If someone was to create a steam locomotive with today’s technology, what would it look like?
If the designers were smart, they would probably end up with designs similar to the ones near the end of the steam locomotive age. New technology does not always mean better. Better materials yes, but better ideas? Better concepts? Probably not. Remember the beginning of the space age? The return capsules were simple. The newest designs for the next generation of US space capsules is almost identical to 1960’s era tech - just bigger and different materials.
The problems of emissions controls would really affect the design. I suspect that coal fuel would be out, and a rather complex oil firing system would be required.
Jim
I tend to think that they could use adaptions of the engine–>generator–>traction motors base design of most Diesel-Electric locomotives out-there. Heck, keep things modular enough, in theory you could use any power unit that uses any source of fuel that can run the generator and drive the wheels (for non electric locomotives)
I don’t think you’d want designs with external piston rods direct-driving the wheels (pretty much the traditional design of steam locomotive - although admittedly the cool reciprocating action does makes a steam locomotive rather interesting - as AFAIK rather heavy steam locomotives really pounded the heck out of the rails - ah, the wiki entry calls it “Hammer Blow”
A rod-driven locomotive could employ the Withuhn modifications to greatly reduce the dynamic augment - what that Wiki entry was referring to. It would also be possible to incorporate ideas from Andre Chapelon (improved steam flow and exhaust ducting) Porta (gasifier firebox) and others to improve and clean up the steam generator (boiler.) Control of stack emissions might require a whole new level of inventiveness, but it can be done.
The one thing I wouldn’t expect would be a resurgence of the steam turbine electric. The operating characteristics are fine for constant speed but suffer badly when the speed departs from the optimum. Also, unless locomotive suspension systems have improved almost beyond belief, the operating environment is far from ideal. Turbines are good in fixed power plants and aboard ships, but only a ship in combat begins to approach the abrupt movements ordinary slack action can impose on a locomotive.
IMHO, the biggest obstacle would be financial. Initial development and prototyping would swallow $$$, with no guarantee that some future Congress will never chop the idea off by legislative fiat. Or some mad scientist might team up with a sane engineer and perfect a little box that eats used cat litter (or anything else equally worthless) and produces 650VDC, ready to feed to the AC drive controllers and the skewed squirrel cage traction motors.
Somehow I think that change, when it comes, will come quickly - and from an unexpected direction.
Chuck (sometime SF author)
No steam-turbine-electric? I don’t know, the Norfolk and Western’s “Jawn Henry” got pretty close. It did have its bugs, but those could have probably been worked out if the experiment had been continued.
But it wasn’t. Missed opportunity? No, not with diesels coming anyway.
Withun has that proposal for a “conjugated duplex” that required a pair of crank axles, although it is argued that this linkage between the two sets of drivers would not be called upon to transmit the full torque, just enough torque to keep the two sets of drivers rolling the same way.
The Pennsy S-2 turbine had quill drive to one or two drivers and then siderods to the others, and siderods without having to balance reciprocating forces was not that bad an arrangement. I believe a Swedish turbine had a jackshaft drive as used on many of the early electrics before they made the motors much smaller. The turbine turned a dummy driver, and that driver was linked to the real drivers contacting the rails with siderods, and that too did away with the reciprocating forces.
I have been wondering of a high-speed multi-cylinder steam piston engine could be coupled to the wheels with that same electric-locomotive style jackshaft drive. Actually, this invention is credited to Thomas Crampton, of the “big wheel” steam engine that was popular in mid 19th century France for express
I would not be surprised if they looked very much like diesel locomotives do today. When the turbines showed up they were very similar to diesels of that time, the exception of course being the PRR version.
I thought so too, until I read Louis Newton’s book. The turbine-electric part was the disaster, apparently, with improperly-designed auxiliaries being a contributing factor. Sure, all those details could still have been fixed, but you’d still have only a 4500 hp constant-power locomotive, incapable of making substantial power at high speed, and probably reflecting a tradeoff between limited power at instantaneous/hourly rating at low speed vs. traction-motor longevity.
Minimum modern design size for a turbine-electric under modern conditions is nearly 9000 hp. The B&W water-tube boiler will not scale to that number; in fact, according to Tom Blasingame (who ran the numbers) it won’t even scale cleanly to 6000 hp without detail redesign.
I still think there is a place for mechanical-drive steam turbine power… but a limited and circumscribed one.
In my opinion, a “modern” steam locomotive will either resemble a longer version of the FRA ALPS locomotive (with a gas-turbine combustor feeding a combined-cycle steam bottoming plant) or will use ultrasupercritical steam motors (again with extended Rankine-cycle heat recovery bottoming). Neither of these will use ‘conventionally’ recognizable boilers, although I do expect them to use some form of condensing or Holcroft-Anderson ‘recompression’, and take other measures to minimize the effective water rate (for the purified water used in high-pressure cycles).
There may be a place for ‘second generation steam’ using a more-or-less familiar reciprocating configuration. I would NOT expect this to follow the wonky premise of the ACE that steam has to be ’
Well boys, you know steam engines ARE being built today by the Kloke Locomotive Works.
However, they look like something from the 1860’s!
Better than no new steamers at all!
Should I start a new thread on “combustion processes” or would that result in the TLDR and MEGO effects?
I was doing some Web surfing on “boilers” and “coal combustion”, kinda to see what the “rest of the world” is doing when they want to burn solid fuel to raise steam.
It isn’t just trains, ships of various kinds, with the possible exception of the SS Badger lake ferry that is not only steam, it is reciprocating steam, and I don’t get a whole lot of love for mentioning this, the EPA, motivated by every environmental group, is breathing down their neck about discharge of coal ash into Lake Michigan. Yes, people drink the water and catch the fish, and I have done all of those things and yes, they should figure some way to not dump the ash, but that the SS Badger is the last of its kind and a piece of our industrial heritage doesn’t influence some people. Heck, when the Soo 1004 last came to Madison, there was a torrent of angry letters-to-the-editor about the environmental damage.
So steam propulsion is really almost gone, everywhere, so who needs a boiler? Well, there are still a lot of coal-fired electric power plants, and even those new high-tech gas-turbine gas-fired plants use “bottoming cycles.” OK, who else.
It seems that everyone and anyone who wants to burn some fuel “over here” in order to supply some heat “over there” uses boilers to raise steam – central heating plants as for campus buildings at the “U”, various kinds of commercial and industrial applications, and so on. So boilers of
Paul Milenkovic:
“I have been wondering of a high-speed multi-cylinder steam piston engine could be coupled to the wheels with that same electric-locomotive style jackshaft drive.”
I am no expert on steam engines, and I don’t know much about the details of how pneumatic tools work, but your mention of a high-speed multi-cylinder steam piston engine got me thinking. I’ve long been impressed with the speed and power of pneumatic tools in such compact packages. What about the equivalent of pneumatic drill motors (much bigger, of course) driven directly by steam and geared to the drivers, much like electric motors are?
So, what is the combustion system of a steam locomotive, and what difficulties does it have?
A steam locomotive burns coal fuel on a firegrate at the bottom of a waterwall firebox. One problem is putting fresh coal on the grate to feed the fire. Owing to the high combustion rates and high rates of drafting of the combustion air required for the compact boiler on a steam engine, in relation to its heat rate, you have to get the coal spread evenly. If you get thin spots, cold air comes through and it does bad things to your boiler like cause differential contraction of tubes that cause water leaks, very bad.
One solution is to have a skilled, able-bodied crew member, the fireman, shovel the coal onto the grate. A second solution is to have a steam-driven stoker sprinkle coal on the grate. You still need a crew member to operate the stoker and keep an eye on the boiler pressure and water levels and anticipate changes in steam demand by seeing what the engine driver is up to, so you don’t clog the fire, allow thin spots instead to develop, waste steam by popping the safety valves when the pressure limit is reached, stall out on the road by letting the pressure drop, and yes, kill yourself and your driver by letting the water-wall water level drop that the firebox overheats and blows everything up in a water-flashing-to-steam explosion.
You also have to remove ash from the firebed so it doesn’t choke the fire. That is done by 1) letting the ash simply fall through the cracks between the firebars and fall into the ashpan, 2) agitating (rocking) the grate with a handle-driven link to encourage the ash to fall into the ashpan, 3) dumping all or part of the firebed into the ashpan using that handle and starting over with a fresh fire with fresh coal.
On top of all that, if your fire is hotter than the coal-ash melting (fusion) temperature (the coal ash is actually the non-combustible rock mixed in with the coal as they mine it, and that rock
It would look like this:http://www.5at.co.uk/
I too have wondered about steam motors driving individual axles.
My office neighbor from a couple years back taught the course on electric drives, and he did research on electric drives of the type his industrial employer used in airplanes. These direct electric drives are meant to replace the “wet” hydraulic system in airliners and their high maintenance expense. He thought that electric drives will “replace everything” and I tried to educate him about the need for quill or even Cardan shaft mechanical drives, from the electric motor, to reduce track impact in high-speed trains.
At least with an electric motor, you just need to supply a pair of wires, and if those wires are thick enough, which is usually not a limiting factor, those wires can bend as needed around corners.
With steam lines, you have both heat loss as well as fluid resistance to worry about when you start running steam lines all over the place. In the usual 2-cylinder rod-drive steam locomotive, you have short and fixed steam lines and exhaust lines, and it is fairly easy to make them low heat loss and low fluid resistance.
The minute you go to a divided drive of any kind, articulated locomotives are a simple version of the steam motor idea, things get really complicated really quickly. I just returned the book on the H-8 Allegheny to the State Historical Society library. The 6-drivered Alleghenies replaced a fleet of 5-drivered plus trailing truck single-axle booster locomotives that the railroad assigned the same tonnage rating. The divided-drive Allegheny with two 3-axle engines may have pounded the track less than the single 5-axle engine, but hoo boy did you have steam pipes going ever
The Porta Gas Producer Combustion System (GPCS) was mentioned – what does it do and how does it work?
According to Wardale’s Red Devil and Other Tales of the Age of Steam, the problem with lump coal combustion on a firegrate, the standard steam locomotive system, is that as the lumps burn down, they get entrained by the flow of combustion air coming up from the bottom through the grate, and they are swept out as “sparks and cinders” through the boiler tubes and out the stack. Besides setting lineside fires (a problem in arid South Africa), the “carbon carryover” makes everyone’s clothes dirty, and it is a substantial waste of fuel. At the “grate limit”, fully 50 percent of the fuel goes up the chimney, contributing to the very low thermal efficiency of steam engines. If you could prevent carbon carryover, theoretically you could double overall thermal efficiency.
The Gas Produces system operates with a thick firebed and a greatly restricted flow of “primary” combustion air coming up through the grate. The idea is that such an oxygen starved fire turns coal into hydrogen and carbon monoxide, especially if some spend exhaust steam is fed into the firebed. That hydrogen and carbon monoxide then ignites when “secondary” combustion air is introduced above the grate.
That is how it works. What it is supposed to do is greatly reduce the carbon carryover problem. Because the primary air is greatly restricted so the coal bed doesn’t as much as burn but acts as a “gas producer”, there is much less force trying to lift the particles in the coal bed out the chimney. So the “gas producer” is not that you are turning the coal into gas to have a gas fuel. Rather, you are trying to combust the coal in two phases – the first phase of solid coal in contact with restricted combustion air to produce combustible gas, and the second phase of the gas rising from the firebed bu
Wasn’t there an accompanying artist’s conception of what Ross Rowland’s C&O 614 would have metamorphosized to if those ACE 3000 experiments proved out?TRAINs mag, decades ago?
A cab-forward 4-8-4, somewhat covered-wagonish-looking, EMD F-unit cab?
I’ve seen the artist’s conception. It looked like a cross between an SD-70 and a Pennsy T-1, that is a modern cab unit with a duplex running gear. I’ll see if I can find a picture somewhere.
OK, here ya go…
If it were an oil burner it would be a variation of the SP cab forward locos. Probably have a EMD or GE style collision posts and nose . With the smoke stack behind much better for tunnels.
A coal burner might be built the same way but it would take a very long stoker system to provide coal to the front of the cab for the firebox. certainly have MU cables for diesels behind and or a second unit. . Smokestack of first unit would be close enough to second unit to drive smoke and cinders over cab ?
Since most CP and yard turnouts are designed today ffor diesels a more practical arrangement might be a 4-8-4 or a 6-8-4 ? A 4-8-8-4 would be severely limited as to where it could operate + the size of turntables or wyes.
Not to ME!!! ;-}
There’s more to it than this, including the type and configuration of boiler that works best with this (and with the Cyclone variant of solid-fuel firing). Part of the story is very large size; part of the story is long-period stable operation at baseline load that requires little if any turndown from design conditions; part of the story is lots and lots of packaging space for aftertreatment, air preheat and economizer operation, etc.; part of the story is generally easy access to AC power to drive auxiliaries/ancillaries… electric motors generally being much more effective than small turbines or whatever.
One reasonably successful method of pulverized-coal firing on locomotives was the version of StuG that was tested on Victorian Railways. As you know from reading the Red Devil, Wardale thought that the next logical step beyond GPCS was some variant of PulC firing… I would argue with some intermediate-size fuel form factor, larger than conventional pulverized ‘fines’, but probably not as large as the ‘pellet’ size for some of the torrefied additives. There are still some difficulties involved with flameholding, the extreme turndown ratio endemic to normal railroad operation, etc.
With regard to operation of GPCS:
Well, not exactl