Would Battery Tenders Work for Electric Locos off the Wires?

[biggerisbetter]

Would it be feasible for a 'battery tender' to be used for intermodal freight trains to allow a greater number of services to be run with electric locos where there is a proportion of running on non-electrified track? I would envisage a standard shipping container pod loaded onto the first wagon behind the loco on an intermodal train and linked via cable. This would then allow easy replacement of the battery pod and re-charging at times favourable rates can be secured from the grid. Would presumably require some adjustments to the locos to allow this but would it be feasible as a method of reducing diesel under the wires and reducing carbon emissions? Thanks in advance and apologies if covered previously.

 

[Grumpy]

Would it be feasible for a 'battery tender' to be used for intermodal freight trains to allow a greater number of services to be run with electric locos where there is a proportion of running on non-electrified track? I would envisage a standard shipping container pod loaded onto the first wagon behind the loco on an intermodal train and linked via cable. This would then allow easy replacement of the battery pod and re-charging at times favourable rates can be secured from the grid. Would presumably require some adjustments to the locos to allow this but would it be feasible as a method of reducing diesel under the wires and reducing carbon emissions? Thanks in advance and apologies if covered previously.

I don't know the answer but wonder if the idea could be widened eg a battery tender similar to the old brake tenders (but filled with batteries rather than concrete) , attached to such as surplus 379/350/2's replacing DMU's

 

[SynthD]

Interesting idea. What capacity would the cable need?

 

[Ashley Hill]

And could power preserved electric locos on preserved railways. I need the 84 for haulage .

 

[Snow1964]

I can't see any logical reason why it wouldn't work

Whether the unions would like something like modern equivalent of old brake tender, or if it is economic I do not do

I guess an alternative is a paired double loco, effectively two single cab locos permanently coupled together with batteries in second one.

 

[contrex]

What capacity would you want the battery to have? I believe rechargeable Li-On battery 'blocks' are about $140 per kilowatt-hour. let's say you want to run a 2,000 HP (1.47. MW) loco for 1 hour, that's (perhaps!) 1.47 x 1000 x 140 dollars for the battery or 205,000 US dollars, or £161,000. For one battery, before you've put it inn a container and wired it up, or bought and installed charging gear.

See here

Battery-Electric Tender for Modern Railway Propulsion - Railway Age

A battery-electric locomotive tender can be built using a modified production freight car chassis and carry long-life, grid-scale battery technology. It may operate as a companion to either a diesel-electric or battery-electric locomotive, offering advantages that include more efficient use of...

www.railwayage.com

 

[JamesT]

What kind of connector would you need between the tender and the locomotive to carry power? Are you expecting the tender to be detached in normal service?
As I understand it, there aren't existing trains with an easily detachable cable carrying high power between carriages, that kind of link is essentially hard wired between members of a unit if at all.

Does the contract for electric traction power vary over time?

Given the issues we've seen with previous attempted conversions of old trains to cope with new power sources, perhaps it might be cheaper to buy new locomotives that already have batteries?

 

[edwin_m]

Interesting idea. What capacity would the cable need?

For revenue freight, approximately the power at rail of the locomotive divided by the voltage used in the connection, plus a bit for losses. A Class 66 is 1850kW at rail, so a 750V link would be carrying about 3000 amps when full power was needed. That's a fairly chunky cable.

And could power preserved electric locos on preserved railways. I need the 84 for haulage .

The 84 (along with the other classes 81-87) are controlled by a tap changer on the transformer, and transformers don't work on DC. So it would need some major internal modifications to work on a DC supply.

 

[contrex]

I can't help remembering BR's 1970s sodium-sulphur battery idea

 

[JamesT]

For revenue freight, approximately the power at rail of the locomotive divided by the voltage used in the connection, plus a bit for losses. A Class 66 is 1850kW at rail, so a 750V link would be carrying about 3000 amps when full power was needed. That's a fairly chunky cable.

The 84 (along with the other classes 81-87) are controlled by a tap changer on the transformer, and transformers don't work on DC. So it would need some major internal modifications to work on a DC supply.

Or put an inverter on your tender and supply AC across the link?

 

[contrex]

As I understand it, there aren't existing trains with an easily detachable cable carrying high power between carriages, that kind of link is essentially hard wired between members of a unit if at all.

The Southern Railway had power jumpers linking 2000+ HP emus in the 1930s.

 

[172007]

First container on a liner as a 20ft Battery. Mever heard anyone suggest the concept but it would work and can also be swapped out for a fully charges unit every terminal. Now i know the usual comments are the last few containers are the profit but a class 99 with a 20ft battery is less lengh overall than twin class 90. Just a thought.

 

[contrex]

There's a preserved rural railway in France where they run an old ex-metro Sprague emu up and down using a diesel generator set up in one of the coaches.

 

[edwin_m]

Or put an inverter on your tender and supply AC across the link?

You'd have to step it up to 25kV too, which sounds pretty scary in a pluggable connector.

 

[172007]

You'd have to step it up to 25kV too, which sounds pretty scary in a pluggable connector.

Cables don't look that big on Pendolinos etc, tripple the diameter of the cable and it ought to still be practical. Down to how much the Foc's and Network rail plus the RSSB want the railway to become as Carbon neutral as possible.

 

[36270k]

A simpler solution would be a battery shunting loco to move trains between the reception road and terminal

 

[bib]

Presumably if they can do it with a hydrogen tender they could also do it with a battery tender

From 2025, Nestlé Waters France will use the first hydrogen-powered freight train through an innovative solution developed by Alstom and ENGIE

Nestlé Waters will be the first company in Europe to benefit from the hydrogen fuel cell solution developed by Alstom and ENGIE, for rail freight.

www.alstom.com

 

[eldomtom2]

This is an idea that's been brought up a lot recently but has yet to see any trials. It smells a little bit of gadgetbahn to me.

 

[HSTEd]

I'm not convinced this would ever work out to be superior just to fitting the largest available battery into a Co-Co locomotive. With modern traction converters the bulk of the mass of the unit can be batteries.

 

[edwin_m]

Cables don't look that big on Pendolinos etc, tripple the diameter of the cable and it ought to still be practical.

The roof top cable on a Pendolino is 25kV so carries about thirty times less current than it would at 750V. The size of a cable depends mostly on the current it is to carry.

Third rail EMUs have a bus cable along the length of the unit. That will be carrying 750V, but at a lower power (and hence lower current) than would be needed to run a 66.

 

[43096]

Would it be feasible for a 'battery tender' to be used for intermodal freight trains to allow a greater number of services to be run with electric locos where there is a proportion of running on non-electrified track? I would envisage a standard shipping container pod loaded onto the first wagon behind the loco on an intermodal train and linked via cable. This would then allow easy replacement of the battery pod and re-charging at times favourable rates can be secured from the grid. Would presumably require some adjustments to the locos to allow this but would it be feasible as a method of reducing diesel under the wires and reducing carbon emissions? Thanks in advance and apologies if covered previously.

Every extra non-revenue earning part of the train tips the financial case against it. That last wagon or last container is your profit, and in many cases you can’t run a longer train as they are maximum length already.

 

[Bald Rick]

Yes, entirely feasible. Although probably not so sensible as a lift off/on container. More sensible as a semi- permanently coupled ‘drogue’ loco with no pan or motors. And yes, every length of train matters, but then we ran Freightliner with doubled headed 86s for over half a century, and this would be no different.

I posted something similar months ago. But from memory, a battery ‘tender’ loco would have capacity for around 6-8MWh with LiTo batteries (much longer life than Lithium Ion), and that would be good for 4-6hours driving time off the juice (ie excluding time stationary). Coupled next to something like a Class 99 that has a (much) smaller battery capacity instead of the diesel (say 1MWh), there wouldn’t be many freight duties beyond it, providing suitable opportunities for charging are available at terminals etc.

 

[popeter45]

as others have said yes the idea of a tender makes sence but issue is connector as unlike a permanent cable, connectors need to be larger and carry safety systems escpecially if in reachable area of crew or the public
one abiet stupid but could work idea would be extending a overhead rod to interface with the pantograph?, would keep all 25KV connections above the orange high voltage danger line?

 

[Bald Rick]

as others have said yes the idea of a tender makes sence but issue is connector as unlike a permanent cable, connectors need to be larger and carry safety systems escpecially if in reachable area of crew or the public
one abiet stupid but could work idea would be extending a overhead rod to interface with the pantograph?, would keep all 25KV connections above the orange high voltage danger line?

That’s one solution. However there’s no reason why the cable couldn’t be permanent; it effectively becomes one big loco in two separate packages. I’m sure there’s proper terminology that I can’t remember!

 

[popeter45]

That’s one solution. However there’s no reason why the cable couldn’t be permanent; it effectively becomes one big loco in two separate packages. I’m sure there’s proper terminology that I can’t remember!

either articulated if Bo'Bo'Bo or twin unit if Bo'Bo+Bo'Bo / 2(Bo'Bo')

 

[eldomtom2]

That’s one solution. However there’s no reason why the cable couldn’t be permanent; it effectively becomes one big loco in two separate packages. I’m sure there’s proper terminology that I can’t remember!

At which point you have ended up with a much bulkier loco for the same amount of power compared to OHLE or diesel alternatives. I doubt companies will be rushing to buy them.

 

[JohnElliott]

as others have said yes the idea of a tender makes sence but issue is connector as unlike a permanent cable, connectors need to be larger and carry safety systems escpecially if in reachable area of crew or the public
one abiet stupid but could work idea would be extending a overhead rod to interface with the pantograph?, would keep all 25KV connections above the orange high voltage danger line?

Pre-war SR multiple units had a 660v bus line between units (the socket was also used for depot power, and was carried by post-war units for the same purpose) so I don't think physics would rule out an autocoupler with a connector of similar size. That would only be appropriate for a loco with a suitable DC power stage, of course.

 

[JamesT]

Pre-war SR multiple units had a 660v bus line between units (the socket was also used for depot power, and was carried by post-war units for the same purpose) so I don't think physics would rule out an autocoupler with a connector of similar size. That would only be appropriate for a loco with a suitable DC power stage, of course.

The power output of a 4SUB according to Wikipedia is 750-820kW, presumably the power jumper would have been specified to cope with that kind of load. Whereas a class 90-92 is in the region of 4-5MW. That’s considerably larger, so I don’t think you can assume that because the older system worked it necessarily scales up.

There’s also mention (though no source) of the jumper cables being banned from BR era units. Presumably that was on the basis of safety to have such a powerful connection exposed where staff might interact with it. If that was an issue then, I doubt our more risk averse world would contemplate allowing it.

 

[AM9]

Cables don't look that big on Pendolinos etc, tripple the diameter of the cable and it ought to still be practical. Down to how much the Foc's and Network rail plus the RSSB want the railway to become as Carbon neutral as possible.

The cables carry less than on a class 390 carry less than 240A at 25kV. At a safer voltage, permissable below the yellow band, (say 1KV), would need to carry 6000A, so it would be a lot thicker than three times the Pendolino 25kV bus line!

 

[GRALISTAIR]

Which of course we already have - the Clayton Class 18s