@ Overmod and Dinodanthetrainman
May I ask you to post your discussion of unconventional designs of steam under this here thread ,
not in ‘What ( conventional !! ) steam we haven’t seen’
Thank you !
Regards
= J =
You might note that the discussions you say are ‘unconventional’ all included contemporary '30s to early '50s designs… I had thought this was the thread that was discussing what the follow-ons to reciprocating steam of the mid-'40s would have been (since you basically covered all the bases of what was “likely” in a strictly conventional line of succession years ago). On the other hand – it IS your thread, and I for one will abide by how you want it to be.
I did direct the ‘trainman’ to the old ‘extreeem steam’ thread, going so far as to ‘bump’ it for that purpose. I apologize if that failed to have the desired effect.
Since all the posts are now gone, I leave it up to dinodan to re-post what he was enthusiastic about here, and I hope he gets some encouragement.
Can I ask this question here? If it is off-topic, I will gladly start another thread.
One of the motivations for “unconventional steam” is thermal efficiency. But just what is/was the thermal efficiency of “conventional steam” in relation to Diesels?
Wardale in “The Red Devil and Other Tales of the Age of Steam” comes up with a magic number of about .033 kg (coal fuel)/metric ton-km (freight ton? trailing ton?). That comes out to about .1 pounds of coal per “short” ton (U.S. ton).
He gives this number as representive of the performance of the 614 pulling trailing “stuff” (including “canteens” or water tenders) in the 1980’s ACE tests – that number went higher when the 614 sprung internal water leaks. He advances this number as being 12 times the BTU usage of the pair of SD-50 Diesels Chessie Systems was using at that time for coal traffic on the same line.
He gives another comparison between steam and Diesel for the SAR (South African Railway) giving a “overall” thermal efficiency of about 3 percent for the 25NC’s, about the best steam engines they had. That figure takes into account the “loafing between loads” and keeping the fire and steam pressure going. The Diesel figure is in the high 20’s. Another place in the book, he quotes .03-something kg coal/metric trailing ton for the “conventional 25NC” and mid .02 kg coal/training ton for The Red Devil, his modified 25NC that was called the sole member of the 26 class.
So his highly modified “First Generation Steam” locomotive was maybe 8 or 9 times more BTU’s than a Diesel?
The infamous H.F. Brown paper puts steam as needing about 6 times the BTUs as Diesels in mainline service. Another observation about Diesels is the advantage is much larger in switch engines than in mainline freights run at nearly constant power.
Here’s my questions. Are
Overmod
non of those rather special things you write about have been part of classic 1940s US Super Power as built by ALCO , Baldwin or Lima . Non has ben put into service on a regular basis by any railroad .
Thus , as for me it is rated ‘unconventional’ - full stop . You are free to open your own thread about all these things .
Thank you for understanding .
Regards
= J =
The post are not gone i backup every page i post on.
What about multiple unit control requiring only 1 crew member to a locomotive and a engineer in either the lead locomotive or a control car no unattended firing.
OVERMOD
"Easily done, and commented on fairly extensively in the various ‘modern steam’ threads here.
As noted, all the necessary equipment to run steam locomotives ‘together’ had been developed by the early 1920s, and the necessary (analog) improvements in things like control amplifiers were developed in conjunction with radio, automatic train control, and long-distance telephony in the decade of the '20s.
Integration with EMD-style MU control to control diesels (from the analog throttle and cutoff controls) is a bit more difficult, because the “throttle” position is essentially digitally determined (4 relays, 4-bit control for the eight notches) and loading rate is only incidentally associated with the governor settings – so you need either a cam or electronic approximation of its functionality to get control without weird short-term latency effects. But in my opinion, nothing that couldn’t be practical in the '30s.
The interesting thing is that it’s not that difficult (albeit with different mechanisms) to control the steam locomotive relative to MU diesel control input. You need an air throttle (like the ThrottleMaster) and precision reverse with a modified Valve Pilot device, with quick and positive transition from one reverse position to another, and reasonably positive ‘locking’ or position-holding.
Once you have the ability to get to an automatic or semi-automatic set of firing controls in case of ‘anomaly’, much of the objection to MU operation of steam goes away. What you are left with then is the necessary union agreements… and it might have been inter
Done.
However, I was just about to post on something that’s a well-known Lima improvement that was never ‘put into service on a regular basis by any railroad’ :
This might be interesting enough to people following the “post-'40s” development thread (now locked) for it to be placed or copied in that thread as a reference. I believe this shows the model that survives in the Museum of Transportation collection…
Credit to Matt Austin, who scanned and posted this on RyPN.
Porta provides this in his ‘definitions’ of the generations of steam power, and the general range of achievable numbers (absent correction for emergent ‘real world’ problems with structure or operational policy) appears to be confirmed by other references. The question fairly quickly devolves somewhat to what your particular definition of ‘conventional’ steam is.
For instance, I consider any testing of a large modern steam locomotive, in heavy service, without an operating feedwater heater to be… well, unproductive of meaningful thermal-efficiency numbers, or engineering development information much beyond what Ross Rowland said about giving the Foster-Wheeler engineers a picture of what was to be encountered in day-to-day line operations.
Systems that were well-established by 1950, notably the Snyder preheaters and Cunningham circulators I keep mentioning, would immediately increase the effective thermodynamic efficiency at least several percent, in more than just steady-state operation. Better lagging, water treatment, and other details would increase it further for little actual trouble or operating cost. On the other hand, much of the pure thermodynamic improvement from many of the more ‘popular’ approaches, classical GPCS being one of the prime examples, requires substantial deviation from typical North American operating conditions and available maintenance procedure.
One problem is that diesel-electrics have not sat at late-'40s efficiency levels… or late-'60s, or early-'90s levels. So in a very real sense the disparity as cited in Brown’s paper is a kind of Moore’s-law phenomenon; you could continue to assume that as a
What about fireless locomotives for switching!
Harry Valentine has done a fairly deep analysis of fireless locomotives in general, and an effective system for switch-engine operations can be developed from that. If you can find any technical information on the Web about the California Solar Steam Train, you might get some useful ‘pointers’ on how the ‘recharging’ process for fireless engines in yard service would be arranged.
You will probably want some high-order heat and ‘regenerative braking’ feeding it, for the required heavy acceleration and deceleration involved in most flat switching. This might also involve one or more ‘hybrid’ style combustion-engine gensets with heat recovery.
A concern is where you place the (usually stationary) recharge locations, and what sort of piping and crew manipulation is involved. Are you charging with overcritical water, or via live steam ‘bubbled’ into the remaining water in the locomotive’s accumulator tank? How high a pressure do you want to work (European fireless locomotives were designed for reservoir pressures in excess of 1200 psi). Check what was done, and see if it matches what would be required for modern American practice… and whatever alternative uses are expected of modern switch engine power, both currently and, eventually, in the used-locomotive market.
oops
The link that i posted here is no longer valid and I accidentally deleted my post on fireless cookers and I think Overmod’s went with it.
Thanks for posting the article about the Lima double Belpaire boiler.
I could see the Thorium based laser heater ( http://www.cnet.com/news/is-a-nuclear-powered-car-in-our-future/ ) much more efficiently used in a steam engine, than a car.
Couple this with condensation recycling of steam/water ( no need for flue steam to help with the draft), and with modern Steam oiling ,roller bearings, and adding dynamic brakes to the trailing truck, you might really have something that would blow the doors off any tier 4 diesels.
What brings people back to Steam?? its sheer power
Water at 211 Degrees f = 80 cal./gram
Steam at 212 Degrees f =240 cal./gram
Steam STILL powers ALL but the solar and hydro plants. That’s 80+% of the power in the US
Not to be a downer, as I agree very emphatically with all the points BARFlyer’s making in his post – but the thorium cycle is NOT particularly well-suited to vehicular use. (Hint to the non-nuclear community: What is it that makes this cycle so ‘non-proliferative’?)
Remember that to work effectively in a practical locomotive, there has to be a source capable of effective superheating on board. This is relatively easy to achieve with one of the thorium cycles – it just involves heating, or heat-transfer cycles, that have the exchanger at appropriate temp for heat exchange to steam… at the required mass flow, to the required degree of superheat. That is very different from putting heat into circulating overcritical water…
Might I suggest a partial return to Holcroft-Anderson ‘recompression’ at this point? It remains just as attractive at conserving the latent heat of condensation as it was in the '20s and '30s…
Don’t just put drag on that truck – or other trucks on the locomotive. Motor them, and equip the steam locomotive so that its motored trucks can be used as a ‘road slug’ when MUed/DPUed to suitable diesel power.
The object is not to ‘blow the doors off diesels’ (fun as that is for those of us who love big steam!) – it’s moving freight as effectively as possible (which includes both efficiency of operation and best practical road reliability). I have no hesitation in using the advantages of diesels in a consist where those advantages
Here are some locomotive consepts.
They are little conservative.
Ant there is this. Thanks to a lot of help from Overmod My bad combination of a lot of good ideas looks plausible.
World’s Worst Combined Cycle steam and Steam Turbine Locomotive
Can any one give me a link to the steam-teck thread?