Could electrically-heated steam locos be a solution for preserved railways?

[HSTEd]

There are other options such as bio-coal, but even out of those options batteries are by far the least practical, and the furthest removed from what heritage railways are actually trying to preserve.

Well batteries are not the only electrically heated option, given that most steam locomotives in preservation only operate at a small fraction of their maximum output. They haul short and light trains a handful of miles at a time for the most part, even if they only use immersion heaters at the ends of the line they would still cut fuel consumption dramatically.

Bio-coal is also not a great option because once again its a hyper-specialised fuel used by noone else.

 

[AlastairFraser]

Bio-coal is also not a great option because once again its a hyper-specialised fuel used by noone else.

That's not necessarily going to be true forever. Biomass is becoming a very popular option for power generation, and increasing the energy efficiency of fuel there will help the business case for more biomass units.

 

[gravitystorm]

Let's say an electrically fired steam loco has twice the efficiency of a coal fired one.

I think there's a issue here with how different people might think of using electricity to heat the water. I'm sure if you put a 30-bar electric fire on the grate, and the electricity heats the air and the hot air flows through the pipes, that would work poorly. But if you either took some water from the boiler and heated it up in the tender (or made long thin electrical heating elements and put them down a few boiler tubes) then the efficiency would go up, since a much higher percentage of the energy ends up in the water. Your point about all the other inefficiencies in the system still stand, of course.

One characteristic of non-mainline locos that I would like to hear more about is how much of their fuel is used to bring the boiler from overnight cold to working temp while in the shed, vs how much fuel is used in motion. For a big engine on a short daily pootle, it seems like there might be more of a useful opportunity for stationary electrical pre-heating, but I don't have any knowledge to whether that's 50% or 2% of the daily fuel usage.

 

[trebor79]

One characteristic of non-mainline locos that I would like to hear more about is how much of their fuel is used to bring the boiler from overnight cold to working temp while in the shed, vs how much fuel is used in motion. For a big engine on a short daily pootle, it seems like there might be more of a useful opportunity for stationary electrical pre-heating, but I don't have any knowledge to whether that's 50% or 2% of the daily fuel usage.

25 years ago now, but from what I recall in my days of playing around with 060 tanks not much fuel was needed to get up from cold to working pressure.
A thin covering of coal on the grate, smashed up pallets on top, throw some burning oily rags on top. Shut the fire doors and go oil up/clean/have a mug of tea. About a couple of hours later throw another layer of coal on whilst trying not to get smoked to death.
Soon after than you might have 20-30psi, enough to operate the blower so you can fire it "properly" without smoke and flames coming back out of the fire hole. Clean the soot off the inside of the cab, wash face. Now we're at about 80-100psi, another round of coal and that would get you up[ to working pressure.
First run (it was a very steeply graded line) was always the hardest and not unusual to be struggling a bit by the top with a thin fire not holding steam as well as later in the day, but I soon learnt to bank the rear up a bit once the blower was available.

On the line we worked I'd say about 10%-15% of the coal was used bringing from cold to full steam, but depends on lots of things of course. When it went from 6 to 4 round trips per day to save fuel that proportion increased.

 

[Dent]

I think there's a issue here with how different people might think of using electricity to heat the water. I'm sure if you put a 30-bar electric fire on the grate, and the electricity heats the air and the hot air flows through the pipes, that would work poorly. But if you either took some water from the boiler and heated it up in the tender (or made long thin electrical heating elements and put them down a few boiler tubes) then the efficiency would go up, since a much higher percentage of the energy ends up in the water. Your point about all the other inefficiencies in the system still stand, of course.

That was presumably where the assumption of twice the efficiency came from, and the subsequent calculations showed that even if twice the efficiency is assumed, the amount of batteries required is still unpractically large.

 

[Peter Wilde]

That's not necessarily going to be true forever. Biomass is becoming a very popular option for power generation, and increasing the energy efficiency of fuel there will help the business case for more biomass units.

Interesting idea but not sure if this works. Thought the point of developing biocoal - a work in progress - was specifically to make a coal-like fuel suitable for heritage steam engines. Jury is out on whether or not it will prove economically feasible and can be made "green” enough (e.g. can be made nearly 100% from wood, not with a large percent of coal dust in the mixture).

Biocoal is not going to be good for large scale power generation unless the amount of energy used in the fuel-manufacturing process does not negate the advantage gained when burning the concentrated fuel in the power station. I suspect the economics of that may never add up, but does anybody know?

 

[AlastairFraser]

Interesting idea but not sure if this works. Thought the point of developing biocoal - a work in progress - was specifically to make a coal-like fuel suitable for heritage steam engines. Jury is out on whether or not it will prove economically feasible and can be made "green” enough (e.g. can be made nearly 100% from wood, not with a large percent of coal dust in the mixture).

Biocoal is not going to be good for large scale power generation unless the amount of energy used in the fuel-manufacturing process does not negate the advantage gained when burning the concentrated fuel in the power station. I suspect the economics of that may never add up, but does anybody know?

It can help deal with an inadequately future-proof electricity grid like so many developed countries have, producing a relatively low-carbon energy source when there is a surplus of green wind/wave/solar power in one area.
Orkney already produces green hydrogen as a surplus product of wind power.

 

[Zamracene749]

Can’t you attach the mains to the rails to get the electricity to the loco - no batteries required

Add a massive Relco and you wouldn't ever need to clean off any leaves either
Joking aside, the OP mentioned the future cost of the coal. I'm guessing here, but I'd imagine the cost of all these conversions ADDED to the actual costs of the electricity needed to eventually run these trains would far overwhelm the cost of just shipping in coal from elsewhere, or using poorer quality but still available opencast from the UK?

 

[Pigeon]

I'm sure if you put a 30-bar electric fire on the grate, and the electricity heats the air and the hot air flows through the pipes, that would work poorly. But if you either took some water from the boiler and heated it up in the tender (or made long thin electrical heating elements and put them down a few boiler tubes) then the efficiency would go up, since a much higher percentage of the energy ends up in the water.

It is true that extracting a decent percentage of the heat from the flue gases during their notably short passage through the tubes is a major source of inefficiency for a conventional steam locomotive. But I don't think anyone's suggesting just putting a heater where the fire used to be. The Swiss experiment used a great big immersion heater in the boiler, and that is surely the obvious way to do it.

And as has been pointed out, it's still nowhere near good enough.

The most effective "steam battery" technology that has been tried is to use the latent heat of solution/dilution of sodium hydroxide. The boiler has separate sections for water/steam and NaOH. After the steam has passed through the cylinders, instead of being exhausted it is led into the NaOH tank, where it interacts with the NaOH to release more heat to raise more steam. To reset the system you squirt hot dry steam through it, from an external source heated by anything you want, same as an ordinary "fireless" locomotive but with greater range.

This has a range of several miles, so it might be usable by the shorter steam railways by converting some of the locos from classes of which a disproportionately large number have been preserved. Might. But with no steam chuffing out, it kind of ruins the whole thing, so probably not.

That's not necessarily going to be true forever. Biomass is becoming a very popular option for power generation, and increasing the energy efficiency of fuel there will help the business case for more biomass units.

Don't be misled by the propaganda emitted by those crusty stains at Drax and their ilk. Biomass is a stupid option for power generation. Obtaining it from trees grown in remote areas half way round the world means the tree end operates pretty much entirely without supervision or enforcement, so the "sustainability" can be faked with outright lies and with vapourware promises for what they'll do in 20 years' time which they can then deliberately go bust to get out of, before restarting under a different name. They don't even have to try very hard, because everyone knows that plants grow themselves therefore they "must" be sustainable, and next to nobody thinks any further about it. And that's without considering the lugging of it half way round the world in ships burning fossil fuel. It's not "green", it's just (rather too effectively) greenwashed.

(The short-term liquid-fuel version doesn't work either, because it barely covers the energy used to farm it and we need the land for growing food instead.)

The problem, as ever, is basically down to stupid politicians who can't understand that allowing a negligibly small amount of coal mining to run a few old steam engines is indistinguishable for all practical purposes from allowing none whatsoever as their ill-considered obsessions dictate, and need to spend some time sitting in the room with the guys with rubber hoses until they cease to dispute this obvious point. I and others on here have pointed out that a small-scale coal mine itself would have "heritage tourist attraction" value in the same way as the railways it would be supplying do, and the two operations could operate in collaboration; we still at present have enough remaining knowledge and enthusiasm to start it up and teach people how to carry it on, if only the politicians would allow it to happen.

 

[AlastairFraser]

It is true that extracting a decent percentage of the heat from the flue gases during their notably short passage through the tubes is a major source of inefficiency for a conventional steam locomotive. But I don't think anyone's suggesting just putting a heater where the fire used to be. The Swiss experiment used a great big immersion heater in the boiler, and that is surely the obvious way to do it.

And as has been pointed out, it's still nowhere near good enough.

The most effective "steam battery" technology that has been tried is to use the latent heat of solution/dilution of sodium hydroxide. The boiler has separate sections for water/steam and NaOH. After the steam has passed through the cylinders, instead of being exhausted it is led into the NaOH tank, where it interacts with the NaOH to release more heat to raise more steam. To reset the system you squirt hot dry steam through it, from an external source heated by anything you want, same as an ordinary "fireless" locomotive but with greater range.

This has a range of several miles, so it might be usable by the shorter steam railways by converting some of the locos from classes of which a disproportionately large number have been preserved. Might. But with no steam chuffing out, it kind of ruins the whole thing, so probably not.



Don't be misled by the propaganda emitted by those crusty stains at Drax and their ilk. Biomass is a stupid option for power generation. Obtaining it from trees grown in remote areas half way round the world means the tree end operates pretty much entirely without supervision or enforcement, so the "sustainability" can be faked with outright lies and with vapourware promises for what they'll do in 20 years' time which they can then deliberately go bust to get out of, before restarting under a different name. They don't even have to try very hard, because everyone knows that plants grow themselves therefore they "must" be sustainable, and next to nobody thinks any further about it. And that's without considering the lugging of it half way round the world in ships burning fossil fuel. It's not "green", it's just (rather too effectively) greenwashed.

(The short-term liquid-fuel version doesn't work either, because it barely covers the energy used to farm it and we need the land for growing food instead.)

The problem, as ever, is basically down to stupid politicians who can't understand that allowing a negligibly small amount of coal mining to run a few old steam engines is indistinguishable for all practical purposes from allowing none whatsoever as their ill-considered obsessions dictate, and need to spend some time sitting in the room with the guys with rubber hoses until they cease to dispute this obvious point. I and others on here have pointed out that a small-scale coal mine itself would have "heritage tourist attraction" value in the same way as the railways it would be supplying do, and the two operations could operate in collaboration; we still at present have enough remaining knowledge and enthusiasm to start it up and teach people how to carry it on, if only the politicians would allow it to happen.

Biomass doesn't have to be obtained from halfway round the world - sustainable forestry in the UK would be a good source.
It again is just a question of time, money and will; same as your small scale heritage coal mining operation.

 

[Backroom_boy]

Oil has been used in the past in the UK and wood burning was common in some other countries. Would a typical heritage (for the sake of discussion consider something small like an 0-6-0T and a larger loco like a 4-6-0 5MT) steam loco be able to operate on wood as fuel with minor modifications? Would you be able to maintain sufficent boiler pressure in use? What about sparks and ash, wood ash is much finer and flies around. Wood is readily available and is renewable. Bear in mind we are doing 25mph and at most 20 odd miles, and in a lot of cases less.

I was watching an episode of Thomas the tank engine, (called I think 'Thomas and the forest engines') where the whole 'plot' was wood burners had last less range than Thomas due to wood being less energy dense. Obviously I get all my kettle tech knowledge from Thomas....

 

[eldomtom2]

The problem, as ever, is basically down to stupid politicians who can't understand that allowing a negligibly small amount of coal mining to run a few old steam engines is indistinguishable for all practical purposes from allowing none whatsoever as their ill-considered obsessions dictate, and need to spend some time sitting in the room with the guys with rubber hoses until they cease to dispute this obvious point. I and others on here have pointed out that a small-scale coal mine itself would have "heritage tourist attraction" value in the same way as the railways it would be supplying do, and the two operations could operate in collaboration; we still at present have enough remaining knowledge and enthusiasm to start it up and teach people how to carry it on, if only the politicians would allow it to happen.

I think the more relevant question is whether or not said "heritage coal mine" would be financially viable...

 

[HSTEd]

The problem, as ever, is basically down to stupid politicians who can't understand that allowing a negligibly small amount of coal mining to run a few old steam engines is indistinguishable for all practical purposes from allowing none whatsoever as their ill-considered obsessions dictate, and need to spend some time sitting in the room with the guys with rubber hoses until they cease to dispute this obvious point. I and others on here have pointed out that a small-scale coal mine itself would have "heritage tourist attraction" value in the same way as the railways it would be supplying do, and the two operations could operate in collaboration; we still at present have enough remaining knowledge and enthusiasm to start it up and teach people how to carry it on, if only the politicians would allow it to happen.

The coal from such an operation would be ruinously expensive for the scale required.
The only way to even approach viability for such an operation would be an open cast "coal quarry" - which doesn't really have that much heritage value. It would just be a hole in the ground.

 

[WAO]

I don't think that there's any mileage in immersion heaters in boilers and pantographs on tenders - the thermodynamics are all wrong.

What might be possible is a LNG/CNG (Methane) tank in the tender. The gas burner would be automatically controlled (no fire-person needed and firing up would be via timer, while the driver was still in bed) and would turn down easily, which a solid fuel fire could not. Also, the gas flame would be gentler on the combustion chamber/firebox than an intense carbon fire, prolonging life. The higher unit cost would be defrayed by other savings at least in part.

WAO