back to article 'Biocoal' fuels steam train comeback

Trainspotters who find the homogenized world of modern locos a bit dull could soon be celebrating the return of steam, if all goes well in a University of Minnesota study. The university, along with Sustainable Rail International, are to restore a 1930s locomotive – 3463, a 4-6-4 Hudson-type loco built by Baldwin that’s spent …


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  1. wim

    processing process

    cellular material processed into a solid fuel

    did they say how much energy is needed to process the cellular material into a solid fuel ?

    I love all the green talk about how alternative fuels seem to magically appear without any energy cost.

  2. Anonymous Coward
    Anonymous Coward

    My first thought

    How is this "clean" biocoal produced and how much energy is required?

    1. Voland's right hand Silver badge

      Re: My first thought

      Same way as charcoal - dry distillation of organic matter.

      1. The dry distillation produces most of the nasty stuff (sulphur, nitrogen, etc from proteins go at that stage as sulphur dioxide, etc). What is left after that is nearly pure carbon. It can burn very clean. The problem with it is that it is very porous, takes lots of space and its energy density is a bit crap. That can be solved by pressing it into small pellets ("high density coal").

      2. While making biomass into coal requires some energy to start off with it can be made self-sustaining as a side project of partially burning the biomass. Just ask any of the cough, cough, national minorities stripping to bare ground the woods of Eastern Europe and making them into charcoal for sale.

      3. As far as a modern steam train having efficiency on par with diesel - that is a given. Steam is not that inefficient. The problem with steam is not the efficiency - it is the maintenance bill. All that regular boiler descaling, cylinder overhauls, gasket changes, etc cost a pretty penny. Add to that having to have regular (and probably in this day and age deionised) water supply along the rail lines. Compared to that with a diesel you just change the oil and the oil filter every few thousand miles and keep filling it up with some rotten dinosaurs.

      1. JimC Silver badge

        Efficiency on a par with diesel??

        Are you sure about that? I always understood that the thermal efficiency of steam locomotives was pretty diabolical.

        By far the most efficient use of their biofuel would be to burn it in a power station for electric trains, but that wouldn't get them any headlines.

        Mind you historically the biggest challenge isn't so much getting your steam engine up to 126mph, which is at least partly a question of finding the right hill, as producing a design that doesn't destroy its centre big end bearing *every* time it gets up to about 120mph...

        1. MJI Silver badge


          Bearing issues were sorted very soon after.

          The NRM has even stated that if the world speed record got taken, they would restore Mallard and go for a higher speed.

          If it wasn't for speed restrictions Mallard could have hit 130mph

          A4s could easily cruise at a ton. And the German run was a lot lighter.

        2. ukgnome Silver badge

          Re: Efficiency on a par with diesel??

          Half right - the most efficient way would be to burn the biocoal in the train, produce steam and convert into electricity using a steam turbine. A sort of steam electric rather than a diesel electric.

          It's not a new idea, the use of steam to generate electricity is quite old, but adding a steam turbine and doing the converting of energy on the rails is (i think)

          Just look at is as a massive Mamod project and scale up - my laptop has a running time of five mins on a full steam (using 2 mamod traction engine boilers and a dynamo) If I applied a bit more science and stored the wasted energy I think I could manage about 15mins. Whilst the initial cost is installing the batteries for storage is a little bit high, as well as all the other gubbings. But over time that cost looks after itself.

          1. JimC Silver badge

            Steam Turbines

            AIUI the problem with steam turbines was always flexibility: they have a relatively narrow range of rotation speeds where they operate at peak efficiency. Back in the 40s they found that if the set the thing up for peak efficiency at peak power then it was horrendously inefficient at normal speeds, and if they set it up for peak efficiency at normal speeds it was down on power and efficiency at the top end, and they never solved the problem.

            Assuming that's still the case, which seems likely, then the problem still stands when developing an electric transmission. The only way would be to store surplus power for when needed, which would either mean dragging round many tons of batteries, or else having some kind of "feed in" of extra power into a "grid". And of course if you have the grid then there's no point in hauling your own generator set about anyway.

        3. itzman

          Re: Efficiency on a par with diesel??

          thermodynamic efficiency is very much a function of the ratio between working fluid (steam) peak temperatures and the exhaust temperature (in degrees absolute).

          A steam power station struggles to reach 36% with supercritical high temperature steam and heavily condensed low pressure turbines at the arse end.

          From memory no steam locomotive ever achieved much more than 20%, and most were less than 10%.

          Gas turbines - jet engines and so one - get to about 37% by dint of higher combustion temperatures as do some high efficiency diesels.

          The best place to burn coal or biomass is in a power station where the bulk of the condensers is not a drawback. And likewise the scrubbers to remove ash and other noxious elements from the exhaust.

          Its an amusing project, but its not a serious contender:

        4. Nick Galloway

          Re: Efficiency on a par with diesel??

          I seem to recall that a few chappies a little over a century ago demonstrated this 'new' highly efficient engine loosely described as an internal combustion engine. It was demonstrated to be significantly MORE efficient than steam (or external combustion) engines. It makes damned all difference as to the fuel (other than internal combustion engines don't tend to process chunks of coal all that well) as you will get better mileage with a litre of petrol in an internal combustion engine than with a steam type external combustion variety.

          All this coming from the country that brought us the atomic age. Someone seems to have lost out on some fundamentals somewhere!?

          1. Mike Richards Silver badge

            Re: Efficiency on a par with diesel??

            'All this coming from the country that brought us the atomic age'

            I think you're on to something - how about a nuclear-powered steam engine?

            1. John Brown (no body) Silver badge

              Re: Efficiency on a par with diesel??

              "I think you're on to something - how about a nuclear-powered steam engine?"

              Only if it also flys! Oh, and time travels when you hit 77mph.

              Mines the one with the flux capacitor in the pocket.

            2. MJI Silver badge

              Re: Electric steam engine

              With kettle style elements

              IT HAS BEEN DONE!

          2. MJI Silver badge

            Re: diesel effiency

            I read somewhere the record was 50% efficient. Not sure if that was overall or just the lump.

            Class 60 anyway - the last British built Diesel locomotive

            <- sad at death of another industry

      2. Anonymous Coward
        Anonymous Coward

        Re: My first thought

        "keep filling it up with some rotten dinosaurs."

        How many Miles Per House of Lords do you get with that?

  3. Denarius Silver badge
    Thumb Up

    at least the technophobes will complain less, maybe

    at least deforestation is easy to fix, given the large area of farmland being abandoned in north america. Moderate reversion of grassland to forest elsewhere would also help, if one can ignore the techno-fudists who ignore the creation of grassland by large scale burning by humans destroyed forests in preliterate times.

  4. publius

    The problem is . . .

    Steam engines were retired because of the stupendous cost of maintenance. They required continuous, intensive maintenance, and needed total rebuilds far more often than diesel-electrics. Modernized fuels might fix one of their problems, but these old machines will not be cost effective.

    Sad. I would love to see them come back.

    1. Anonymous Coward
      Anonymous Coward

      Re: The problem is . . .

      And... The 3%-6% efficiency of the engine and the fact that with an electric, diesel or diesel-electric, when you finish for the day, you just turn it off, you don't have to wait for it to cool down and rake out all the ash.

    2. david 12 Bronze badge

      The Real Problem Is...

      Steam engines don't share the torque between the wheels like Electric Motors do.

      If one wheel slips on a Steam Engine, all the torque and all the power and all the load goes to the other wheels, which then break traction and the whole engines is spinning it's wheels. To stop this, steam engines use sand (or even gravel) on the track, and must be heavy in proportion to their power. Which means they must be very heavy, and the track and bed must be very expensive.

      If one wheel slips on a (Diesel) Electric, the torque to that wheel is automatically reduced only enough to so that it is not slipping. Load is not flung suddenly onto the other wheels, the engine can be cheaper and lighter, and the road-bed can be cheaper and lighter.

      Furthermore, the Diesel Electric engines can be strung together and all share the load correctly. This never worked very well with Steam Engines: it works very well indeed with Diesel Electric.

      This is not some magical digital control system, it is just the characteristic of the kind of electric motors that are used in Diesel Electric trains, the torque is proportional to the phase angle.

      If fluidized coal becomes very cheap, we might see some Turbine-Electric trains. We won't see the 'return of steam engines' because they aren't very suitable for pulling trains.

  5. stucs201

    Choo choo!

    Taking on the steam train speed record? That I approve of, records are there to be broken.

    1. graeme leggett

      Re: Choo choo!

      Will it be pulling seven coaches (250 tons) when it tries.

      1. Anonymous Coward
        Anonymous Coward

        Re: Choo choo!

        Just look at Mallard, then this, which do you think is going to go faster?

        1. MJI Silver badge

          Re: Faster

          The A4 of course

          1. IvyKing

            Re: Faster

            I'd bet on the AT&SF Hudson - similarly design loco's used by the Milwaukee (Baltics on the CMStP&P) were hitting 105 - 110 MPH in regular service while pulling a much heavier train than the Mallard on its record run. The Pennsy T-1 would almost certainly be faster, there were reports of it hitting 125 MPH in service.

            1. imanidiot Silver badge

              Re: Faster

              I doubt the reports of the americans. The speeds they are claiming are way outside the horsepower curve of those locomotives. They couldn't even theoretically hit those speeds, let alone in practice. The germans with their 05 class were normally pulling heavier loads (Although not on the day of the highest recorded speed, as 50 tons had been dropped), on longer runs ON FLAT GROUND at speeds very close to those of Mallard's record.

              Mallards record is somewhat disputable with a sudden surge in speed at a point where the track was at a constant gradient.

              See this site for reference: (Don't mind the amateurish page design though, it's a bit cringe worthy)

              The biggest drawback on steam locomotives wasn't efficiency (The early diesels cost much more in terms of running cost) but diesels saved a LOT in terms of maintenance. Not just in the loco itself, but just getting it fired up and then keeping it warm between runs.

              Any mechanical engineer that has ever been on the footplate of a steamloco can probably attest to the fact that steam loco's are the closest to a living thing ever built. They are like women, listen carefully and treat her nice and she tells you everything you need to know to keep her happy. Then every once in a while they will have a day where they try to bite your head off for even the slightest of mistake no matter what you do to appease it.

              While I would love to see the "old" type of steam loco return to service, I don't see this happening any more. The needed infrastructure and added maintenance costs are just not going to let this work.

              Now where is that crotchety old geezer icon... (And I'm only in my mid 20's :-( )

              1. IvyKing

                Re: Faster

                The Milwaukee speeds were from timings aboard regular runs of the Hiawatha between Milwaukee and Chicago. While the peak DBHP occurred below 100 MPH. the loco's were still putting out a significant amount of power. One limitation for the top speed of steam locomotives is dynamic augment, which is lessened with 84 inch drivers and just three coupled axles on the 3463.

                As far as the Pennsy T-1's, the design spec called for 100 MPH with 1,000 trailing tons.

                Also bear in mind that larger American loading gauge allows for larger boilers - with the gas flow area being critical for power production.

  6. Anonymous Coward

    eco-wank alert

    I'll post the same comment I put on gizmag where this surfaced there last week. Firstly all coal is bio-coal by definition and secondly, carbon neutral refers to removing the same amount of carbon from the atmosphere that you put in. It does not refer to putting in the same amount of carbon that the original biomass (allegedly) took out.

    If you read the original blurb you'll find this comes from the University of Minnesota's Institute on the Environment, not the Physics or Mech. Engineering departments (who probably react to this announcement somewhat like a well known Kryptonian does when faced with green rocks).

    Oh and Richard gets a provisional -1 for lack of attribution (to be withdrawn if he shows that this article isn't a retread).

    1. frank ly Silver badge

      Re: eco-wank alert - carbon neutral definition

      If i grow a tree from a seed, then cut it down and burn it, surely that is carbon neutral as well? The thing is, I have taken action that causes the tree to exist in the first place........ It gets complicated.

      (P.S. It's jizzmag that has all the wank stuff in it.)

      1. Anonymous Coward
        Anonymous Coward

        Re: eco-wank alert - carbon neutral definition

        @ Frank ly - (P.S. It's jizzmag that has all the wank stuff in it.) Yes it does which is why I'm surprised to see el reg leeching from it.

    2. Anonymous Coward
      Anonymous Coward

      Re: eco-wank alert

      "Firstly all coal is bio-coal by definition "

      Fair enough.

      "It does not refer to putting in the same amount of carbon that the original biomass (allegedly) took out."

      Why not? Sounds neutral to me; the nett change of C in the atmosphere is zero. Also, "allegedly"? What are plants made of where you live?

  7. Anonymous Coward
    Anonymous Coward

    Flat Earth Society

    Down with this kind of thing!

    What will be next, dinosaur saddles?


  8. Richard Ball

    Title says it all

    They've called it "Project 130". i.e. We want to make this thing go at 130 miles an hour.

    What are the chances there's an academic behind all this with a healthy but misplaced obsession with steamtrains? His senior university job has given him some influence he's found he can twist into a subsidised steamtrain-restoration club.

    I really ike the fact that people restore / recreate and run these things - but to do so in the name of efficiency, speed and the environment? Bollocks.

    On the fuel conversion process: it may well be self-sustaining, but so it leaving your car idling all night. You chuck away half the energy you could have made use of.

  9. getaclue


    I always wondered what a modern steam engine might look like. Today we have the technology to solve the high maintance problems, including the issue of dynamic inbalance hammering the tracks to death. But, I wonder if any new designs could actually be approved and built in todays world?

    1. Dave Bell

      Re: Amusing

      There are several problems with high speed steam engines of the traditional sort, including the "hammer-blow" on the track from the rotating balance weights needed by the reciprocating mechanism. I doubt they'll be able to find a line in the USA on which they will be able to run a steam locomotive at that planned speed.

      There was research in the late Seventies on "fluidized bed furnaces" and some paper designs were produced for locomotives. There was one with a Garratt layout that used steam condensers, and a few patents were issued. These days, turbo-electric transmission might be usable. There has also been a lot of development in boiler technology and operation since the 1950s.

      Putting it bluntly, this all looks like a dead end. At best, it will be a solid base for comparing the fuels, because of old data on the locomotive class, burning coal.

    2. Anonymous Coward
      IT Angle

      Re: Amusing

      Try looking here

      There are several areas where 'Advanced' steam has been taken well beyond where British main-line steam ended in the 1960's (and most of North American steam locomotion several decades before that).

      Having said that, I think that there are too many obstacles relating to infrastructure (water supply for one) and maintenance that would make a return to steam non-viable in the 21st Century as a front line method of mainline traction.

      And the I.T. angle is ... ?

    3. itzman

      Re: Amusing

      The optimal way would be to do the equivalent of a CCGT power station. Blow coal dust into a compressed airflow and ignite it on a continuous basis and run it through a turbine, and then through a secondary steam cycle.

      BUT the point remains, why bother?. Better to drive a genny in a fixed plant and use leccy locos instead.

  10. Anonymous Coward
    Anonymous Coward

    full rake

    Unless its an in-service mainline locomotive with its 7 coaches, the record will not be recognised by Guinness. Mallard was a streamlined loco, no matter what Biofuel in the boiler the steam pressure required is very difficult to achieve for an external piston design....I think the record is safe probably for another century....that said if someone tried to create a Steam turbine, now that possibly could get the record.

    1. MJI Silver badge

      Re: Streamlined

      Also streamlined internally - smoothed passages ect

  11. Tony Reeves 1

    Hell That's Fast

    Having been on the foot plate of a Ja class loco in NZ, going down a slight gradient at an indicated 70mph I would not want to be there at 130mph. 70mph was like the gates of hell, noise, fire, smoke, swaying (we only have narrow gauge). I only really enjoyed it because I was well primed with alcohol. I think the driver was as well.

  12. Steve Davies 3 Silver badge

    US Loco Design

    Is more brute force than anything else.

    There were many improvements to stem engine design after this loco was built. Most of those came in Europe. Improvements to chimney and blastpipe design. Radical changes to the valve gear. etc etc

    If you have ever travelled behind BR 71000 Duke Of Gloucester over the Settle & Carslile you will know what I mean. Going from a standing start in Appleby(going south) to 70mph with 12 Mk 1 coaches behind it and climbing all the time up to Dent box was a real pleasure.

    If I were thinking of doing this then just about the last engine I'd start with would be one of these. A NYC 4-8-4 Streamliner perhaps. They could easily top 100mph in service even with crap W. Virginia coal.(crap when compared to S. Wales Anthracite that is)

    Ok, mines the one with a Greasetop in the pocket.

    1. graeme leggett

      Re: US Loco Design

      Going by some freely available data

      Mallard, 158 kN on 167 tonnes (with tender) - 0.95 kN/tonne

      Milwaukee Road class F6 4-6-4 203 kN on 241 tonnes - 0.84 kN/tonne

      (streamlined) F7 class 4-6-4 - 224 kN on 360 tonne - 0.64 kN/tonne

      Not sure if that shows anything other than aerodynamics is important.

      1. graeme leggett

        Re: US Loco Design

        It seems that the loco in question is a ATSF 3460 class

        Tractive effort - 220 kN

        Weight with tender - 323 tonnes

        0.68 kN per tonne

        What may account for the difference is the tender weight, for a long journey a large tender and large coal and water supply is required

        recalculating "output" excluding tender weight

        Mallard - 1.45 kN/tonne

        ATSF 3460 - 1.17 kN/tonne

        1. Mips

          Re: US Loco Design

          Aaaahnd - the wheels aren't as big.

          Do you remember when Edward was dragged along by Gordon children?

          1. MJI Silver badge

            Re: US Loco Design

            5 foot wheels can do 90mph

            Quite successfully.

            Much to the suprise of senior railway staff.

            Freight engines are not suppossed to be capable of express train speeds. But the 9F could.

  13. Caff

    Given the amount of hassle it would be to run the steam loco compared to a desiel it might be better for them to use to coal in a normal power plant to provide power for an electric train system.

    1. Anonymous Coward
      Anonymous Coward


      A nationwide 'Electric Train' system in the US? Who are you kidding?

      There is only one part of the US Mainline network that has electic trains and that is the Washington DC, New york, Boston corridor and not all of that is electified. Even that was threatened with being switched off not all that many years ago.

      Raising the idea of stringing Catenary across the great plains is just laughable. Remember that 90%+ of all traffic on the rails is Freight not passenger as in other parts of the world.

      Whilst your proposal has some merit it is a non starter.

      and yes, I know about the Trans Siberian but even that is not leccy all the way to Bejing.

  14. Chris Miller

    Surely a modern 'biocoal' steam loco would be a turbine, of which several examples were built. No hammer blow problem, but no reverse gear either (needs a second turbine which increases costs and doesn't help the power/weight ratio).

    1. TRT Silver badge


      Yes, the Turbomotive. Sadly wrecked at Harrow & Wealdstone and rebuilt as a standard piston type. If you go through Harrow & Wealdtone, you can see the over-bridge is not riveted in the centre section where it had to be rebuilt after the crash. A mess that was.

      I can't see this project hitting its goals, though.

      1. Anonymous Coward
        Anonymous Coward

        Re: Ah...

        Actually no. It was the other way round. The Turbomotive (LMS 6202, BR 46202) was first rebuilt as a conventional locomotive and was then wrecked in the crash at Harrow and 1952.

        It is widely understood that the loss of 46202 (named 'Princess Anne') led to the decision that one class 8P locomotive could be added to the Riddles designed BR standard programme. And so Duke of Gloucester (71000) was authorised. Many debates on how effective and efficient 71000 was in its BR form and post preservation a number of flaws in the original build have been addressed - or not depending on your bias / point of view.

    2. ZanzibarRastapopulous

      Surely turbo-electric would be the way to go?

      1. Chris Miller


        You may be right, but it adds another layer of complexity and efficiency loss.


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