This was a project in Cuba in the late 1990s that ended with the passing of its principal engineer in Cuba.
Other nominations go to Wardale’s Red Devil locomotive in South Africa, the ACE 3000 project that never advanced beyond the Vu-Graph stage in the U.S. and the improved QJ class in China that Wardale had a role in developing.
What is special about the LVM (Locomotora Vapor Moderna) is that instead of “replacing the diesel” in mainline Class-I road service in the U.S. as the ACE3000 intended, this was meant as an industrial switcher/light branch line locomotive. Its much smaller scale and the setting of less ambitious sights made its development more realistic.
What is interesting about the proposal is that it didn’t hold back – 360 PSI boiler pressure with a staybolt firebox, 3 cylinder compound expansion, low-pressure cylinder steam reheat, feedwater heater, smokebox “economizer” (2nd stage feedwater heater), combustion air preheater and a cyclonic firebox to minimize particulate emission.
The 3-cylinder arrangement required a cranked axle, but may there is lower risk of this thing breaking in this lighter duty application? ALCo build 3-cylinder simple expansion locomotives culminating in the 4-12-2 Union Pacific type, but Alfred Bruce writes that this was always regarded as a maintenance and a catastrophic failure concern?
As to trying every advanced steam idea Porta could think of, maybe the better to do this on a small locomotive than something road-enginer scale?
Switch engines are notorious for burning through a lot of coal on standby, but Porta thought that with enough cylinder insulation and with damper-controlled air to the firebox, he had this problem licked?
The problem with the LVM-800 only began with its optimization for bagasse being the lettering of ‘BIOMASA’ on a strategically-placed bunker drawing. We had an extensive discussion on more than one occasion on the Yahoo steam_tech list, where a couple of participants had extensive firsthand experience with bagasse firing, and they were not at all sanguine that the trick would work even with top-notch training and oversight. The idea of a cyclonic-firebox installation at high pressure in Cuba, the land of the repeatedly bead-welded throatplates, verges on the terrifying. If I recall correctly, until recently not one ‘correctly-calculated’ Lempor remained in actual service – and a couple of the attempts were true whoppers, discussed only off-the-record in somewhat hushed, if occasionally profane, language.
That there is a role for small steam power, especially in regions where intelligence can be developed but capital is scarce, is undeniable. But that it would be relatively “thermodynamically uncomplicated” also follows in many respects – I would be much more inclined to follow Tuplin on the ‘outline’ of that type of power than LDP (and I don’t say that out of any disrespect).
Minimum practical bound and maximum unit size for ‘mainline’ modern steam converge in a remarkably narrow range: somewhere in the two-high-horsepower units MUed cabs-out range. Smaller and the packaging of the fixed plant and poorer thermo make the thing too much of a compromise even if fuel is cheap and its lifecycle handling cost-effectively outsourced; greater than that and your water rate becomes impossible or your condensation becomes a vast pain.
In the middle of large and small steam power is the demesne of the 5AT, and here an enormous ‘leg up’ is that Wardale has done the complete example set of FDCs for a locomotive of this size and characteristics. It would be relatively simple either to reduce complexity for a sim
A problem, reading between the lines, was that the design depended extensively on both a skilled and motivated cadre of engineering and shop personnel, who did NOT survive political changes. A very similar thing happened with the QJ experiments – apparently complicated by what turned out to be a colossal lack of sincerity about retaining even optimized working steam. This was as I recall around the time the replica Hudson project was gearing up at Datong… only to be dropped with the ‘stated’ reasons being highly suspicious at best.
Thereupon hangs a tale not fully told to this day; Mr. Wardale and Ross Rowland having decidedly different accounts of the project. In my opinion far more detail design needed to be done even on the (grossly overcomplicated) locomotive in the patent description, starting with a frame that would work as intended.
I would have been interested to see what the Foster-Wheeler engineers actually came up with out of their ‘research’ on 614T to work on the ACE 6000 or 8000 or whatever fantasy rating the ten-coupled locomotive was intended to be. Certainly there was discussion about it being ‘fast’ the way the 9F was supposed to be fast… just with an ever-so-much higher center of mass, and not particularly careful consideration of steering the back end of the chassis. If you wanted a practical reciprocating locomotive on that general scale, the ‘right’ answer is very much more like a Y6c with Chapelon’s-style modulated IP injection to balance out the engines at 45-50mph road speed…
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What is interesting about the proposal is that it didn’t hold back – 360 PSI boiler pressure with a staybolt firebox, 3 cylinder compound expansion, low-pressu
Prior to HEP, non-steam passenger locomotives had steam generators. These were saturated-steam monotube flash boilers. They were supplied untreated water, and they relied on a continuous blowdown system.
They could not have been that serious a maintenance headache, otherwise railroads would have kept steam locomotives for passenger trains needing steam heat?
My idea on the use of those things for propulsion was not to try to match the firing rate of a monotube flash boiler to the varying steam demand of a railroad steam locomotive. Rather, it would be to cycle such a steam generator on and off to feed a pressure vessel in the style of a “fireless cooker.” That could eliminated the uncovered crown-sheet BLEV explosion hazard of the staybolt firebox.
Or did diesel locomotive “steam generators” blow up and kill engine crews?
My point about the small size of the LVM-800 is that, yes, it had a lot of the high-tech Porta was “pushing” but without the condensing and with that inside-connected double cranks for syncronizing the two drives. Yes, it had a crank axle, but how hard is that if you have less ambitious ideas of the amount of torque to apply?
The concept behind the 3 cylinders is compound expansion, and the idea there is to obtain high expansion at near maximum torque, and we have debated on whether that was possible with a two-cylinder simple or perhaps even a two-cylinder compound with the type of “IP injection” you have talked about.
Porta long advocated for compound expansion for getting thermal efficiency near maximum torque, something the Wardale didn’t seem to “get” based on Red Devil and the 5AT site essays. I “got” this concept looking over Porta’s claims of thermal efficiency for a planned triple expansion locomotive, yes, claiming he could get 1000 PSI pressure out of a staybolted firebox. His “engine map” showed
There were numerous attempts at ‘steam generator’ arrangements for power, not all of which were strict monotubes (let alone tapered once-through with superheat, as with Doble). They can be nifty; you might get a kick out of the projected steam generator for the Cyclone ‘supercritical pressure engine’ which was, for a few shining minutes anyway, going to be the Lingenfelter Sledgehammer of steam LSR vehicles – but as a cheap method for onboard charging of a typical fireless locomotive they leave some things to be desired.
First, we might as well assume typical SG pressure range: no exotic German high pressures and distilled water; second, the only sensible regimen for much of the “SG’s” feedwater is to *recirculate the water mass in the ‘boiler’ (*at overcritical pressure and corresponding temperature) through what is essentially a steaming coil throttled on and off between appropriate limits – you could harden a Raspberry Pi with an SD card and do the necessary firing optimization, avoiding what is now near- rocket science tinkering with restoring weary and expensive Vapor-Clarkson pumps and blowers and spark and relays and stuff. The catch is that you need sufficient overpressure to sparge adequate steam mass flow through adequate volume to make up both the thermal and work ‘losses’ in the engine and ‘boiler’ even if well-insulated, so you need a somewhat hefty BFP equivalent, whereas the Lamont equivalent would do the makeup circulat
Paul, I had the opportunity of studying some Porta Papers, among them the one he gave at the Paris Millenium meeting. According to a participant of this meeting he gave a paper looking back at Chapelon’s 240.A and .P: he promoted a more fully reconstruction (more like a new built using old parts) as a three-cylinder compound with - naturally the HP inside. Outside LP cylinders were dimensioned so outlandish as to make full ihp (due to boiler limits) at around 10 % c/o (full throttle). That immediately raised the question in me what c/o he would think for 1/2 nominal output or less? I got the answer when reading he even proposed to go ‘shorter than zero’ i e go over neutral point into backwards for forwards running and claimed he had done that with one of his rebuilts and it worked “fantastically” (quote)! Now, what happens if you go ‘over the limes’? Valve travel filling will shorten further and lead will increase! Yet there is a small margin where this could work because the expansion section of work still goes in the forward direction, it only works above a certain speed because it needs to overcome the countering process at the increased lead section. Mechanically this is more like the diesel engine works with a very pointed impulse of thrust - very hard running, thus. Mind that for a small output you submit the engine to full piston thrust and possibly a negative thrust towards the end of piston travel because of extreme expansion going even below atmospheric pressure - and of course due to the excess lead filling. Mechanically this would be abusive for a steam locomotive with her extremely large piston thrust as compared to any other engine, same power output each.
One might ask how this enormous LP piston will be supported by the - rebuilding! - given main pin on the drive axle? To that Porta gave a most remarkable answer, in principle saying that “steel doesn’t age” and there was "no need to keep designed loads below its full tensile s
Note that this is just the opposite of the method used on the T1 to lessen main-rod stroke - a key difference (which was reported in detail when the T1 design was discussed in Atlantic City) was that the roller rods could be easily pressed on and off that design. That could certainly not be said for Porta’s ‘design’ – I think about the best that could be expected would be a segmented bronze inner bushing made comparable to the inner lubricant-holding floating bushing in a UP FEF2 or 3, with an outer bronze or compatible eye pressed over the segments once on the pin, machined with suitable radius to allow lateral on the main as for roller-bearing rods. This would also tolerate the very generous radii between machined pin faces that would be needed for the design to work.
In his defense, it does make sense to decrease the amount of necessary overbalance in a high-speed engine, and if you want (for some reason best known to a philosophical engineer like LDP) to do this with mains inside – and there are good nominal reasons to have the mains inside the rods, as well as at shorter stroke than the coupling rods – that design and perhaps no other would do it. Personally I think the rod force to all the coupled wheels, outboard of not only a necked section but an offset one, would be suicidal in the long run – before we take up the issue of making the
you can’t get around boiler water temperature increasing with increasing steam pressure, there is no way any circulator can help you: it will and has to reach its due temp before it can start boiling. What you probably point to is overheating of fireside surfaces due to bad water circulation and thus steam cushioning on the waterside - sure that would likely cause overheating - similar to that caused by scaling. To me, taking care of proper water circulation is a thing not mentioned because it is sine qua non to design.
“Are you familiar with Porta’s design of a non-sliding pin-jointed crosshead?”
No - I had once come up with my own lever system, mainly for slow power. However, an enclosed system where the slide bar goes around the crosshead instead of the old way with the crosshead surrounding the ruler and a good mechanical grease / solid lubrication or if we speak of up-to-date modern technology - a dry-running combination of materials (which then needs to be protected carefully against intrusion of dust and particles) with a slide bar and crosshead is still the best and potentially lightest solution. Such horrible amounts of wear and play as were tolerated in US steam are of course absolutely unacceptable and I wonder if that didn’t break a piston rod now and then. At least it led to a quick demise of the rear stuffing box.
Asymmetrically turned pin with different strokes coupling / main rods:
I don’t think it is worth dropping any more word about that nonsense and the weird forces it creates in the part, the only proper way to have a main pin is the regular symmetrical form, no doubt about it. Btw piston travel of the T1 was very nearly the same as standard with DR types of engines and they had the regular form of pins, i.e. same stroke for both coupling and main rods - there never was a problem with wheel centers cracking between pin and axle - and those wheels were comparatively very delicate in design. Many even 'survived
I guess I am being “tag-teamed” with criticism of Porta’s ideas as being outlandish.
The man did apprentice under Chapelon? He uprated and upgraded the 2-foot gauge Japanese-built 2-10-2’s for heavy coal haulage in Patagonia, Argentina? He rebuilt a metre-gauge locomotive into his compound-expansion “Argentina”? He applied steam-powered rams for underfeed stoking, a version of the Gas Producer Combustion System (GPSC) and one of his improved exhausts to the Hunslet Austerity-class tank switch engine in England?
So by bringing up the Cuban Prometheus project, I am defending Porta as being all-knowing and all-wise in what further steam locomotive development could have accomplished?
To take the points raised, I am skeptical of Porta’s claim of going to 1000 PSI boiler pressure with a staybolt firebox, or of even going to that steam pressure with a watertube boiler. The American Society of Mechanical Engineer (ASME) got its start in developing codes for boiler safety, and they recently published an account of an accident where contemporaneous with the Gulf War, the engine-room crew of the helicopter assault ship Iwo Jima perished from a steam release from a burst fitting in a 600-PSI steam circuit. The fatal accident was attributed to a contractor during a port call for repairs “in that part of the world” cutting corners in replacing the fitting with a substandard part or with the wrong bolts.
Someone can tell me the pressure level that poses the danger that an invisible high-pressure steam leak can cut a crew member in half. The accident with the Fury locomotive using the high-pressure split-circuit Schmidt system in England along with the Iwo Jima accident suggests that pressures not much above 300 PSI are an accident waiting to happen in a mobile boiler subject to the railroad shock and vibration environment. I am also thinking of the scary but non-fatal incident of a burst circulator tube in &qu
Finally, for Professor Thinks-the-Baker-Gear-is-the-Coolest-Thing to have failed to have thought about what Porta’s non-sliding crosshead could be been, such a thing has not happened.
The ACE 3000 specified “pendulum links” for the piston-valve valve gear, where a pendulum link gives a crude approximation to straight line. A much better approximation is the Watt’s link (sometimes given as Watts link) used for guiding the rear axle up and down for the Police Interceptor version of the Ford Crown Victoria full-sized V-8 engined rear-drive car. It is also used by Talgo in its axle-guiding linkage. Steam engine inventor James Watt thought the approximation good enough to use with a beam-motion stationary steam engine, and people in the “live steam models” community have built them that way.
There is a complicated 7-bar linkage due to Peaucellier giving exact straight-line motion, but there is a simpler exact linkage due to Sarrus that is easy to build. The problem with the Sarrus linkage is that it has links sticking out of the plane, and it might pose clearance problems for use as a replacement for the crosshead guide.
Looking at the Wikipedia article Peaucellier–Lipkin linkage - Wikipedia, Lipkin is now credited? Professor Harvey Lipkin at Georgia tech is someone whose mechanism work I greatly admire, but someone stuck his name on this thing? Sorry, a different Lipkin contemporaneous with Peaucellier.
Wikipedia has good animation of the Sarrus Sarrus linkage - Wikipedia, and you can see where it could have clearance problems on a locomotive. I have built models of this Sarrus out of creased foam-core board.&n
Old streetcars were operated that way to spend minimal time in resistance notches. Gasolene autos would get more of a benefit from full throttle and coasting than a diesel auto due to pumping losses past the throttle. I recall seeing a plot of mpg vs speed for a MBZ 240 compared to a MBZ 240D. The mpg for the 240D peaked at 15 mph with a value maybe twice that of the 240, where both cars were presumably being driven at constant speed.
I was under the impression that steam locomotives were most efficient at substantially less than maximum output, possibly more due to less unburned fuel being sent up the stack and more time for the combustion products to reside in the combustion chamber.
That was my farewell to the 52-80 in Berlin in 1993 - a type of engine that never gave up and was thankful for but a handful of taking care!<<
I feel with you. You had told me about it. I know it was hard, but still I keep telling you: don’t be sad it has ended, be happy you have experienced it!
The 42: Yes, I see, (s)he is much more rare than the 52, but doesn’t look as well balanced with the thick boiler, (s)he looks shorter, too (is not really).
Hha! “bad brother of the 52” [:)]
That was before we got to know each other - I could have told you: you had a 30 - 40 % chance of succeeding, but looking at the severs consequences if you didn’t it was fully right to abandon the project; you would have had a person with some power at the head quarters in Warszawa, but the people at Wolsztyn would have given you a hell of resistance against that loco leaving the depot. Irony: I feel the loco still exists and is externally made up. Could somebody from this forum know of it and tell?
the forum reads 9:44 - here it is 9:52: looks like it gives European time with my postings?
Not at all – although it might seem that way, circumstantially. What we’re objecting to are certain places in his work where his ingenuity and passion led to details that might be difficult, or uneconomical, to implement in practice.
LDP was a friend, admittedly early in my life and late in his, and I do cherish his memory and respect the things he knew and loved about steam power. On the other hand, sometimes he seemed to assume certain things that differed from either my understanding or my opinion, and it is about these that I’m commenting. I don’t mean to imply “I’m right and he was wrong” instead of considering the underlying issues for what they are.
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The man did apprentice under Chapelon? He uprated and upgraded the 2-foot gauge Japanese-built 2-10-2’s for heavy coal haulage in Patagonia, Argentina? He rebuilt a metre-gauge locomotive into his compound-expansion “Argentina”? He applied steam-powered rams for underfeed stoking, a version of the Gas Producer Combustion System (GPSC) and one of his improved exhausts to the Hunslet Austerity-class tank switch engine in England?{/quote]All that is so, and you should not leave out the Lempor as an ongoing example of what he was trying to achieve. None of that implies either that everything he innovated was supportable, or that everything he tried was necessarily a success.
There are those who so believe. I deeply wish that someone would put his proposals for ‘improving’ the Tornado replica in detail, because they’re fascinating. To this day Ross Rowland considers him to have been one of the most, i
Actually DNB (as I use the term) can be a consequence of excessive heat flux even through clean plate to water at saturation pressure; I confess I hadn’t thought of ‘hot short’ issues in inner-wrapper plate even at relatively high nominal saturation temperature, just at the overheat temperatures reached in ‘bad’ circulation.
The ‘enhanced circulation’ as with Lamont boilers is to increase the water flow across the affected regions, to mechanically displace the extended boiling before Eisenhoffer/Leidenfrost effect can develop beyond the ability of saturation pressure to overcome it. The temperature of gas at the waterside does not change dramatically, but the nucleation to steam (or potential for departure from nucleate boiling in regions of highest, possibly transient heat flux) does, and of course the plate heating in those regions would increase (against what is now a reasonably-good insulating steam film, as in superheaters).
In a Lamont waterwall, the feedwater circulation is continuous at about 6x times peak steam demand, and 100% of the fireside waterwall is continuously swept at that speed, with the full steam generation carried mechanically through the space and no separation performed vertically into a ‘steam space’ until centrifugal separation. For Cunningham circulation (which takes downcoming water from the convection section and pipes it under jet-pump pressure to a manifold and nozzles spaced near the bottom of the water legs in a staybolted box) there is no 'special acco
The linkage I saw was something worked out, interestingly enough, by comparison to pin-jointing conventional valve gear linkage with either roller or needle bearings to simplify maintenance and long service life; we had discussions on how this might be used with AAR M-942 grease lubrication for life in excess of that of regularly-dressed driver tires.
The problem was that, in the version I saw, this presumed that the pin joints were adequate to ‘take’ any transverse component of thrust or reaction. I was not, and am not, convinced that this could be made to deflect or buckle sideways under not-uncommon conditions, certainly to the point you’d start to see Vauclain Compound-like distortion and blow at the piston-rod glands.
Something you might do with a Sarrus linkage is use a pantograph arrangement rather than simple hinging: this adds to the number of pin joints but reduces the necessary horizontal excursion. Whether this is in fact ‘better’ than good tribology on a suitably hard-faced multiple-bearing crosshead is… open to argument.
or, no: actually I think we better leave it as it is, for me it would only mean having to make up a text explaining details and I have to find and scan the drawing(s), so it would mean hours of work to put it up (and I don’t have so much spare time today) and then it would only create trouble, me having to explain, defend, explain … and so on, it would only mean hassle and bla-bla.
Naw, ok, let’s leave it as it is - nobody hurt, me not either, everything’s fine and we are all happy. Maybe some other time. Steam is gone anyways.
Just an observation from a diesel enthusiast. After reading these various posts, it appears to me that most of the proposed designs discussed entail an increasing degree of complexity that might improve operating efficiency but would require additional maintenance expense on what was already a maintenance-intensive machine.
Part of Porta’s emphasis, ironically, was on making the machine easier to maintain or better in the service for which it was intended. There are examples in late steam practice – the extended use of direct-steaming enginehouse systems; lubritoria; complicated turbine-driven systems to reduce parasitic losses; hot suits with controlled air to go into fireboxes; and very complicated lubrication systems, at the end verging on pressure lubrication, for example. The idea of the cast engine bed as a specialty is a tremendous expense, likely not possible today; its function, though, in reducing maintenance expenses should be preserved (and that is why modern practice calls for a combination of lost-foam castings and carefully-cut and stamped pressings via an appropriate combination of welding techniques).
There is a somewhat lamentable tendency to overemphasize the importance of efficient Rankine-cycle thermodynamics. Interestingly, it’s the powerplant engineers with their Byzantine penny-pinching heat balance arrangements that were among the first to affirm the importance of high running reliability over parsimonious fuel and water consumption – and putting the complications and higher materials and system costs where it most mattered to the real bottom line: producing ton-miles without surprise.
Of course, optimization “today” involves a completely different set of criteria. Even looking at the 5AT effort vs. the LVM800 series will give you a constellation of different priorities (whether or not you agree that all the steps taken in either are ‘right’ from a North American perspective). A very wide range of careful alternati
Maestro Porta may have been presuming a little too much. Steam-hunter Colin Garrett said the problem with Cuban steam maintanance was it ranged from outstanding to bombs looking for places to explode. He did see (and photographed) the remains of one of the latter, and this wasn’t a crown sheet failure, this was the front course of the boiler disintegrating. The engineer was oiling all around at the time, they only found his legs.