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Comment by kposehn | Hacker News Reader

Very cool. If you could also make a smaller one with ~3kw output that fits on a locomotive frame you'd literally have the entire freight rail industry the world over as customers.

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Would you though? A lot of freight lines in europe are already electric, wouldn't it be much more efficient to have a stationary high-power reactor than carrying around a smaller one on each locomotive?

That might be balanced somewhat by not needing to maintain thousands of miles of caternary wire.

I think maintaining thousands of miles of wire and one large powerplant would be cheaper than maintaining thousands of small mobile reactors, but that's just speculation of course. And most of the wire has to already be there anyways for passenger transport, I think, because many rail lines are used by cargo and people. Unless every train should have a reactor?

Once we have cheap miniaturized fusion reactors, that work stable - we won't need so much electric wiring anymore, true.

Unfortunately, so far exactly 0 working fusion reactors have been build, so currently, I would not demolish electric lines just yet.

The underlying technology does not exist in a production form, to the extent that it's not clear which basic reactor design option is going to be the future. So we can't know what the maintenance burden from a fisson rector is, much less one mounted on a train. Don't plan on tearing down those overhead cables just yet.

In europe sure, in the US most of freight rail isn't and companies operating those rail roads don't want to spend money on eletrifying railroads.

Currently they're trying to gas light us that hydrogen-hybrid locomotives are the futures (why not use diesel-hybrid locomotives that already exist is a mistery)

trains in the US have electric motors that actually make the wheels turn.

The issue with the US is the distances trains have to go. Mostly short distance trains will be(are?) fully electric but long distance and frieght is diesel series hybrid engines.

Sorry, I wasn't clear in my comment. I was talking about trains that can use grid or diesel engine to power those electric motors.

And hydrogen comment was about this: https://www.energy.gov/eere/fuelcells/articles/usdot-announc... . My tinfoil hat theory is that every carbon-fuel company pushing for hydrogen knowing well it's energy density isn't enough, so the experiment will fail, and they're going back to diesel saying that green tech isn't ready.

I'm still confused, but that's ok. I spoke to why we don't use electric trains in the US, because the distances are too far and the terrain is too varied. The rockies, the cascades, just to get imports from west to east. No matter what, the power plant will have to be on the freight trains in the US. In the US, all freight trains are electric series hybrids, with diesel power plants.

I doubt hydrogen will ever go, because people like me will say "Hindenburg, but already on the ground where it can do the most damage, plus moving at 50-80MPH"

I get that, but US freight doesn't want to eletrify railnetwork at all. From my understading this is because even where it's totatly doable, but financially not feasable for various reasons (IIRC one of them are double stacked containers?).

4.5MW of power for GE 6000 locomotive (might be incorrect but it comports with other comments here), and i routinely see freight trains with 3 or more locomotives (i've seen way more than 3, but i don't have a picture or anything). In the midwest, where it's flat, trains can be miles long. I've counted over 250 on a single train before. and that's 4+ locomotives, so >18,000,000 watts.

I guess they could keep freight trains real short so they're single engine, but that's still 4 and a half million watts stall. Each one can move itself plus at least 10,000 tonnes (i don't know the conversions, nor care, it's a lot of mass) The world record is 82,000 tonnes, 4.5 miles long, 682 cars, 8 locomotives - in Australia, with american locomotives, hauling iron ore.

I have to ask, are you from or in the US?

GE does make a battery powered locomotive, designed to be used for regenerative braking, it can run at full power by itself for a half hour or so https://en.wikipedia.org/wiki/Wabtec_FLXDrive 3,200,000 watts.

3kW output? I think you mean 5MW output... large electric locomotives are in 2.5 to 3.5MW continuos power. Some diesel-electric huge ones are even larger, like 5MW.

Yeah must’ve meant MW.. I’ve got more than one 3KW generator at my house and they can barely run my AC much less a locomotive.

Yes, I meant MW

Why is that sounding like hydrogen trains all over again.

Radiation shielding scales poorly in the downwards direction.

I meant MW :P

I think my induction hob is roughly 3kW. Why don't we all just put a nuclear reactor in our basement at that point? You people are all dreaming.

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