I disagree with this. External combustion of coal isn’t pretty from a chemical byproduct perspective, but the emissions are mostly particulate or attached to the particulates and therefore relatively easy to control. Complete combustion, that is, producing just CO2 and H2O, is theoretically possible and interesting work has been done for small scale installations similar to a railroad application using catalysts effectively.
Internal combustion of hydrocarbons under pressure produces an astonishing variety of byproducts, many highly toxic and even carcinogenic, and many in a strictly gaseous state and extremely difficult to control. More money has been spent with less success attempting to develop a diesel engine which can meet serious emissions standards than for any other power source; which is why emissions controls for diesel engines lag far, far behind any other pollution source in our economy and why implementation of significant emission standards for diesel engines has been continually delayed by regulators – because the solutions are incredibly difficult and expensive.
Had there been a production capacity of steam locomotives in 1980 as emission controls were tightening up, and both types had been required to meet stringent emission controls as the single test of viability, we would have steam engines today, and no diesel-electrics.
That’s beyond my background or experience. The engineering papers I have reviewed refer to the effects of the lower center of gravity creating higher lateral forces on the rail and that this would be particularly troublesome on curves whereas the higher center of gravity of the steam engine had acted to keep the rail in place; the diesel-electric acted to force the rail out.
In that era, there didn’t seem to be a disagreement among engineers that the new diesels would be slightly harder on the track, but it is since that time that people look back and declare that steam engines must have been “harder” on the track.
I believe the external combustion engine could make a comeback although I’m not so sure that steam would be the best option. Burning coal to generate electricity to feed traction motors might be more efficient. In any event a modern version of the steam locomotive that makes optimum use of modern materials and technology would be quite different from those beloved polluting kettles that were finally replaced in the 50s.
If it were going to happen, it probably would have happened back with the ACE 3000 project of the early eighties. At that time the price of coal was very low compared to oil, and desinging and building a super-insulated effiecient steam engine to burn a slurry of coal might have been feasible.
However, that price gap was caused largely by a temporary situation: the Iran-Iraq war, which started with both sides destroying the other’s pipelines and oil shipping ports. This made something like 40% of the world’s oil unavailable so the price of oil skyrocketed and caused massive inflation and a recession c. 1979-80. However within a few years both countries had found alternate ways to ship out oil, and were selling it as quickly and cheaply as possible to get money for weapons, causing prices to fall (and the economy to pick up) c.1984.
…If a “new” steam powered unit would ever become reality I believe the final drive would be traction motors. Too much advantage with them to ignore…including dynamic braking.
You will pardon me for the pun i hope but HOLY SMOKE, i seem to have asked a bit of a touchy ? here, lot of passion in these answers, and all i can say is good to see it! i am glad i could get some debate going, even if the ? had been asked before, and to interject some thoughts here as far as some of the posts go, first off i would love to see the modern version of a big boy or challenger running freights but i doubt that the new era steam locomotive would look much like that, as far as the emmisions go from burning coal, i am far more worried about our economy going south because of rising fuel prices then i am about what the anti capitalist greens think about some black smoke, we have the coal right here, well we have the oil to but thats another story for anothe day, as far as rail maintenance goes i have no clue, and for coal gasification, isn’t that like ethenol as far as taking more energy to produce less energy?, and as far as electrification goes isn’t that going to be more expensive becuase of the soaring price of copper and other metals needed, also i would think the upkeep costs would be huge in comparison! and yes i would think that a coal fired steam plant producing electrical power would work just fine, and again thanks for all the good responces here.
…Your correct, it did spark quite a bit of conversation. I believe that’s good. Think we should get to “talking” about a lot of problems in America and see what we could do to overcome them.
Edit: By “we”, I refer to people involved in said problem{s}.
And also a good timeline to follow the rise and fall of the original ACE 3000 project. When the oil prices fell, so did support for the project.
To add to what others have stated above, a 21st century steam locomotive most likely will not look anything like the ones built in the 1950’s and earlier. The proposed ACE 3000 design would give the most likely look at what you’ll see on the rails if this gets to the prototype stage. A lot of engineering data and research was done with the project, and to develop this 21st century steam locomotive, this would provide the best starting point, since a lot of the ground work is already done.
…Tom, do you remember what the final drive system was on the drawings for the ACE3000 unit…? Was it mechanical or did they propose traction motors…or even turbine with gearing being the final drive…I don’t think it had side rods and cylinders to connect the driving wheels. I just don’t remember what design drive system it had. Perhaps we could pull up some drawings on here of it…
Edit: Just found a drawing of it…and to my surprise it was to be a 4-8-2 wheel arrangement setup…2 high press. and 2 low press. cylinders with inside drive rods. I thought I remembered they had a completely different concept for the final drive mechanism…Humm.
The Ace3000 was driven directly by a reciprocating steam engine with rods coupled to drive wheels just like conventional steam locomotives. There may have been some refinement in the principle, but I don’t recall the details.
…Yes, that’s the same illustration of the proposal I found. No, I don’t think it was articulated. I note in my reading to refresh my thoughts on it…it was designed to have “dynamic braking” using the cylinders with opposing pressures. That’s an improvement on the “old” steam engine designs not having been designed to handle that function.
If the question is really, “Can coal burning locomotives be developed,” the answer is yes. They might be turbines (although the experiments half a century ago were less than satisfactory) or they might be gasifiers generating coal gas to burn in an internal combustion engine. They might even be old-time piston types (possibly utilizing the ideas put forward by Bill Withuhn to drastically reduce dynamic augment.) If, OTOH, the question is, “Would it make economic sense to do so?” including ALL the costs (labor, manufacture of new parts, infrastructure…) the answer is - not very likely.
IMHO, the most probable use of coal for railroad propulsion lies in the realm of using it as a base stock for liquid fuel production - with electrification fed from fixed coal-burning steam plants as a distant second.
I used to take the time and trouble to cite these things on this forum, and learned that “studies” generally don’t matter to most people, especially the ones whose minds are made up. Having learned that extending that courtesy to people was pretty much a waste of time, since it was rarely extended back, I no longer take the time to look them up. And the ones who demanded them, were least likely to read them. Sorry.
Here’s the comment I have at my fingertips:
“Small diameter driving wheels, and lower centre of gravity do produce greater track and rail stresses. Rail ‘burns’ from slipping driving wheels are more prevalent with diesel operation than with former steam. It is often claimed that the change from steam to diesel has reduced the cost of track maintenance. Maintenance of way costs have been carefully examined over the period studied to verify this claim. No indication can be found that the change in the type of motive power has produced any savings in this field. Such costs have increased slightly…” H. F. Brown at p. 273-274.
One of the reasons that the Pennsy went with side-rod drives on the DD1 was that a high center of gravity reduced the lateral forces on the rails - the Pennsy set up a special test track to measure track forces. The explanation is to think of an inverted pendulum - a higher center of gravity means less force exerted for a given lateral displacement. These same tests had shown that an asymmetric wheel arrangement produced lower lateral forces than a symmetric wheel arrangement. The Pennsy had to re-learn some of these lessons a quarter century later when evaluating the R-1 vs the GG-1 (both had geared quill drives which should be easier on the track than nose suspended traction motors of equivalent ratings).
Typical steam locomotives didn’t have the torque reserves common to most series wound tracion motors (I’m defining torque reserve as the peak torque minus the torque needed to slip the drivers). In addition, slipping in a steam locomotive is a lot more obvious than slipping on an electric or diesel electric locomotive.
The one area where diesel locomotives reduced the cost of track maintenance was the elimination of dynamic augment of high speed operation. The whole point of the duplex drives was to minimize the dynamic augment.