Battery Powered Locomotives?

I'm wondering if this is possible? My knowledge level about day to day rail operations is limited to average railfan level. I'm also not an engineer (train or otherwise), nor am I trying to be the guy has the magic idea that change the world's transportation industry. I'm just curious about the practicality of this.

The idea I had was basically a box car that was a giant lithium ion battery. The most important question is, is there enough power from a battery like this to run a train for a useful amount of time. Trains have the great advantage that its insignificant to make the train a few feet longer. So, say you had a box car that was all battery, you could pair that up with a custom tanker car if needed that had the sole purpose of cooling that battery. Also in theory you could plug existing locos right in and run them as slugs with the diesel engine off, right? If so, that diesel would also make for a nice safety net to prevent stranded trains, or switching then the battery is dead to at least electrify part of the route.

I wouldn't see a setup like this being something that a railroad would convert their whole fleet to. More like slowly ease it in on specific routes where it would be well suited. You probably wouldn't be able to charge these on site, you'd probably have to have your own network of "batteries" that you move around your network, to and from those key routes, to charging spots. The benefits of working in bulk would probably make it worthwhile moving whole trains of dead batteries and swapping them with trains of charged ones. You could build charging stations in areas where you can get cheaper power, like building your own hydro electric dam or wind farm specifically for the purpose of charging.

Without doing any math, it seems like a plausible system to set up on a small scale that could help things be much more environmentally friendly, and with enough scale, probably cheaper where used. (assume gas gets back to $4+).

But of course, comparing this system to diesel probably is the wrong comparison. The real question is probably, would it be cheaper than electrifying the route, or specific, key routes, the traditional way? I suspect it would be given how freight routes tend to me much longer while seeing a far lower rate of trains than say a popular commuter rail route.

All that said, if not lithium ion, at some point there will likely be a battery technology dense enough to be able to move a train.

Also this made me wonder, can you basically just stick catenary on the top of a diesel, connect the power to the track motors, turn off the wheels and have it go? Or, have a motor-less car behind the locomotives which had the sole job of grabbing power from the overhead lines, and feeding it into traditional diesel locomotives with their diesel engines turned off? If something like this could work, why did I have to wait in my Amtrak train in Hartford CT for 45 minutes so many times as a kid, while they changed locomotives on the train? This is mostly off topic but not entirely.

Lastly, I searched the internet on this topic before I started writing this, but I didn't find anything. That's because battery powered model/toy train locomotives exist, absolutely killing my google search :D

Modern locomotives use a LOT of power, and I suspect that even a freight-car-load of batteries wouldn't pull a large freight train very far (with luck someone else who knows more can do some back-of-the-envelope calculations and let us know about this!), but the basic idea is not a silly one.

Battery-powered switch engines have been around for a LONG time, though (perhaps because of limitations of early 20th C battery technology?) I think they have tended to be more for industrial (in plant) than Class 1 yard switching. One very attractive instance from the late 1930s was a GE switcher -- used, I think, at a GE plant -- whose carbody design was similar to their slightly later 44-ton diesel.
Various experiments have been announced in the past decade or so: I'll let someone who remembers them better than I do give you a report.

For slightly greater range or duration of operation, there is the "hybrid" option: a battery powered switcher with a comparatively low-power engine-generator set for recharging: in switching service you only need full power intermittently, so you could have a unit which can briefly "act" like a (say) 1600 hp switcher, using battery power, but makes do with a, say, 300 hp diesel engine for recharging. This idea also goes back a ways: I think 1600 hp for a bit, but with a 300 hp engine, was the rating for a whole class of units built by GE in the early 1930s, using the same Ingersoll-Rand engine used on the first "commercially successful" diesel switchers built in the 1920s by GE and Alco. … Most of these were built for use in the New York Central's electrified district around New York City and were "tri-power": battery, diesel engine, third-rail electric pick up. Two similar units were built for the DL&W for use under its New Jersey 1500 volt overhead electrification, and two or three without the equipment for third-rail or overhead pick-up for use in Chicago.

There has been some interest in diesel-battery hybrids in the past decade or so. A number of switchers were built under the "Green Goat" trade name: my impression is that they have not been successful because battery technology wasn't up to it: they tended to catch fire…
---
As for equipping a diesel locomotive so it can pick up power from an external source and work as an electric… Again, this is feasible and has been done. The Southern Region (think: electrified commuter lines outside London) of British Rail had a number of "electro-diesels" capable of operating off third rail, but also of taking the train beyond the end on the electrified district. And the New Haven Railroad's "FL-9" was similar: basically an EMD F-unit with a slightly elongated body (58 feet instead of 50) to accommodate passenger equipment and the extra electricals, which operated as a diesel "out-doors" but could turn off the engine and draw power from the third rail to go into New York's Grand Central Terminal.
I have seen a drawing of a proposed diesel-electric-electric from the late 1970s or early 1980s, when Conrail was thinking of electrifying over the Alleghenies and a number of Western railroads were investigating the possibilities of electrification. Basically an SD-40 (maybe on a slightly extended frame?) with the cab and engine, etc, moved forward eliminating the "front porch": the idea was that there would be enough room at the rear to install a transformer and rectifiers so it could draw power from an AC catenary. In operation, it would have been a 3000 hp diesel when not under wires, but (assuming electrification was limited to areas with steep grades where helpers would ordinarily be needed) under wire it could act like a 6000 hp electric.
And I think "diesel-electric-electrics" have been recently built, or are being built, for New Jersey Transit's commuter operations.
---
So: all good ideas! I'm not sure battery technology is yet up to purely battery-powered long distance freight trains, but for more local service these ideas have been recognized and used.

Lithium Ion batteries are amazingly power-dense. I imagine that one the size of a box car would probably move a train quite a distance. But at the same time, yeah that train might have a tendency to burst into flames. All of this is based solely on anecdotal evidence. The amazing acceleration and range of my friends tesla (yeah its only one car, not a train, but it's also only one small battery, not a box car's worth). I have power tools that use lithium ion, and when you take the battery holder apart, the actual lithium cell is TINY, maybe the size of two C batteries. It's amazing how much power you get out of those. But also cheap Li batteries are known to catch fire. And even non cheap ones can burst into flames if punctured.

Also the idea of electrifying the hills and turning a 3000 hp loco into a 6000 hp is very interesting. That's definitely not something I would think of.

One thing I did not think of is that overhead wires are AC and based on what you said, I am assuming locomotive motors are DC? This wouldn't be a problem for battery locomotives, but it would add a bit more needed machinery beyond just plugging the overhead power directly into the wheels. Still, modified locomotives or even extra cars containing overhead catenary and any/all electronics needed seems like a relatively cheap solution to knock locomotive switches off the schedule. Especially on very heavily travelled routes like the north east corridor. Of course this is all super moot now since it's electrified the whole way, but before it was. Although it would have been relevant again if the N-S Rail Link was a surface level link going through the greenway. Then NYC to ME trains would have to switch or be all diesel.

There are trams which operate from batteries or supercapcitors. They recharge from overhead wires at stations along the way. Also, mine railroads are commonly battery powered.

Maybe battery powered Yard Slugs, with regenerative braking? Do those exist?

l008com wrote:One thing I did not think of is that overhead wires are AC and based on what you said, I am assuming locomotive motors are DC? This wouldn't be a problem for battery locomotives, but it would add a bit more needed machinery beyond just plugging the overhead power directly into the wheels.

Most new locomotives use AC traction motors. Both GE and EMD have been producing AC freight locos since at leas the 90s (e.g. SD90MAC & AC6000CW). Amtrak's Gennies were DC (except the dual-modes), but the new Chargers are AC, as are the T's HSP-46's.

ISTR that there was some UK area rail service that used battery operated EMUs for years.

What's at the pan and what's at the motor are irrelevant these days - it all goes through a converter/inverter setup. What matters is DC link voltage, and getting that.

Honestly, I think supercaps/batteries might have more hope for "rescuing" gapped third rail equipment. Or as storage devices for regen on third rail systems that can't accept it (which are most, since most substations are just rectifiers, not 4 quadrant converters, though I'm sure someone overseas already uses those...). Be a lot better to stick that regen power somewhere useful than just burn it up in the resistance grids...

NS built a battery powered switcher in 2009 that is currently stored per Chris Toth's website: http://www.nsdash9.com/rosters/999.html" onclick="window.open(this.href);return false;

It was intended to be used for one or two shifts daily and recharge overnight. When the locomotive was first conceived, it was to use 60 GNB SLS-710 64 volt valve-regulated lead-acid batteries in three parallel strings, producing up to 1.500 armature amps per DC traction motor thru chopper modules with separately controlled fields. I was contracted to do the locomotive arrangement design and the detailed design of the battery racks, which I completed before it was decided to change direction and use 1,080 12 volt batteries. The first batteries tried did not work out as intended and a second try was made with lead-carbon batteries as Chris states. Apparently that didn't work too well either.

Dave