If someone was to create a steam locomotive with today's technology, what would it look like?
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
Modeling BNSF and Milwaukee Road in SW Wisconsin
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.
chutton01 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"
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 passenger trains.
But is the hammer blow and "dynamic augment" really that big of a problem? There were undoubtedly cases of some small-drivered 2-10-0 or 2-10-2 with bad balance to begin with, run too fast downgrade and damaging sections of track. Everyone keeps saying that the "steam locomotive pounded the rails", but if it were such a problem, wouldn't 3-cylinder and 4-cylinder "balanced drives" using cranked axles been much more popular?
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
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.
Firelock76No 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.
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 'hidden' to be taken seriously in a modern context. On the other hand, a very clear and detailed case, showing all the ancillary details, would need to be made for this kind of power if it is to be competitive with modern diesel-electrics, or straight electrics in those areas where the necessary power infrastructure can be built. Very little has changed since the Porta SGS designs, and David Wardale's Red Devil, were made.
I am not a particularly strong supporter of the Withuhn conjugated drive. It has a great deal of theoretical merit, but once it is actually buiilt with suspension (as any practical locomotive would be) there may not be enough advantage to justify the considerable added complexity (and the difficulty of providing axle bearings on the mains, which have to provide the double cranked axles for the conjugating rods). There are also the problems associated traditionally with rear-mounted forward-facing cylinders -- many of which can be solved, but some of which have endemic problems.
On the other hand, by the time of the late '40s the available power from even a two-cylinder engine was producing substantial stress in main pins at any sort of true high speed. That was, and is, a major reason to favor a divided-drive arrangement. I happen to believe that a nonsynchronous method of conjugation is preferable (and have described it to a certain MEGO level) but it is beginning to appear as if conventional methods can provide most of the benefits of duplex conjugation without the, er, actual conjugation. Traction control via the independent-brake mechanisms is one approach with promise.
It is entirely possible that a 'duplex' for general service might require only two-wheel lead and trailing trucks. I do think that larger grate area is preferable even when competent Rankine-cycle optimization has been done elsewhere (a la Chapelon, Porta et al.) and therefore a four-axle trailer (principally for weight-carrying) would continue to be used. We've been over much of this ground in Juniatha's past threads on modern steam evolution.
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!
www.leviathan63.com
tomikawaTT 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.
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.
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 all sizes and shapes and pressures and ratings for various applications aren't going away anytime soon.
So what are the combustion systems. Lately, natural gas seems to be the answer. The "U" converted the Charter Street central plant to gas, which raises steam to heat the buildings in summer and provide chilled water for A/C in summer -- I guess they use steam-ejector chillers? The MGE Blount Street electric plant also is scheduled to fire its boilers on natural gas -- I am told they are shuttering their 900 PSI boiler and keeping only their more efficient 1200 PSI boiler after the conversion.
As I have been reading up on steam locomotives and steam power, the two main coal combustion boilers in town are no more, especially since I am learning from Wardale and other readings what questions to ask about how these boilers operate but coal combustion and maybe even the people to answer those questions are being retired.
OK, I get the sense that "the big boys" use pulverized coal combustion. The coal is ground up to the fine consistency of face makeup and then blown into the firebox with compressed air, where it burns like a gas flame -- there is little smoke, no cinders or "carbon carryover" to lower efficiency. But much if not all of the coal ash with its lung-harming micro silicate particles and fish poisoning mercury goes up the stack, that is, unless they use some kind of stack gas aftertreatment.
The "not quite as big boys" (the Charter Street plant -- never did get to find out) use a variety of methods, including Fluidized Bed Combustion. I don't get the sense that Fluidized Bed Combustion is any time ready for steam locomotives as it takes a day-long startup procedure to get stabilized.
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?
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
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 can melt depending on the type of rock formation). That melted ash can resolidify, creating these glassy rocks called "clinker." If too much clinker forms, the combustion air is choked off, the fire dies down, the boiler pressure goes down, and the locomotive slows down and come to a stop. On the "high iron" main line. With following trains. The clinker can be broken into pieces that will fall into the ashpan with a long poker thrust through the open firedoor, but that is hard work. Locomotive crews and especially firemen just hate clinker.
And then there are the cinders and the "carbon carryover." According to Wardale, the smoke you see from a steam engine is regarded as pollution, but it is really a minor waste of coal, mainly soot formed from incomplete combustion of the liquid part of the coal, the coal tar. The big waste of coal is the carryover in the form of cinders. Especially at high steaming rates at full power, the combustion draft lifts the burning coal particles when they burn down to a certain size, and those flaming "sparks" or "cinders" are swept through the tubes, where they wear things out, and out the stack, where they annoy people. Like the people at trackside whose property is set on fire. Or persons wearing white shirts or hanging laundry to dry near the tracks. Or the accountants who see the coal expense. A stoker is said to make this worse as the work conveyor can grind up the coal into small particles, and these particles are sprinkled on top of the firebed, where they can be swept out the chimney before they have a chance to burn.
So before you even see the relative cost of burning a lot of coal vs a small amount of expensive oil fuel, or whether the track pounding from the drive rods is worse than the pounding of axle-connected traction motors, you see why railroad management and the crews working for them like Diesels.
zkr123 If someone was to create a steam locomotive with today's technology, what would it look like?
It would look like this:http://www.5at.co.uk/
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Paul of Covington 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?
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?
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 every which way!
Wardale talks up the Garratt as the "answer" to meeting the Diesel challenge by 1) having more powered axles like a Diesel, and 2) having a completely unobstructed ashpan to address some of the concerns I expressed in a prior post. But then he looked at a South African Railroad Garratt, the GMA/M class imported from England, I believe, and he explained that the coal and water consumption were really high, and the pressure drop from superheater header to cylinders and then exhaust backpressure from cylinder exhaust back to the blast pipe were really high. I am wondering whether steam power can tolerate really long steam pipe runs and be efficient.
My high-speed reciprocating jack-shaft drive steam engine concept, where a high speed piston engine turns a jackshaft (a crank, really) that is coupled with straight rods to the drivers is 1) meant to get the low dynamic augment of the S-2 and other rod-drive turbines by eliminating the angling rod off the crosshead, and 2) keeps the steam and exhaust passages short.
My divided-drive version of this has two sets of high-speed piston engines, back to back, one driving a set of drivers under the boiler, the second driving a forward set of drivers under a water tank as in a Garratt. Per Wardale's Garratt proposals, that water tank would be an emergency water reserve kept filled to maintain traction, and water would be drawn down from a trailing tank car as done with the GMA/M. This leaves the ashpan unobstructed by a trailing truck, and the coal tender would be supported by carrying axles and be articulated with the locomotive to stabilize the tracking. Both sets of steam engines would have short steam and exhaust pipes.
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 burning in contact with the secondary air, introduced above the firebed where it cannot do the mischief of lifting the burning coal particles off the firebed and out the stack.
The (Red Devil) is in the details. Porta developed the idea and got it to work with these narrow gauge steam engines operating in far southern (i.e. cold part of) Argentina. Wardale took those ideas and tried to get them to work on two steam engines in South Africa, one of them being the famous Red Devil, and tried to get it to work on a QJ locomotive in China with what charitably be called "mixed success."
Wardale reported that the Gas Producer System was technologicaly beautiful -- when you could get it to work. His take was that it was much more efficient with greatly (reduced) carryover when he got it to work, but getting it to work depended greatly on just what coal you were burning as well as educating the crews on the correct procedures, that included such things counter to their training of piling on a thick firebed and leaving the firedoors at least partly open at all times to get enough secondary combustion air into the firebox. It also took longer to build up a firebed and get it into stable Gas Producer operation -- you writes of one fireman who just piled on a bunch of coal, resulting in a big blast when it generated enough gas to flash-over -- on one was hurt, but it gave a scare.
In China, the coal was so bad -- "rice coal" -- mainly small friable particles, that he couldn't get good gas producer firebeds, even in static tests of locomotives with the drive rods removed. He thought that the reason the Chinese were even able to burn this coal at all is that had something akin to a "slag tap" combustion system going -- they had enough molten clinker on the firebed that when they stoked this coal, it would stick to that slag and not get carried off. Maybe Wardale, with more resources, have tried to understand what the Chinese were doing and try to improve that.
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...
www.trainweb.org/tusp/ult.html
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.
Paul Milenkovic Should I start a new thread on "combustion processes" or would that result in the TLDR and MEGO effects?
Not to ME!!! ;-}
OK, I get the sense that "the big boys" use pulverized coal combustion. The coal is ground up to the fine consistency of face makeup and then blown into the firebox with compressed air, where it burns like a gas flame -- there is little smoke, no cinders or "carbon carryover" to lower efficiency.
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:
... [The] hydrogen and carbon monoxide then ignites when "secondary" combustion air is introduced above the grate.
Well, not exactly, and therein lies the 'rub' of the gas-producing system. (It is beneficial to study what the reaction conditions through the flame plume in a conventional locomotive boiler are when looking at various firing 'improvements', btw)
First, the 'ignition' presumes that the transition temperature is high enough, and the energy uptake high enough to make transition, to achieve combustion. Second, the ignition presumes adequate mixing of the secondary air with the gas plume to achieve full 'stoichiometric' equivalent... ideally without introducing too much excess air. Third, we still need to account for the behavior of the atmospheric nitrogen; in particular, we can't heat it excessively or it will give us NOx pollution even at fractional-atmospheric ambient pressure.
I also have a grim suspicion that Porta's 'cyclonic' combustion chamber arrangement actually has flow patterns different from those he expects, especially at high turndown and during flow-transition between low and high turndown.
I don't get the sense that Fluidized Bed Combustion is any time ready for steam locomotives as it takes a day-long startup procedure to get stabilized.
Per Blue Streaks comment:
A cab-forward wouldn't necessarily have to be an oil burner. The Germans built some cab-forward coal burners in the years prior to World War Two. However, the engineer and fireman were separated, the firebox being in the back of the boiler by the tender. How'd that work out as far as co-ordination of effort was concerned? I don't know. Possibly not too well, German steam that survived into the sixties seemed to be of conventional layout.
Firelock76The Germans built some cab-forward coal burners in the years prior to World War Two. However, the engineer and fireman were separated, the firebox being in the back of the boiler by the tender.
The information I have (for example Gottwaldt, Streamlined locomotives of the Reichsbahn, p.33, showing the 'Kohlenstaub-Sonderbauart' [the specific/special design for pulverized coal] on 05 003) shows the boiler 'back-to-front' with the firebox adjacent to the cab (and both crewmen together) just as expected. The little door at the 'rear' of the shroud is access to the air compressors, smokebox door, etc., not access fo a 'power compartment' as on N&W TE-1 or Bulleid's Leader.
Juniatha will have full mechanical details of how the burner and windbox were arranged; from what I can tell, the feed was from the throat of the firebox (as with some oil-burning practice) but the 'burner' is shown extending the length of the firebox sides. I'd suspect that some version of forced draft via the 'Luftkanal' was supplied, in addition to the more normal induced draft via the stack and whatever overpressure came in by way of the entrained hot air in the fuel mixture.
If I understand the setup correctly, the coal supply runs pressurized. A turbine air compressor and air preheater supply hot compressed air to a stoker-like feedscrew, with the coal dust then becoming entrained in the air stream in a mixing chamber -- this was then blown to the burner, the mixture comprising much of the primary air and the fuel together... this would not bode well for leaks, although I'd expect the thermal mass of the arch would keep things lit short of a need for explosion doors. At least I'd hope so.
My suspicion is that if all else worked as expected, the violently explosive nature of pre-ground coal dust, and its propensity to stick or 'bridge' with even small levels of humidity, would be reasons against use of the idea. Note for instance that there is essentially no way to access the worm with coal dust in the bunker while the locomotive is on the road.
blue streak 1 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.
Why would you need a stoker that goes all the way to the cab?
With modern automated equipment the fireman can monitor the firebox and operate the stoker remotely from the front of the locomotive.
That was how the American Coal Enterprise ACE-3000 (and related proposals) was designed to operate;
https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US4425763.pdf
The German innovation's description causes me to ponder:
Did they reinvent the Camelback, the Mother Hubbard, countless Anthracite burners?....rarely called saddlebacks....that isolated the fireman at the rear and could have been designed to put the cab further forward.
Thanks for the comments that included the ACE3000 pics.
I think the article included another, different, interpretation of the ACE in concept art.
Modeling the "Fargo Area Rapid Transit" in O scale 3 rail.
BoydI haven't had a chance to read all replies,, could it be fired with natural gas or ethanol?
It could, but it probably shouldn't be. Ethanol is excessively expensive and has some chemical drawbacks as an external-combustion fuel (some of these are the same characteristics that make it a good racing fuel). It's also relatively lacking in heat content compared to liquids of equivalent volume that have more carbon.
Natural gas has a very low heat content both by mass and by volume. You can go with CNG, in which case you have pressure issues, or you can go with LNG, in which case you have refrigeration and condensate issues. The situation is not at all like diesel fuel, where you can essentially slop the stuff around in buckets and not worry excessively about flashpoints, critical-mixture explosions in ambient air, and other more or less nasty things natural gas firing not done via fully sealed pipework can provide for you.
Where ethanol -- and methanol, which is easily made from methane -- shine, in potential, is in direct-steam cycles, for example the approach taken by Oxford Catalytics to generate reasonably-superheated steam directlly from catalyzed reaction of fuel with about 30% hydrogen peroxide. I don't expect to see direct steam cycles deployed on locomotives any time soon!
RME
carnej1 With modern automated equipment the fireman can monitor the firebox and operate the stoker remotely from the front of the locomotive. That was how the American Coal Enterprise ACE-3000 (and related proposals) was designed to operate; https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US4425763.pdf You are underestimating the work of a fireman at the backhead. Watching water level., making sure coal was on all parts of the grate, eliminating clinkers, and many other items others can name
You are underestimating the work of a fireman at the backhead.
Watching water level., making sure coal was on all parts of the grate, eliminating clinkers, and many other items others can name
Overmod Firelock76The Germans built some cab-forward coal burners in the years prior to World War Two. However, the engineer and fireman were separated, the firebox being in the back of the boiler by the tender. The information I have (for example Gottwaldt, Streamlined locomotives of the Reichsbahn, p.33, showing the 'Kohlenstaub-Sonderbauart' [the specific/special design for pulverized coal] on 05 003) shows the boiler 'back-to-front' with the firebox adjacent to the cab (and both crewmen together) just as expected. The little door at the 'rear' of the shroud is access to the air compressors, smokebox door, etc., not access fo a 'power compartment' as on N&W TE-1 or Bulleid's Leader. Juniatha will have full mechanical details of how the burner and windbox were arranged; from what I can tell, the feed was from the throat of the firebox (as with some oil-burning practice) but the 'burner' is shown extending the length of the firebox sides. I'd suspect that some version of forced draft via the 'Luftkanal' was supplied, in addition to the more normal induced draft via the stack and whatever overpressure came in by way of the entrained hot air in the fuel mixture. If I understand the setup correctly, the coal supply runs pressurized. A turbine air compressor and air preheater supply hot compressed air to a stoker-like feedscrew, with the coal dust then becoming entrained in the air stream in a mixing chamber -- this was then blown to the burner, the mixture comprising much of the primary air and the fuel together... this would not bode well for leaks, although I'd expect the thermal mass of the arch would keep things lit short of a need for explosion doors. At least I'd hope so. My suspicion is that if all else worked as expected, the violently explosive nature of pre-ground coal dust, and its propensity to stick or 'bridge' with even small levels of humidity, would be reasons against use of the idea. Note for instance that there is essentially no way to access the worm with coal dust in the bunker while the locomotive is on the road.
I think Firelock was referring to these two much earlier locomotives:
http://www.aqpl43.dsl.pipex.com/MUSEUM/LOCOLOCO/KPEV/prussian.htm
The 4-4-4 was rebuilt without the forward cab. I don't know whether the tank locomotive was similarly rationalised.
M636C
blue streak 1 carnej1 With modern automated equipment the fireman can monitor the firebox and operate the stoker remotely from the front of the locomotive. That was how the American Coal Enterprise ACE-3000 (and related proposals) was designed to operate; https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US4425763.pdf You are underestimating the work of a fireman at the backhead. Watching water level., making sure coal was on all parts of the grate, eliminating clinkers, and many other items others can name
The ACE3000 designers included many of the major proponents of modern steam including Livio Porta and David Wardale.
They designed the locomotive to use modern automated coal handling and combustion chamber/boiler systems based on then current practice in the power generation industry.
If you read the patent I cited in my earlier post it explains why the firebox setup would not require the fireman to handle the same tasks as on earlier coal fired steamers.
Note I am not saying that the ACE3000 would have been able to successfully complete with diesels but I do think it would have been able to operate as designed.
Overmod BoydI haven't had a chance to read all replies,, could it be fired with natural gas or ethanol? It could, but it probably shouldn't be. Ethanol is excessively expensive and has some chemical drawbacks as an external-combustion fuel (some of these are the same characteristics that make it a good racing fuel). It's also relatively lacking in heat content compared to liquids of equivalent volume that have more carbon. Natural gas has a very low heat content both by mass and by volume. You can go with CNG, in which case you have pressure issues, or you can go with LNG, in which case you have refrigeration and condensate issues. The situation is not at all like diesel fuel, where you can essentially slop the stuff around in buckets and not worry excessively about flashpoints, critical-mixture explosions in ambient air, and other more or less nasty things natural gas firing not done via fully sealed pipework can provide for you. Where ethanol -- and methanol, which is easily made from methane -- shine, in potential, is in direct-steam cycles, for example the approach taken by Oxford Catalytics to generate reasonably-superheated steam directlly from catalyzed reaction of fuel with about 30% hydrogen peroxide. I don't expect to see direct steam cycles deployed on locomotives any time soon! RME
The railroad industry doesn't seem to agree with you about LNG/CNG fuel as they are pressing ahead to develop the technology given Natural Gas's current price advantages vs. diesel.
Whether the effort goes any farther than Burlington Northern and UP's similar experiments back in the early-to-mid 1990's remains to be seen.
The main reason not to use the fuels mentioned in a steam engine is that internal combustion engines burn them much more efficiently.
The Oxford Catalytics concept is intriguing, do you have a link?
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