PRR8259I never heard of the Ringelmann chart
The ringelmann chart is just a gray scale. It was actually used to certify on-highway heavy duty diesel engines for emission compliance in 1986.
I had to attend a one-day qualification school to use it properly. I probably still have the certificate for that.
You looked through the hole in the middle at the smoke, and compared it to the gray scale around the center.
It was literally a Fred Flintstone joke. I cannot believe we actually used this.
-Kevin
Living the dream.
PRR8259Sure 18% thermal efficiency would be an improvement over traditional American steam designs, but clearly not enough of a design improvement for the investors.
I confess I was amused at the assertion that a modern diesel prime mover has fewer moving parts than a reciprocating two-cylinder locomotive of equivalent dbhp, but I suppose you can explain that somehow. The more important point I think you should have made is that in a modern engine all the parts require less regular attention than those in 'legacy steam' -- but consider that the same materials and advances often apply to steam components, particularly in the details of 'oilless' engines or the piston side of an asynchronous compound.
Keep in mind that the criteria Porta mentioned do not revolve around pure thermodynamic efficiency, and in many cases shouldn't. The one that should most matter is net dollars per ton-mile, and the considerations of service infrastructure become much more important now that things are 'reversed' and the entire structure of efficient steam maintenance is lost, while sometimes very expensive diesel-centric modifications to plant have been made. Much of this is relevant to prospective operation of the T1 Trust's locomotive, certainly where running support out on the road is expected.
For fun with economy, although not much fun to model (the FG-9 would be more interesting if you have a big enough subwoofer) consider the original enginion AG cycle -- break out your old Penn State thermo textbook, or I'll send you mine from Princeton if you want a schools contest -- which used ultrasupercritical steam at about 7500psi and a separately-fired superheater at about 950 degrees of superheat. This was metered through what was essentially a modified fuel injector into uniflow cylinders, using pilot injection (I believe they used only full excursion with the equivalent of PWM for net mass flow) at very low mass flow -- this was highly distilled water, of course, and the presumption was that the actual 'steam rate' mass flow was low enough that expedient condensing could be assured through proper exchangers. My opinion was and is that some version of Holcroft-Anderson 'recompression' could be made to work on the low side to ameliorate the exhaust expansion issues if necessary, since (as with diesels) a significant amount of developed shp from expansion is needed to run the BFP train and it is more than usually critical (couldn't resist the pun) to obtain steady liquid-phase return to it in the absence of large amounts of tempered first-stage feedwater.
I might also mention that the Oxford cycle of catalyzed steam generation is 'steam' by the current definition, as it uses a fuel to provide the heat and generates from 8 to 11 molecules of steam at appropriate 'power' superheat for every carbon in the fuel chosen. The drawback here is not thermodynamic or capital related; it is political: the cycle involves high-concentration hydrogen peroxide which when combined with the easily-available solvent acetone produces a rather good state explosive.
wjstixThe ACE 3000 project had the idea of building a steam engine that looked more like a two-unit diesel, and burned a slurry of coal and water.
Interestingly this is right at the point Foster-Wheeler was patenting their fluidized-bed locomotive boiler -- something Mr. Mock might find interesting, especially in light of what would have to be done to it to make it practical in a contemporary railroad context. The fuel choices there (and the options would currently involve an interesting array of clean-coal alternatives) did not require slurrying the fuel either for transport or introduction. Getting proper luminous flame out of the thing was something of a different story...
There were a huncha buncha other reasons the ACE3000 would have failed, so the point stands, uncorrectable by me. The ACE5000 as 'shaping up' at cancellation time might not have been quite as lame, but wasn't anybody's answer either.
Overmod--
Thank you for that information. I'm a civil engineer--because we don't have to worry about things that move other than vehicle loadings on bridges--so our required knowledge of mathematics is much simpler and we don't have to know rotational dynamics very well (which is used as a weedout course anyway). I must confess to barely passing thermodynamics, as it was required to graduate, and most civils didn't do so well there. So I'm sorta following you, but not totally.
I was trying to keep things pretty general: steam power was extremely maintenance intensive, with easily more than 100 spots on a big articulated that needed lubrication before each and every run (even considering mechanical lubricators were in use). It was said that roads like Norfolk and Western and Nickel Plate Road had "dieselized" without yet having actually dieselized because they developed state of the art steam servicing facilities that in BOTH cases (and I think UP also) could have an engine coaled, watered, fully checked out and lubricated and ready to go in less than 2 hours. All of that is amazing when you consider the work involved to get them ready to go in any weather at any time of day.
I do think the advanced steam power might, might, have had a chance if not for all the coal/oil/water/ash/below engine inspection facilities having been completely demolished, and the tremendous cost that would be required to begin to put a system like what the railroads had back into place. Remember, it had been more than 100 years over which those facilities had accumulated to the level that existed in 1950. It would be most impractical, and extremely expensive, to begin to rebuild that infrastructure today or at any time since.
Track alignments that were altered as those facilities were removed would have to be re-aligned yet again...
Had the railroads thought ahead, instead of how to take advantage of the almighty scrap dollar, and "banked" some of the steam servicing facilities for the future (just in case), like they've done with the rail trails that have actually preserved graded alignments for some future day that may never come, then implementing a modern steam program based upon economical use of the fuels might have had a chance.
Unfortunately, having banished steam locomotion as "outdated" few were willing to entertain the thought of bringing it back, and it remains for a few design experts, or crackpots, depending upon one's point of view, to consider what might have been.
Not being a mechanical engineer, it does appear that diesel locomotives in today's readily available horsepower "building blocks" of around 2000 to 4400 horsepower are more cost effective (and relatively easily maintained) than 8000 horsepower steamers when you wouldn't need 8000 horsepower very often.
So it remains for more academic types to conjecture about what could have been.
John
PRR8259I do think the advanced steam power might, might, have had a chance if not for all the coal/oil/water/ash/below engine inspection facilities having been completely demolished, and the tremendous cost that would be required to begin to put a system like what the railroads had back into place. Remember, it had been more than 100 years over which those facilities had accumulated to the level that existed in 1950. It would be most impractical, and extremely expensive, to begin to rebuild that infrastructure today or at any time since.
Most of the solutions for 'modern' steam -- and this goes further back than the stuff I did -- don't involve the large fixed infrastructure that was more 'appropriate' in the days when large numbers of dedicated people could use cheaply built but complicated large plant. Note that the functions of lubritoria are easily achieved with little more than a set of appropriate guns, hoses, and tanks hooked up to a source of 140psi -- hint, hint -- compressed air. This can be mounted on a sled, trailer, swap-body or truck. The advent of M-942 grease lubrication of roller bearings and appropriate long-term seals, which of course is mainstream for car maintenance now, made much of the 'care and feeding' of large specialized roller bearings much easier and more direct, and in my opinion will solve most of the fretting issues that might be associated with oil lubrication when a locomotive is stored for a period of time 'loaded' on its own wheels. An interesting range of hard and thermal-barrier coatings and methods to apply, maintain, and inspect them are available to reduce service issues for things like rings and glands. I am currently working on seeing how cerium steels adapt to high-rate repetitive flexing (as found in Timken thin-section rods).
The key insight Tom Blasingame had was similar to what's made hydrogen 'practical' as a transit-vehicle fuel: outsource the support functions. A locomotive designed after 1970 will not have an 'ashpan' out of which crap blows in the Nebraska gales; it will have a system analogous to that installed on SS Badger that conveys the ash into relatively well-sealed containers, from which it is securely transferred (e.g. with the aid of augers or vibrators, or via modular 'ash-packs' on the principle of the ACE3000 coal-packs) and contracting to have this service done whether 'on excursions' or in some appropriate service is the way any sane railroad (to say nothing of PSR-crazed ones!) would adopt. In all probability this would be part of the 'contract' for fuel provision, ranking, blending, treatment (and there is considerable treatment for modern locomotive fuel, including SRC!) -- think of it as a Hulcher for providing, loading, and servicing the 'fuel and its leftovers'.
Now of course you have already recognized one of the great problems with most of the 'modern steam' that is solid-fueled: not all the ash stays in the pan, and there are hard limits to what gets ejected 'elsewhere'. Likewise no modern engine is going to use effective water treatment and traditional continuous blowdown at the same time -- UP gets away with it because they own the railroad and don't mind the problem, but it's not the 'right' environmentally-responsible answer. Stuff to deal with this ... and servicing that stuff ... represents an additional level of fun that is best outsourced, even if to a subsidiary.
Even in comparatively large-scale applications of 'modern steam' the fuel stations would likely be either portable or at most semipermanent. I'd expect them to be co-located with diesel refueling points where possible although my preference has always been at an appropriate point on a siding of some kind. The far more important consideration is water. All these modern locomotives require good-quality treated feedwater, which is NOT something dispensed via track pans. And it was clear by no later than 1944 that any power of greater than about 7000hp in a single unit would have a colossal water rate, so much that even with auxiliary tanks the range might be little more than 150 miles between fillings. Likewise the condensation requirements for that horsepower, even if liquid-to-air exchange, are heroic in surface area and extremely unhappy if choked even slightly.
This is where the Holcroft-Anderson recompression scheme comes in: it 'saves' the latent heat of vaporization -- which is considerable! -- by using a separate engine to recompress the exhaust steam into a 'leaky condenser' arrangement that uses feedwater to cool the steam just to the point it will not flash when pumped back to the boiler at design back pressure. (This was actually tested in Britain and, in the right operating regimen, was an operating success -- they had problems with the draft arrangement, which used a dotty steam motor to drive the wrong fan mounted in the wrong place, which caused the experiment to fail, and the whole company that designed the recompression was destroyed in the blitz during WWII.
There is an additional possibility, which is to augment air-cooled condensing with water spray. Here you would not use feedwater, but rather 'greywater' in separate tankage misted onto appropriate sections of the condenser train. That water could happily be supplied through modern approaches to track pans (that can work on grades and curves)...
I'd like to be able to agree fully with this, just as I'd love to find a 'future' for a Sam Rea line in modern railroading. Both of those were optimized for something that doesn't exist any more -- the old facilities around the wrong kinds of fuel provision with the wrong numbers of people (doing very wrong jobs from a modern economic point of view). Whether they could be cost-effectively converted to do what a modern supply 'infrastructure' would do is a story that would be interesting to address -- and I suspect you are very qualified to do that.
... it remains for a few design experts, or crackpots, depending upon one's point of view, to consider what might have been.
Mind you, there are things that would have been really fun, including adapting Roosen's rather than Besler's motor locomotive to run with a more efficient firing system, say the B&W chain-grate watertube setup designed for Jawn Henry. Perhaps the best of all, if self-admittedly a bit crackpotted, is the use of combined-cycle bottoming with supplemental firing (or Oxford cycle steam generation) on an ALPS locomotive, which is basically applying the same technology to steam power that the French did for nuclear-powered trains... I'll admit that it's not quite as grand to make only part of the horsepower from steam, but a number of cognate developments in Europe have demonstrated both the workability and the potential economic and welfare benefits...
it does appear that diesel locomotives in today's readily available horsepower "building blocks" of around 2000 to 4400 horsepower are more cost effective (and relatively easily maintained) than 8000 horsepower steamers when you wouldn't need 8000 horsepower very often.
And thereupon hangs more of a tale. Note that the 'target' for a STE design envelope 'has to be' two 4400hp locomotives 'cabs-out', and in many respects that's a modular 'sweet spot' for a large number of contemporary train operations. As we get further into the current wacky PSR-driven operation of enormous consists, the use of 'dedicated' "8800hp" locomotives both as lead and DP becomes more workable. And this would be nifty except for the sustained market failure of ~6000hp locomotives nearly everywhere in North America.
In part this was attributed to cavitation and other failures in the prime movers that both EMD and GE produced as the 'next step up' from the 4400hp range, but you'll notice that no other Class I bought the 5800hp SD80MACs at any point, and those companies that had running 6000hp locomotives quietly derated them or re-engined them "back" to the general 4200-4500hp range. This despite 6000hp being purchased and used many other places in the world...
So I think the more 'practical' development of higher-specific-horsepower STEs, comparable to the Russian large gas-turbine development (or the recent Chinese six-unit electric) would be stillborn if you tried to sell it, no matter how convincingly you 'ginned up potential operating routes and services for it.
I promise not to start the rant about current possibilities for the ex-FM OP engine, another thing of immense potential that would not be happily adopted here...
Railking42Nobody ever said it had to run on coal, it can run on Torrified Biomass as well. It has the same energy, density, and material handling properties as coal, without the pollutants.
There was an interesting, if strange at times, proposal from SRI/CSR to use the last surviving big ATSF Hudson (3463) as a kind of science project to burn torrefied fuel ... and set a speed record above 130mph. This led to some decidedly interesting preservation concerns and legal action, and (unfortunately to me as a steam technologist!) will likely not come to pass. But most of what would be necessary to fire an engine that size, at the necessary mass flow, was worked out. And yes, firing with that fuel would have been practical ... now, guiding and stability of that engine at that speed, and some of the other details (like the steam tracting, which was almost preternaturally wretched on the 3460 class), are quite different concerns...
This leads me to wonder if I should start up where I stopped building a model of the 'modifications' ... hmmmm. There's the thing our OP ought to think about doing with his overprint. The arrangements to fire with torrefied fuel, and do functional streamlining with induced slipstream drafting and Franco-Crosti economization, and the cylinders, tracting, rods and other gear appropriate for higher rotational speed...
I can line him up with a source to study Glaze's balancing book, if he wants an accurate thing to model to reach high rotational speed...