviously this would only work at terminals and for platforms adjacent to car parks. However I suspect that charging stations will have proving back to the Electric controllers so that they don't send something down a line if it won't get back out. It might also be possible to design the batteries to be able to be swapped wholesale, so a truck would turn up, put fresh batteries in and carry the flat ones back to the depot to charge.

Not sure if it will be the case, but are the batteries used in trains suppose to have a 10 - 20 year lifecycle as it is in cars before not being able to be recharged?

But in the same aspect that you cannot driveaway a car while it is being charged, I would imagine it would be the same for the batteries on trains, otherwise you could be damaging them.

 

[Meerkat]

Battery shunters for low-speed rescue? They are already a thing.

Ones that can get to the site of the problem at mainline speeds?
How slow is a current diesel rescue?

 

[Bletchleyite]

But in the same aspect that you cannot driveaway a car while it is being charged, I would imagine it would be the same for the batteries on trains, otherwise you could be damaging them.

If you had power connected to the train, you'd not be driving it from the batteries, you'd be driving it from the power!

== Doublepost prevention - post automatically merged: 17 Jun 2021 ==

Ones that can get to the site of the problem at mainline speeds?
How slow is a current diesel rescue?

You could potentially locate them around the network at accessible places.

No need to run at linespeed if making only a short journey to the blockage.

 

[Meerkat]

You could potentially locate them around the network at accessible places.

No need to run at linespeed if making only a short journey to the blockage.

Maybe road railers, but otherwise that’s a lot of extra sidings, S&C etc.
as an example if a battery train failed at Uckfield wouldn’t you need to get it all the way to Oxted faster than a shunter could manage?
TBH I don’t know the scale issue - is battery/hydrogen impracticable for a cl66 replacement but practicable for something to do this example (a cl37 maybe??)

 

[SargeNpton]

Well, there's the old school way...

 

[Irascible]

You don't have to put diesel in IC engines, of course. AIUI sourcing biodiesel as a full replacement for refined diesel isn't practical, but in limited quantities - ie, rescue vehicles - it sounds a better idea.

 

[D365]

Not sure if it will be the case, but are the batteries used in trains suppose to have a 10 - 20 year lifecycle as it is in cars before not being able to be recharged?

Modern trains have moved away from the use of lead-acid. And it's worth pointing out that auxiliary and engine start batteries cannot be used for traction.

 

[zwk500]

Maybe road railers, but otherwise that’s a lot of extra sidings, S&C etc.
as an example if a battery train failed at Uckfield wouldn’t you need to get it all the way to Oxted faster than a shunter could manage?
TBH I don’t know the scale issue - is battery/hydrogen impracticable for a cl66 replacement but practicable for something to do this example (a cl37 maybe??)

If a train fails, you just accept that it's going to take time to clear the line. No different to if it had a brake failure or similar. At Uckfield anything that fails will be rescued by the following unit, not by a thunderbird.

You could potentially locate them around the network at accessible places.

That's a lot of shunters standing idle.

Not sure if it will be the case, but are the batteries used in trains suppose to have a 10 - 20 year lifecycle as it is in cars before not being able to be recharged?

But in the same aspect that you cannot driveaway a car while it is being charged, I would imagine it would be the same for the batteries on trains, otherwise you could be damaging them.

I didn't say anything about driving a train while charging. I said you'd replace the flat batteries with already charged ones, and the transit van would take the flat ones back to the depot by road to charge them. As far as the train is concerned, it now has fully charged batteries, so after a computer boot up it's good to go.

 

[LOL The Irony]

I think you'll just have our current arrangement but with whatever fuel source powering the locomotives rather than a fossil fuel powered engine.

 

[Meerkat]

If a train fails, you just accept that it's going to take time to clear the line. No different to if it had a brake failure or similar. At Uckfield anything that fails will be rescued by the following unit, not by a thunderbird.

Will a battery train have enough power/range to rescue another unit??

I think you'll just have our current arrangement but with whatever fuel source powering the locomotives rather than a fossil fuel powered engine.

That’s the point, was fuel source will be available and capable enough?

 

[zwk500]

Will a battery train have enough power/range to rescue another unit??

It may have to cut out the 'hotel' options to preserve battery life, but they won't operate on a line they couldn't perform the expected duties on. Diesels won't disappear until batteries are a mature tech.

 

[Meerkat]

It may have to cut out the 'hotel' options to preserve battery life, but they won't operate on a line they couldn't perform the expected duties on. Diesels won't disappear until batteries are a mature tech.

But you are suggesting a notably range limited power source is expected to have redundancy to drag another whole train!

 

[HSTEd]

You burn some diesel.

It's not as if train rescue moves are really a significant fraction of rail operations

 

[Meerkat]

You burn some diesel.

It's not as if train rescue moves are really a significant fraction of rail operations

I tend to think that is true, but if someone important enough says ‘NO diesels’ or councils start banning them there might not be so much flexibility. “You’ve known for ages” as per PRM.

 

[HSTEd]

councils start banning them there might not be so much flexibility

Do councils even have that power?
The railway is not a road after all.

 

[zwk500]

But you are suggesting a notably range limited power source is expected to have redundancy to drag another whole train.

No, I am suggesting that by the time batteries are considered mature enough to be the only power source available to an incident they will have developed sufficient capacity to perform rescue duties. Diesels won't be withdrawn wholesale until there's a clear succession plan. Remember rescuing only involves getting a train clear of the line to permit services to operate.

Do councils even have that power?
The railway is not a road after all.

No they don't, although they can of course lobby the DfT to specify non-polluting traction or engage with the operator on the subject.

 

[apk55]

There will always be some need for self powered or none electric locos. This will include working none wired sidings, engineering operations and rescue in event of a power failure.
However a most of this demand will probably be met by Bi mode locos, a powerful electric locomotive with a small diesel or battery or hybrid power pack that allows modest operation off wire. Class 88 is a typical example.
Even a highly electrified network like the Swiss network still has a number of diesels or bi mode locos available

 

[py_megapixel]

Remember rescuing only involves getting a train clear of the line to permit services to operate.

Indeed.

Looking at the three scenarios displayed in the original post:

• If the wires were down or the power was lost then what would be the advantage of clearing the llne, given that in this hypothetical electric-only world, you couldn't really get any more trains through?
• If the unit failed [but the wires were still operational], then it could be rescued by an electric loco
• Battery operation can only realistically happen on small branch lines until technology massively improves (and if it does, our speculation here becomes irrelevant). So if the batteries run out, you will only be blocking that small branch line, not a mainline. It could mean chaos on that branch, but assuming the diagrams were well-planned it will be possible to contain it to that branch only and not disrupt the rest of the network - so a delay in rescuing is probably not a major issue.
  Plus I imagine it will be planned out so that flat batteries in service almost never happen. When did you last see a DMU fail in service because the fuel ran out?

 

[Meerkat]

Diesels won't be withdrawn wholesale until there's a clear succession plan

Once a political deadline gets set….and then the succession plan goes wrong….

If the wires were down or the power was lost then what would be the advantage of clearing the llne, given that in this hypothetical electric-only world, you couldn't really get any more trains through?

You might need to clear the line to get to the wires that need fixing. You also don’t want to be unloading all the passengers out in the sticks, nor waiting until the wires are fixed before you can start getting the trains into the right places to restart services!

If the unit failed [but the wires were still operational], then it could be rescued by an electric loco

Not if it fails when it is on battery power.

It could mean chaos on that branch, but assuming the diagrams were well-planned it will be possible to contain it to that branch only and not disrupt the rest of the network - so a delay in rescuing is probably not a major issue.
Plus I imagine it will be planned out so that flat batteries in service almost never happen. When did you last see a DMU fail in service because the fuel ran out?

Whether or not the delay ‘doesn’t matter’ (not sure the local politicians will appreciate that attitude) you still have to rescue that train.
Diesels get fuelled days apart, the batteries are going to need recharging each trip and if it gets to the charger at the end of the line and the train and the charger don’t want to talk to each other…..

 

[paul1609]

It may have to cut out the 'hotel' options to preserve battery life, but they won't operate on a line they couldn't perform the expected duties on. Diesels won't disappear until batteries are a mature tech.

I think this is one of the issues with units in multiple as on the Uckfield lline. If one unit of a morning peak fails south of Hurst Green it will cause a cascade ffailure because the two good units wont have sufficient baytery capacity to return to the 3rd rail. If a 12 car unit fails on one of the single line sections it would take all day to recover the service.

 

[RobShipway]

Diesels get fuelled days apart, the batteries are going to need recharging each trip and if it gets to the charger at the end of the line and the train and the charger don’t want to talk to each other…..

Then the driver would be reporting an issue with the power of the train, in much the same way as happens now.

Once battery power is mature enough, it should just be a case that the batteries are charged overnight for the next day. In time you will either have the lines electrified where the battery packs are used on the trains or you will be at a point where batteries when they are charged last for two or three days.

When it comes to rescuing a train with passengers on, then it would be a case of unloading the passengers at the nearest station and then moving the broken train into sidings, which is no different than happens today with current power sources for trains.

 

[skyhigh]

When did you last see a DMU fail in service because the fuel ran out?

That would never ever happen. Oh wait... (it happens more often than you'd expect)

 

[Meerkat]

Then the driver would be reporting an issue with the power of the train, in much the same way as happens now.

Once battery power is mature enough, it should just be a case that the batteries are charged overnight for the next day. In time you will either have the lines electrified where the battery packs are used on the trains or you will be at a point where batteries when they are charged last for two or three days.

When it comes to rescuing a train with passengers on, then it would be a case of unloading the passengers at the nearest station and then moving the broken train into sidings, which is no different than happens today with current power sources for trains.

I think you are being very optimistic about battery capacity improvements. AIUI they are getting near the limits of what can be done with current chemistry and any radical improvement would require a chemistry breakthrough.
you still haven’t explained how you get the train from the sidings (are there really that many of those left that you would want to leave an expensive unit in??) back to the depot to be fixed.

 

[RobShipway]

I think you are being very optimistic about battery capacity improvements. AIUI they are getting near the limits of what can be done with current chemistry and any radical improvement would require a chemistry breakthrough.
you still haven’t explained how you get the train from the sidings (are there really that many of those left that you would want to leave an expensive unit in??) back to the depot to be fixed.

If the train has broken let's say at just outside of Redhill, would you really want to be dragging it back to Selhurst with passengers on? The answer to the question is no, you would take the train into Redhill station to unload the passengers. Once the passengers have been unloaded, you would be placing the train in sidings until an available path was found to be taking it back to Selhurst.

With regards to being very optimistic about battery capacity improvements, yes I am as technology is always improving. They would probably be all rotten by now, but you had a new unused AA battery from 20 plus years ago, that would not last as long as an AA battery built today, as different techniques are used today to be making batteries than where used 20 years ago. Yes, they are near the limits as to how much power can be placed into batteries especially those that can be recharged. But like any technologies, improvements are always being made. Back in the late 1970's, as a child I said to a relative that in the future all makes of cars will be able to have electronic windows and was told that would never happen........ What has happened in the last 30 years with cars?

You also have to remember that there is many developments happening in electric cars, which in 5 - 10 or 20 years time will mean that they can go for longer distance than they do currently using the same amount of battery power. That technology will at some point come over on to the railways, to help make a better greener planet for us all. It is just that you have to be patient as it will take time for things to be developed.

 

[Meerkat]

but what if the unit is o/s in Uckfield platform? You need to get it onto the third rail, and you want to do it quickly as you can’t run trains to Uckfield until you do. So in a non-diesel world you need something that has the range/power to get itself to Uckfield from the 3rd rail, and then tow a whole train back again, at reasonable speed.
You cannae break the laws of physics (and chemistry)….
Technology can’t just keep increasing, things hit viability barriers. We don’t all have the flying cars my childhood books promised and supersonic air travel hit a viability barrier.

 

[option]

The question of 'How do you rescue a train?' depends on the failure mode.

So, what is the failure mode of an electric train?
If it's a systems/physical failure, then it will need rescuing by something. I don't see an issue with having rescue locos operating on diesel/biodiesel.*
The train will only need to be taken to the nearest major station & then taken out of service.

If it's an OLE issue, then use the back-up batteries to get out of the area with an issue.
(which the train has because it's either designed to run to a final destination that doesn't yet have wires, or it's just got back-up batteries)

It's unlikely to be a battery issue, see below.

As for "if it gets to the charger at the end of the line and the train and the charger don’t want to talk to each other….."
The powerful chargers are already being used for electric buses, & they are obviously reliable enough for that.
Also, would they need charging at every turnaround?
New electric buses have >300km range; https://pelicanyutong.co.uk/go-north-east-voltra-e10-electric-buses/
A round trip Oxenholme-Windermere is 32km, so 10 round trips seems doable.



Battery technology is improving all the time.
Tesla have redesigned their battery cell from scratch; new chemistry, new physical details, etc.

Everything You Need To Know About Tesla's New 4680 Battery Cell - CleanTechnica

Tesla didn't hold back at Battery Day, announcing a new tabless 4680 cell form factor, among many other things.

cleantechnica.com

The cells are then bundled into modules, & you have multiple modules to make the battery pack. So even if a module fails, there are still other modules to provide power.
Battery packs can be made in different sizes & shapes, so you can fit multiples of them to a vehicle. So even if a pack fails, there are still other packs to provide power.
(as an example, a Class 800/802 five-car set has three generator units, which also means three fuel tanks. So there's space for 6 battery packs, two per car.)

* biodiesel is being made from waste products like used cooking oil & sugar beet, so there will be availability.