How efficient is a steam engine?

[CSSHEGEWISCH]

Firelock76

33% is controlling interest if you're the majority stockholder.  Besides, why do you think N&W's passenger coaches were painted Tuscan Red?

33% is NOT a majority.  I believe that the N&W shares owned by PRR were held in trust and PRR was not allowed to exercise control per ICC order.  The prime function of the N&W shares owned by PRR was to pay dividends to PRR, which did much to cover PRR's operating losses.

[BigJim]

Firelock76

33% is controlling interest if you're the majority stockholder.  Besides, why do you think N&W's passenger coaches were painted Tuscan Red?

 

Maybe Ed King should step in and set everyone straight on this issue...which is Pennsy had enough good sense to let the N&W run the N&W!

[BigJim]

Paul of Covington

    Okay, I've overcome my embarrassment enough to thank you all for setting me straight.    All these years I've accepted the story about the enhancements as fact even though I thought it curious that I never found it mentioned anywhere else.     

In the case of the Super A, a westbound train headed by a Class A stalls on the Blue Ridge grade because it is over tonnage. The author deduces that it must have been a Super A or the dispatcher would never have let it try to make the grade on its own. What he didn't know is that many times after trains were pushed east over the Blue Ridge, the pusher waited at the foot of the mountain and pushed another train west over Blue Ridge. Simply an everyday thing that someone blew all out of proportion.

May I add to not believe everything you read in those blurbs under pictures telling you this and that. I have found many a blurb to be nothing more than BS used to fill some space under a photo.

[oltmannd]

Paul Milenkovic

 

oltmannd:

 

 

Some other things I remember.  The condensing tender.  Big condensing radiators with fans power by the low pressure steam (or hot water? I don't really remember)  Exactly how reliable was this going to be?  I remember at the time thinking about how we couldn't keep SD45 radiators from leaking all over the place, and they were only 8 row soldered core running just hot water.  

 

 

 

Yeah, well the temptation is to go with a condensing "tender" because of not needing the watering stops and the more thermodynamically efficient cycle and the need to not worry about hard water.  I have come to accept that a condensing steam cycle without access to a cooling pond, however, is the wrong way to go.  Not that this would have answered your objections, Don, but I believe Livio Dante Porta was trying to pull the ACE 3000 team back from the abyss by trying, as their first effort, to simply build a better non-condensing steam engine as their first effort.

With respect to Diesel reliability, that had to have been developed over time and didn't start out as a given.  I believe the EMD 567 engine was something of a breakthrough as whatever Winton engine they had -- wasn't the story that the pre-war Winton-engine E units had technicians riding in the engine compartments to make repairs underway?  Or is this part of the mythology of railroading?

One other thing about Diesel reliability, I had been reading late-50's vintage railroad trade magazines in the Engineering College library at the U.  I can go look up what the magazine title is, but it had a monthly column on the Mysterious Diesel Problem of the Month.  A steam engine is essentially a big tea kettle -- keep a fire going, keep water in it, keep the bearings oiled, keep the flues unplugged, and the thing pretty much runs.  The Diesel had a complex electrical system -- it was anybody's guess why a Diesel wouldn't run or wouldn't "load up."

If one would indulge me with one last question regarding what could have been done to keep steam going.  The ACE 3000 was probably a Bridge Too Far with its condensing cycle and most certainly a Bridge Too Late what with Diesels being into their second and third generation and having solutions to the aforementioned problems -- the Dash 2 modular electrical cabinet?

The Jawn Henry was also a Bridge Too Far with mating an electric drive to a steam turbine.  But Jawn Henry must have been a non-condensing cycle -- I believe the coal bunker was in the front part of the locomotive portion, but it pulled a water tender?  And Jawn Henry had a non-conventional boiler -- some kind of Babcock and Wilcox 600 PSI water tube affair that was considerably more compact than the massive steam engine boiler?

The Jawn Henry had its turbine knocked out of wack in a hard coupling impact, and it was said to have had trouble with coal dust or leaking water getting into the electrics.  Not much has been said about its boiler.  Was that part of it reasonably successful, to go to a more compact water-tube boiler with higher steam pressure, getting some increase in thermodynamic efficiency (although not the full effect of having a condensor), perhaps mitigating the hazard of boiler explosion by not having that massive amount of water at the boiling temperature.  Could that boiler have been mated to a conventional steam locomotive?  Or was Jawn Henry in service for such a short time and having that many other problems that we never learned if that boiler worked out?

 

Early diesel vs steam from the "transition" guys I started working with:   "Steam:  5 minutes to diagnose.  Two days to fix."  "Diesel: two days to diagnose.  5 min to fix."  

By the time of the Dash two, it was getting closer to "5 min to diagnose, 5 min to fix"

The Dash two locomotive was the culmination of hundreds of improvements.  There were certainly "generations", but there really was a continuous evolution.  Each component was improved bit by bit.  There were at least a half a dozen changes just to the cylinder head just on the 567 engine.  There have been changes to the cylinder liner, the valves, the cylinder hold-down system, the head seat ring, injector nozzles, etc.  The uber-reliable 645-E engine was a long way from the leaky, wheezy 567, 567A and 567B engine that killed steam.  A lot of the parts looked the same, but.....

[BigJim]

I guess this should have been said long before this thread got going sideways,

You should read "The Thermodynamic Closing of the Great Steam/Diesel Debate" by William Pettitjean. That will answer and explain the basic question at hand.

[Juniatha]

Having read the previous comments, I might throw in a few words of mine.

Given historical steam - FGS, first generation steam as it was denominated by Porta in contrast to his proposed second and third generation steam – did typically reach some 8 % thermal indicated efficiency in German standard steam loco classes (simple expansion all), with about 9 % in the best European simple expansion types, 10 % in good compound types, 11 to 12 % in the best French compound types including Chapelon rebuilt 4‑6‑2 and 4‑8‑0 types (pre Chapelon compound around 7 to 8 % in France). 14 % should have been reached in the proposed 6000 i.h.p. Chapelon types of 1950; some 15 % were claimed for L.D. Porta second generation steam with GPCS, 16 % to 20 % should have been reached in the third generation and in best compound designs still using live steam parameters but comparatively  mildly super-elevated over best historical practice. This would then very much approach the end of the line for ‘conventional’ i.e. classic steam of basically Stephensonian concept.

When comparing thermal efficiencies, one has to keep in mind, though, maximum efficiency figures are not what governs daily in-service consumption alone. First, railroad traffic often has engines working off their range of best efficiency with engine working loads varying widely; second, there are idling times which UIC tests on SNCF and DB have shown to bear heavy on diesel engines consumption, actually bringing average efficiency in fuel energy used for a defined scheduled work on a monthly basis down to figures by far less superior to steam’s equivalent figures than those of maximum efficiency for both diesel and steam would suggest! Clearly, the reason for this is in the practical need to keep diesel engines idling through short times of locomotive inactivity, such as train coasting, train stopped in station or at signal, train waiting for departure – but also while a diesel locomotive is on stand-by between two calls of service. Often depots have kept engines idling for hours to avoid having to start the following turns with a cold motor, or where frequent cold / hot / cold circles have led to excessive wear and in some cases even blocks cracking – very much a question of choice between two undesirable extremes: extra maintenance versus extra fuel consumption.

One maybe extreme example from ‘Old Europe’:

In the years following re-unification of Germany in 1990, former (East-German) DR saw many depots sooner or later bound for closure and often large parts of their aged facilities were being torn down at rather rapid pace. In the process of (anticipated, yet never accomplished) ‘privatization’ the two hitherto state-owned railway networks (DB and DR) were ‘combined’ into one DBAG (sort of PC-wise – *g*). In severe winter weather, consequential situations in such depots hung midways between half alive and fully dead has led to dozens of diesel locomotives idling for hours on end in depot yard outsides of empty shed declared out of use by management and destined for demolition (imminent, later, or maybe not). Reason for this sort of ‘simplified running procedure’ was not just fear of letting motors get dead cold but standard practice of no anti-freeze filling – which had worked well enough before with locos parked motor off inside acceptably heated engine sheds.  Besides horrific effects on working morals of railroaders left with imponderable personal perspectives by large-scale thinning out of facilities, this sort of diesel loco handling has sent bluish clouds of fumes all around the neighborhood providing fantastic ‘approval’ by the public of DBAG’s ways of modernization.

This very much brought diesel loco efficiency back down to worst standards of smoky steam depots.

Yet, comparing thermal efficiency of engines proper is but one factor. It has correctly been mentioned before that fuel costs on a BTU / $ basis are what really counts. Because of availability of relatively cheap coal abounding in the steam era in the US, railroads took a dim look at technological refinements to increase thermal efficiency. They preferred to keep design simple. Keeping a machine simple and therefore of low construction cost is one thing - it's a totally different matter if technology is being petrified at rather raw level, even during the steam era becoming more and more out of date as compared to what had become state of the art in engineering outsides the isolated world of steam locomotive construction and maintenance.

In this latter lies the basic reason why 'the steam locomotive' (better: 'this very sort of steam locomotive') has always remained heavy on maintenance and servicing. There is no physical law that determines "engines using steam must inevitably demand higher maintenance and service costs than engines using diesel cycle". Keeping that in mind it becomes pretty clear that most of the extra costs for maintenance and service found in the historical comparison tests of existing types of steam locomotives versus new types of diesel locomotives were really telling of flaws in the out-dated design and construction of steam. Inevitably, running maintenance and servicing of aging steam was costly versus steam by state of the art technology such as present in the diesel locomotives then introduced.

Some extra costs however were inherent with coal as fuel because of disadvantages in handling the fuel and need for fire cleaning plus consumptive effects on boilers by gases and abrasion by cinders. Extra vehicle total working mass of steam locos comes of little surprise with low total thermal efficiency of their dual heat energy conversion process asking for large supplies of fuel plus working media having to be carried on board. Yet, specific power output per mass unit of the best of classic steam was quite competitive to contemporary diesels at the time of transition.

But fuel costs are just one item - maintenance is another. Labor costs also were an important factor and here the classic concept of steam locomotive principally was at disadvantage – although on many European railways laws at the time of transition from steam to diesel out-ruled single handed control at least of express trains, replacing steam firemen by second drivers, or in other words:  nullifying the labor cost advantage of diesels in this respect.

Two more points where diesels were at inherent advantage: vehicles were fully bidirectional and of full adhesion wheel arrangements.  The latter was a feature much welcomed on American railroads forever seeking to take maximum tonnage trains. Bidirectional concept helped to drastically simplify multi unit traction and that again helped to overcome the diesels initial major drawback against Super Power type of steam: low h.p. output per unit, the early types in fact wanting to an almost ridiculous degree for mainline duty if compared unit for unit with the mighty steam loco types then ruling. Because the diesel units – in sharp contrast to steam locos – easily lent themselves for multi unit control from but one cab by just one driver the low h.p. output per unit (not t.e. output) became irrelevant for railroads which quickly adapted to comparing what was called one 'four units diesel locomotive' (i.e. four diesel locos) to one steam locomotive of nominally about the same i.h.p. output at speed – yet of much lower t.e. output at starting. Still, I tend to question if an early type 'four units' diesel of 5400 motor h.p., later 6000 motor h.p., really offered a step forward worth the capital invested and if it had really justified that precipitous conversion from steam when it meant scrapping highly qualified steam loco types at but a fraction of their anticipated working life. Effectively, this has had railroads buying power twice within short time for but one revenue work at hand – a financial disaster not likely warranted by whatever small margins of cost savings to or fro could be claimed according to which way or other the steam / diesel comparisons were interpreted. Had the non written-off costs of just having bought new big steam only to dispense with it after a few years been attributed to the transition to first generation diesel traction – as in my view it should have been done since these costs did not disappear miraculously with the transition – then the balance would have changed substantially.

None of the large state railways in Europe followed these rather hasty changes of traction because of the obvious multiplication of traction costs with multi unit traction by early diesel types lacking power as well as technological 'railroad-hardening' and accurate design that characterized later US diesel types that have well earned their recognition.

On the contrary, on European railways even double traction was always seen as a mere help-out by all means to be avoided for best efficiency of train running. That is why diesels have been compared and put into service on a "one to one" basis: one diesel loco per one steam loco on a train – which profoundly reversed the picture, leaving diesels to loose competition power-wise against steam and leaving diesel traction as perennial second choice against electric traction – so much so that virtually all major lines which in the years of transition from steam had been dieselized have long since become fully electrified – arguably with exception of railways in Britain. Small wonder, with electric loco maximum outputs per unit of engine mass comparing to diesels like three to one, or four to one in more recent years with three-phase synchronous motor electrics! All of the high speed trains wouldn’t be possible if it weren't for the vast power output per mass unit available with electric traction. The like applies to freight train operation where light and simple high power single electric units realize high monthly ton-mile productivity, a major key to high utilization on European double track mainlines with high traffic density demanding fast acceleration and highly uniform traveling speeds of trains.

But in America conditions and demands differ from those found on European railways. By mentioning this practice vastly differing from the developments on US RRs I just wanted to point out: there is no such thing as 'the one best solution’ in applied engineering technology and this applies to choice of traction, too. Given surrounding parameters always have to be taken into account. If that applies to comparisons E traction versus diesel traction, then it should logically also have applied to diesel versus steam – only, at the time decisions were made, the latter case got buried under massive pressing by 'modernization campaigns' that had more to do with hard selling that with hard technical facts if relative characteristics of steam versus diesel were concerned – then, at the years of transition!

By the last decade of steam loco construction in the USA, indicated thermal efficiency should have reached some 10 % in the range of best performance. Should have! Yet it didn’t. With builders answering as they did to customer railroads asking, in my view the railroads should take an ample share of blaming. With cheap coal they just didn’t care for those extra percentage of thermal efficiency – they preferred exchanging old eight wheel tenders against twelve wheel high capacity types and ‘up-grading’ to fourteen wheel centipede and even sixteen wheel types with the large loco types. What went unnoticed was that higher efficiency also meant higher degree of transformation of energy, i.e. higher power output, thus higher revenue per unit of energy invested! In the typical US Super Power 2‑8‑4 or 2‑10‑4 as with the 4‑6‑4 and 4‑8‑4 railroads felt content with approx. 6 to 7 % thermal efficiency around optimum working point – not to mention what was left of it in then all to often found ‘abuse’ type of running with excessive loads at low speeds which had steam locos going at full cry all the way in what might be called ‘starting mode’ i.e. excessively long cut-off working, excessive firing rates near grate limit with inevitable super-increase of coal consumption caused by high degrees of unburnt losses, low combustion efficiency, low boiler efficiency – at the same time producing lower than optimal ton-mile productivity figures because of sheer sluggishness, chocking mainlines with slow moving drag freights and all that just for the benefit of adding some relatively small extra tonnage to a train consist of several thousand tons.

In some articles published in more recent years, authors have blamed US steam loco builders of design and construction of steam loco types that did not fully answer this sort of service. Yet in my view these critics are unfair in that no viable alternatives were offered to the type of Super Power that had then been developed. Little could be offered. The plain and simple truth is: if it was by no means without engineering challenge to design ever increased power outputs at speed into these loco types, it still could be done by following a natural path of perfecting given basic designs. On the other hand it would have been a totally different matter taking a veritable quantum leap to extend steam in such a way as to produce starting efforts equivalent to those of combined t.e. of multi unit diesel combinations. For instance: a then typical 4 x Bo-Bo diesel combination thus having sixteen powered axles would have called for a steam 2‑8‑8‑8‑8‑x type – quite a monster, surpassing in length of powered groups even the early Triplex ventures, something that couldn’t adequately be supplied with steam by the boiler technology then in practice, an excessively long accumulation that would indeed have called for clever arrangements of multi-articulation both for negotiating curves as well as track contortion, humps, low points and any combinations of those. Footnote: probably it could be done using today’s technical knowledge and possibilities of design and construction – yet, if so, it would present an answer to a question nobody wants to ask.

It appears to me, that is why in the ACE-3000 project emphasis was put on “rate of most used continuous tractive effort” – not the maximum one, silently dropping any claim this projected steam type could ever compete with diesels in maximum starting tractive effort. In fact, in its basic performance characteristics it very much started where US steam had died in 1949, adding complications like condensing, internally coupled duplex drive (i.e. duplex no-more, with two crank axles instead of but one in straight eight coupled four cylinder compound types like those used to best advantage in France), further adding automated, electronic controls for mixed operation with diesels – in itself no small task to accomplish considering the new type loco would have been supposed to take care of itself working in a remote controlled multi unit combination, something that has yet to be achieved in  a fully conventional steam locomotive, even if oil fired to simplify remote control.

In his book “The Red Devil and other tales of steam”, David Wardale mentions that L.D. Porta had been with ACE for some time and because of the engineering complexity of the ACE-3000 layout had recommended a more conventional, more basic engineering approach. It was not to be; ACE wanted a steam loco concept that would promise to provide compatibility with prevailing diesel locos – by itself a reasonable approach, it would seem, had it not been for engineering consequences being as severe as they were. Just what was expected to be proven by those ‘heavy tonnage test runs’ of # 614 in most severe winter weather that virtually cancelled much of the data sampling and provided rather extreme off-average conditions of running? I take from it that it could be done – yet the C&O had proven just that back in the times of regular running of these 4‑8‑4s. I also take from it that a 4‑8‑4 is rather on edge when asked this sort of service which diesels perform with little grunting – again, this isn’t really surprising. I apologize if I should have missed the point but it looks to me like an old story retold of a fairly swift engine called to take borderline tonnage, consequently laboring over the line at low speeds far off its optimum working range. On the other hand, Porta’s straight-forward proposal of a Decapod, light yet very powerful would have concentrated efforts on a viable steam loco concept – yet that would have produced an engine not easily adaptable to the railroad scene by then ruling practically throughout in America. Railroads all over the continent were firmly committed to diesel traction and with much improved second and third generation diesel locos, in my view it would have taken a very, very severe increase of diesel fuel costs, indeed sort of a sky-rocketing of oil price, to persuade them to seriously consider anything else. And then again, a locomotive concept of heavy vehicle mass per unit of power output, incorporating many new features or combination of features uncommon to railroad practice would probably still have a hard stand against a proposition of electrification with its loco units of proven, heavy-duty high-end power, of extreme maintenance freeness, all readily available off stock.(Sorry if my appreciation for contemporary E-trac might shine through  ;-))

Had steam traction been continued for longer than it was in America – and I think it could have made sense for, say, some 12, in some cases up to 20 more years, depending on individual case and railroad – mainly thinking of East Coast RRs, including the NYC, at least for the shorter time span, then freight train running should have been modernized from prevailing slow moving heavy drag freights towards a more speed conscious, in other words mileage conscious type of running of lighter loads by which steam loco types would regularly run well within their best working ranges. This would have asked for 60 to 70 mph regular freight train speeds – something the Union Pacific had done on their long stretches of flat land mileage and has become more recent practice with diesels of higher motor outputs. This would also have asked for modernization of line signaling to enable denser traffic – again just taking in advance things that had to come sooner or later with any kind of traction (i.e. not a thing just needed to extend steam traction).

Continuing a modernized steam traction through most of the 1960s would have changed the typical comparison from colloquial ‘old type steam by old-fashioned operation versus new type diesel by modern operation’ towards a ‘modern versus modern’ steam to diesel comparison. Clearly, with the changes in parameters, necessarily the results of the comparison would also have been changed – which in my view might very well have justified that limited extension of steam traction in modernized format.

With the distance of time we may agree to summarize that in the end it would all have boiled down much the way it did: steam would be gone today’s – maybe there would be a degree of wider spread electric traction in the East, yet in General, Motors of diesels would always be a-humming up and down and all about in America.

With best wishes for 2011

Juniatha

[Firelock76]

To Juniatha:  Wow! That's the first time I've ever read a doctoral dissertation in an on-line forum!  Seriously though, well thought out and well written.  One thing's for sure, if something comes along to make diesels obsolete, I don't think there'll be  many tears shed over them, certainly not as many as the steam engines got and still get.  People just love steam.  The head may say diesel, but the heart always says "steam rules!"

[Paul Milenkovic]

The idea of a 2-8-8-8-8-2 "quadraplex" to meet the low-speed traction of a 4-unit Diesel locomotive brings up an interesting question.  By applying steam to four sets of drivers, one could perhaps build a high-tractive effort low-speed machine, but its speed would be limited.

The idea of "booster" engines applied to single trailing truck axles on Hudsons and Northerns I think tried to address that problem in a limited way.  That is, one applies steam power to a larger number of axles at low speeds and then one applies steam power to a smaller number of axles at higher speeds, in the process having a machine that can operate over a wider speed range without exhausting the steam supply.

But these booster engines were only applied to single axles, and again, many railroads did not believe their complexity and attendant maintenance cost to be worth their performance.

[Anonymous]

Hey, Ho, wonderful written,

"This would then very much approach the end of the line for ‘conventional’ i.e. classic steam of basically Stephensonian concept."

and maybe that#s just the breaking point, traction motors on flexible trucks, electricity for perfect energy transmission,

unbeatable. Any power-source, small enough, could be instelled on that.  That killed the steam engine, in my mind.

Cheers

-lars

[erikem]

Juniatha

When comparing thermal efficiencies, one has to keep in mind, though, maximum efficiency figures are not what governs daily in-service consumption alone. First, railroad traffic often has engines working off their range of best efficiency with engine working loads varying widely; second, there are idling times which UIC tests on SNCF and DB have shown to bear heavy on diesel engines consumption, actually bringing average efficiency in fuel energy used for a defined scheduled work on a monthly basis down to figures by far less superior to steam’s equivalent figures than those of maximum efficiency for both diesel and steam would suggest! Clearly, the reason for this is in the practical need to keep diesel engines idling through short times of locomotive inactivity, such as train coasting, train stopped in station or at signal, train waiting for departure – but also while a diesel locomotive is on stand-by between two calls of service. Often depots have kept engines idling for hours to avoid having to start the following turns with a cold motor, or where frequent cold / hot / cold circles have led to excessive wear and in some cases even blocks cracking – very much a question of choice between two undesirable extremes: extra maintenance versus extra fuel consumption.

I may be mistaken, but I would think that switching service has the highest amount of time where the engine is idling. In the US, switchers were often the first steam locomotives on a railroad that got replaced by diesels, with the diesels producing very large improvements in fuel consumption over steam locomotives.

As for keeping diesels idling, the need is almost as much to maintain engine temperature as it is to keep the coolant from freezing. The coolant in the engine must be brought to a defined minimum operating temperature before a load can be applied to the engine.

- Erik

P.S. Welcome to the Forum!

[Juniatha]

Which speed and which viable concept for a 4 x 8-coupled proposal ?

 

Well, as to those old proposals of Henderson’s, you don’t necessarily have to reduce wheel diameter as compared to Mallets if you consider articulated frames and boiler and involve the tender to take part of the drive sets. Principally, this concept of articulated locomotive of which just the ‘simple’ and arguably more 'realistic' form was realized – the Triplex with but one drive set under the tender – might be classified as a giant form of articulated tank loco in that the aggregate has become one integrated unit that has lost the basic characteristics of a tender locos, i.e. –

–       separate power and supplies units that can readily be separated and coupled in a variety of combinations, say given engine to have smaller or larger tender;

–       constant adhesion mass as no supplies are carried on the power producing unit.

However, the question immediately arises what to do with that vast length available? Boiler design could hardly take advantage of it since there is a limit to how far length can be developed in relation to barrel diameter, or, more precisely: to free gas sectional area – which again is connected to size of grate, all of which were already stretched to the limit in large SE-Mallet types (that is why some of them showed a front end with front drive unit and cylinders substantially standing out in front of the boiler smoke box door – by an engineering viewpoint that just meant available space and mass not used for maximizing boiler size).

So, thought swings to ‘the other form' of articulated locomotive, the Garratt. Widely used in Africa and mainly realized as a flexible type of high t.e. on lightly laid and / or narrow gauge lines, there have been proposals to combine the Garratt concept with the Mallet concept to form a Mallet-Garratt – or Mallgarrett.

 

There you are with four drive units under one central bridge frame that holds the boiler! Since in a Garratt the boiler typically can be made shorter yet of even larger barrel diameter that in a Mallet of equivalent number of drive wheels and adhesion mass, such a Mallgarrett might j-u-ust have been possible and has, it seems, been put up as a proposal in various schemes of ‘steam-revival’ projects.

Such a proposition however would inherit certain disadvantages of both concepts, multiplying them into veritable engineering nightmares, for instance the Mallet-typical unsymmetric partition of the drive units into a flexible and a rigid one, in this case in a part-vehicle frame with a central pivot to distribute as evenly as possible the mass loaded on it by each end of the bridge frame. Such a multi-articulated framework structure would inevitably take up a lot of space as a large inactive mass! In other words: although of impressive length and complexity, such an engine would necessarily be ineffective in view of power per mass unit, awkward in maintenance and as a concept uncompetitive to engineering always aiming as it should at designing an answer of plain simplicity and elegance to the question at hand. In short: the marvellous Mallgarrett would be great for line side photographers but not as an answer to four units powered by Rudolf Diesel’s in revenue earning transportation.

Speaking of Peak Oil having passed us: what could coal burning power have to offer?

One simple answer: develop remote controls for steam and divide powers the Diesel way: i.e. four Mikes for four Diesel units – five Mikes for five Diesels up front, six for six in the middle of the train, seven for seven shoving at the back end … still somewhat less starting t.e. unit for unit by the steam version of multi-unit traction because of torque oscillation, somewhat larger total train mass, yet, arguably more power at speed – all-in-all competitive in performance  ;-)

 

However, I have always wondered about flange wear of such monster load trains in curves of lines climbing through the mountains. Well, just listen to those wheels squealing through Horse Shoe Curve on You Tube,

see à   http://www.youtube.com/watch?v=ogGSzzGvE6U&feature=related

Those trains wear heavily on wheel tires and on rails, too! Does it save labor and material costs in the long run if wheels profiles have to be turned more frequently, if even rails have to be replaced due to wear? How about breaking up those trains and go up and down the mountains smoothly without wheels screaming? Here comes your all American Simple Expansion Articulated, reloaded as maybe a 2-8-8-6 …

 

Regards

         Juniatha

                       

(edit: wrong link replaced)

[Paul Milenkovic]

On the subject of condensing steam cycles, how about this story

http://www.wired.com/autopia/2011/01/land-speed-record-attempt-gains-steam/

about a US team trying to beat the steam-powered land speed record recently set by a team from the UK?

The UK effort was pretty much the Stephenson steam cycle -- a lot of heat to boil a lot of water at moderate boiler pressure and then the steam goes out the stack -- although I thought their car had a turbine.  The US effort is an "advanced" steam cycle -- flash boiler, 3200 PSI, condensing -- but I know their power plant is a 6-cylinder Uniflow engine.  Oh, and they are going with "direct drive", relying on the high starting torque of a steam engine, instead of using electric drive.

The entire steam power plant -- flash boiler, uniflow piston engine, condensor -- is all into one compact stack, which is that thing behind the guy in aviator glasses wearing the red shirt.  They are also using waste heat from the condensor cooling air to preheat the combustion air.  OK, not a steam engine according to L.D. Porta's ideas, but interesting.

[Juniatha]

@ Paul:

 

So, both of them have it part-traditional / part-avantgarde – yet

vice-versa, for sure, on opposing sides of the Atlantic.

Relying on the starting torque of a piston steam engine for a speed range

that far stretched seems to me - well - stretching it a bit far ;-) or,

if you prefer, over-revving?

It is exactly with a high pressure condenser steam cycle where a turbine

is clearly superior to a piston engine, and simply for its light, compact unit

running free of any reciprocating mass forces would appear to me as t-h-e

logical choice for a vehicle aiming at nothing but speed.

Uuuuhh – and why that sharp off-set in frame width behind the front wheels,

makes for a weak point in the structure!

It could well have been a smooth backwards widening of the adjacent section.

  Stop, stop – I’ll cut it short here, lest I get into details …

 

Regards

 

              Juniatha

 

[Paul Milenkovic]

There are a number of factors at work here.

One is that the US Speed Record car uses a condensing steam power plant meant for more prosaic uses -- perhaps for a light utility truck or a small city bus that can run on a variety of bio-derived fuels.  The Speed Record car, it is claimed, is an effort to draw publicity to the engine, which they hope to use for much more than speed recrods.

Secondly, this is not to say that they won't use a multi-speed transmission in for the speed record.  But the group is claiming high torque with a compact, multi-cylinder radial piston uni-flow steam engine that a production car or truck may be able to utilize direct drive.

Thirdly, with respect to the claim that a (uni-flow) piston engine won't work with a condensing cycle, I don't get the impression that their condensor operates much below the atmospheric temperature and pressure of steam.  I can see where you need a turbine for the required volumetric efficiency to exhaust into "vacuum", but that is for stationary power plants where the condensor is cooled by lake or river water.  That their condensor inlet is not so low pressure is suggested by wanting to use the condensor cooling air outlet as combustion pre-heat.

Thirdly, perhaps the most radical part of what they are claiming is "water lubrication" and the ability to run a piston steam engine on the very high steam pressure and temperature they have in mind without the problems of coking the lubrication oil, removing the lube oil from the condensed water, and so on.

Their uni-flow engine is single-acting (there have also been double-acting uni-flow engines), and I suppose you can always lubricate a single-acting engine from the "back side" of the pistons by oil splash as in a conventional automobile engine, but that would leave a lube film that would get into the condensor water. 

That they are claiming 100 HP from a 350 lb package for the complete condensing steam power plant seems pretty impressive.  On the other hand, inventors and start-up businesses have been known to claim all manners of things, and Bill Lear's steam engine dreams in the 1960's didn't seem to go very far.

[Juniatha]

@ Paul

 

Well, that sure sounds interesting. Mass / power ratio reads respectable – although not exactly Indy Car nor Formula One level (which no one could reasonably expect).

Radial piston engine 

Hm – gee, that’s something I had been thinking about when studying engineering; it was a private idea ignited by the long & wide hoods of  1970s / 80s US full size sedans and focused on a gasoline radial piston engine, not steam, to be fitted lying flat under the hood. Usually, radial engines have odd numbers of cylinders per row or rather per disc – my idea was for a nine cylinder engine (it had to be very short stroke to contain width of block complete with cylinder heads).  Very soon, though, I found it proving a rather difficult proposition to use in a car for several reasons and by far not as suitable as it had appeared at first glance.

A) – as compared to external visual impression the engine compartment in a car is severely narrowed by the front wheels and suspension;

B) – as fitting as it would seem to sink a radial engine flat into the compartment like a giant cake – where does its crank shaft point to? It could be ideal for drilling holes into the road, but for driving the car you have to start with a spiral bevel gear;

C) – while accepting that, any sort of gearbox will tend to interfere with the exhaust lines downwards from the rearward cylinders.

Clearly, none of these problems exist in airplane applications – although not all is well with an engine exposing cylinders at right angle to direction of flight (was an axial piston engine ever used in aviation?).

Well – to cut it short: it could be done – by adequate amount of thinking, the above mentioned problems could be dealt with. Only – you should never ask  “What an advantage do you get by it ?(??)”    Perhaps mainly this one: Opening the hood, such an engine would provide a most unusual and stunning visual impression, with cylinders all around and with intake manifolds and fuel injection standing up on the engine block in a center-inclined circle. It would likely have a unique sound, too, with a soft vibrato caused by those inevitable variations in exhaust manifold bents and lengths. Unique, too:  In contrast to cars with longitudinally mounted engines, there would be no body leaning action on kick-down with a powerful engine and soft suspension, caused by engine block mounts taking up reaction torque – although there could be a certain degree of unwished nosing action instead – make it turn leftwards and it would fittingly encourage overtaking – *g*.

Water lubricated cylinders 

With modern ceramic compound materials that should be possible. In many ways technology of today much better supports the idea of a steam car than it did in Lear’s years. Yet, if all that will yield any advantage in fuel economy over modern gasoline or diesel engines of sophisticated optimized design I would not dare to bet on.

>> the claim that a (uni-flow) piston engine won't work with a condensing cycle << 

Oh, why shouldn’t a uni-flow piston engine work on exhaust to vacuum? Of course that would more radically clear cylinders of exhaust steam, with consequentially lower compression, thus less negative work. Yet, that would permit substantial down trimming of clearance volume and thus reduce mixing of used steam with live steam. Usually, uni-flow engines need larger clearance volume because on back stroke compression starts early – that impairs power output and efficiency because it tends to lower steam mean cylinder pressure and temperature.

That said, I’m still waiting for the steam airplane – it needn’t be a super-sonic transcontinental liner, a cute little city-hopper would satisfy my humble hopes … as a starter *g*.

With regards

Juniatha

 

[carnej1]

Juniatha

@ Paul

 

Well, that sure sounds interesting. Mass / power ratio reads respectable – although not exactly Indy Car nor Formula One level (which no one could reasonably expect).

Radial piston engine 

Hm – gee, that’s something I had been thinking about when studying engineering; it was a private idea ignited by the long & wide hoods of  1970s / 80s US full size sedans and focused on a gasoline radial piston engine, not steam, to be fitted lying flat under the hood. Usually, radial engines have odd numbers of cylinders per row or rather per disc – my idea was for a nine cylinder engine (it had to be very short stroke to contain width of block complete with cylinder heads).  Very soon, though, I found it proving a rather difficult proposition to use in a car for several reasons and by far not as suitable as it had appeared at first glance.

A) – as compared to external visual impression the engine compartment in a car is severely narrowed by the front wheels and suspension;

B) – as fitting as it would seem to sink a radial engine flat into the compartment like a giant cake – where does its crank shaft point to? It could be ideal for drilling holes into the road, but for driving the car you have to start with a spiral bevel gear;

C) – while accepting that, any sort of gearbox will tend to interfere with the exhaust lines downwards from the rearward cylinders.

Clearly, none of these problems exist in airplane applications – although not all is well with an engine exposing cylinders at right angle to direction of flight (was an axial piston engine ever used in aviation?).

Well – to cut it short: it could be done – by adequate amount of thinking, the above mentioned problems could be dealt with. Only – you should never ask  “What an advantage do you get by it ?(??)”    Perhaps mainly this one: Opening the hood, such an engine would provide a most unusual and stunning visual impression, with cylinders all around and with intake manifolds and fuel injection standing up on the engine block in a center-inclined circle. It would likely have a unique sound, too, with a soft vibrato caused by those inevitable variations in exhaust manifold bents and lengths. Unique, too:  In contrast to cars with longitudinally mounted engines, there would be no body leaning action on kick-down with a powerful engine and soft suspension, caused by engine block mounts taking up reaction torque – although there could be a certain degree of unwished nosing action instead – make it turn leftwards and it would fittingly encourage overtaking – *g*.

Water lubricated cylinders 

With modern ceramic compound materials that should be possible. In many ways technology of today much better supports the idea of a steam car than it did in Lear’s years. Yet, if all that will yield any advantage in fuel economy over modern gasoline or diesel engines of sophisticated optimized design I would not dare to bet on.

>> the claim that a (uni-flow) piston engine won't work with a condensing cycle << 

Oh, why shouldn’t a uni-flow piston engine work on exhaust to vacuum? Of course that would more radically clear cylinders of exhaust steam, with consequentially lower compression, thus less negative work. Yet, that would permit substantial down trimming of clearance volume and thus reduce mixing of used steam with live steam. Usually, uni-flow engines need larger clearance volume because on back stroke compression starts early – that impairs power output and efficiency because it tends to lower steam mean cylinder pressure and temperature.

That said, I’m still waiting for the steam airplane – it needn’t be a super-sonic transcontinental liner, a cute little city-hopper would satisfy my humble hopes … as a starter *g*.

With regards

Juniatha

 

Well, there is a historical precedent-The Besler Brother Steam Plane:

http://docs.google.com/viewer?a=v&q=cache:Dukpf2njQx0J:www.firedragon.com/~kap/SCD%26SA/Scd28.PDF+besler+steam+aeroplane&hl=en&gl=us&pid=bl&srcid=ADGEESiVSeV2wqN-_u08cUkztfF5pk1HXuEtHsnTvlcyr5hsjujM-PqERo3-Yawu0-NXnH54sG01b5U-oZ2nGp5U7QOcP1uFT6HrI5EQjv-neH8_rzQ661HQVTodwE9q0LKt1mSUoF6k&sig=AHIEtbQOvZgY7Tje7Ivh0CaA8nDjBdeLHQ

[Yardmaster01]

carnej1

Juniatha:

@ Paul

 

Well, that sure sounds interesting. Mass / power ratio reads respectable – although not exactly Indy Car nor Formula One level (which no one could reasonably expect).

Radial piston engine 

Hm – gee, that’s something I had been thinking about when studying engineering; it was a private idea ignited by the long & wide hoods of  1970s / 80s US full size sedans and focused on a gasoline radial piston engine, not steam, to be fitted lying flat under the hood. Usually, radial engines have odd numbers of cylinders per row or rather per disc – my idea was for a nine cylinder engine (it had to be very short stroke to contain width of block complete with cylinder heads).  Very soon, though, I found it proving a rather difficult proposition to use in a car for several reasons and by far not as suitable as it had appeared at first glance.

A) – as compared to external visual impression the engine compartment in a car is severely narrowed by the front wheels and suspension;

B) – as fitting as it would seem to sink a radial engine flat into the compartment like a giant cake – where does its crank shaft point to? It could be ideal for drilling holes into the road, but for driving the car you have to start with a spiral bevel gear;

C) – while accepting that, any sort of gearbox will tend to interfere with the exhaust lines downwards from the rearward cylinders.

Clearly, none of these problems exist in airplane applications – although not all is well with an engine exposing cylinders at right angle to direction of flight (was an axial piston engine ever used in aviation?).

Well – to cut it short: it could be done – by adequate amount of thinking, the above mentioned problems could be dealt with. Only – you should never ask  “What an advantage do you get by it ?(??)”    Perhaps mainly this one: Opening the hood, such an engine would provide a most unusual and stunning visual impression, with cylinders all around and with intake manifolds and fuel injection standing up on the engine block in a center-inclined circle. It would likely have a unique sound, too, with a soft vibrato caused by those inevitable variations in exhaust manifold bents and lengths. Unique, too:  In contrast to cars with longitudinally mounted engines, there would be no body leaning action on kick-down with a powerful engine and soft suspension, caused by engine block mounts taking up reaction torque – although there could be a certain degree of unwished nosing action instead – make it turn leftwards and it would fittingly encourage overtaking – *g*.

Water lubricated cylinders 

With modern ceramic compound materials that should be possible. In many ways technology of today much better supports the idea of a steam car than it did in Lear’s years. Yet, if all that will yield any advantage in fuel economy over modern gasoline or diesel engines of sophisticated optimized design I would not dare to bet on.

>> the claim that a (uni-flow) piston engine won't work with a condensing cycle << 

Oh, why shouldn’t a uni-flow piston engine work on exhaust to vacuum? Of course that would more radically clear cylinders of exhaust steam, with consequentially lower compression, thus less negative work. Yet, that would permit substantial down trimming of clearance volume and thus reduce mixing of used steam with live steam. Usually, uni-flow engines need larger clearance volume because on back stroke compression starts early – that impairs power output and efficiency because it tends to lower steam mean cylinder pressure and temperature.

That said, I’m still waiting for the steam airplane – it needn’t be a super-sonic transcontinental liner, a cute little city-hopper would satisfy my humble hopes … as a starter *g*.

With regards

Juniatha

 

 

Well, there is a historical precedent-The Besler Brother Steam Plane:

http://docs.google.com/viewer?a=v&q=cache:Dukpf2njQx0J:www.firedragon.com/~kap/SCD%26SA/Scd28.PDF+besler+steam+aeroplane&hl=en&gl=us&pid=bl&srcid=ADGEESiVSeV2wqN-_u08cUkztfF5pk1HXuEtHsnTvlcyr5hsjujM-PqERo3-Yawu0-NXnH54sG01b5U-oZ2nGp5U7QOcP1uFT6HrI5EQjv-neH8_rzQ661HQVTodwE9q0LKt1mSUoF6k&sig=AHIEtbQOvZgY7Tje7Ivh0CaA8nDjBdeLHQ

Radial aircraft engine,s were indeed used in automotive applications most famously in the US Sherman tank of WWII fame.  Now an external combustion engine of this layout is an intriging idea as it would provide a very smooth and virtually continuous torque application.  The only practicable problem being the drive system used to transmit power to the "road" be it pavement or rail.  Thanks for providing some interesting out of the box concepts.  Your grasp of the engineering principles involved is comendable.

                                                                                     Pat.

[Yardmaster01]

This is in addition to what I wrote above.  Virtually any automotive piston engine can be run in an external combustion capacity and has been done so many times that the subject does not warrant conjecture.

As to the proposition of a steam powered aircraft that MAY have come to pass in the late 1950's but the evidence is spotty at best due to the contoversial nature of the aircraft's power plant.  The aircraft in question was the B-36Q flying with a nuclear reactor on board.  The government documents released to date suggest that the plane flew with conventional power but with the reactor in a "hot" condition to evaluate the radioactivity in and around the lead lined crew compartment.

Other anecdotal evidence suggests that the reactor did indeed power two Westinghouse steam turbines operating in a Rankine cycle configuration driving line shafts through the wings transferring power to gearbxes to drive the propellers.  One of the original crew members on the test flights said the weight of the reactor, drive system and lead shielding necessitated the use of 20 RATO bottles plus the four jet engines to get the craft airborn in 11,000 feet of runway and precluded any useful payload.  On conventional power the aircrafrt was known as the NB-36H however this was later changed to the B-36Q with the supposition that this was when it was indeed nuclear powered.

After three weeks of testing the airframe had become radioactive to the point that no further testing was possible and the aircraft was subsequently scrapped.  To this day many documents regarding this interesting experiment remain classified and only the passage of time will bring out the entire story.

http://www.aviation-history.com/articles/nuke-american.htm

                                                                                                  Pat.

 

[Juniatha]

@ carnej1

@ yardmaster01

 

Gee, I’m surprised!

Frankly, wasn’t aware of steam powered air planes tested as early as in the 1930s.

Clearly, being able to escape into third dimension is one definite advantage of

‘steam traction’ over catenary guided electric traction …

Probably that’s why all of those incredibly modern high speed trains keep crawling

along at ground level at speeds of an old DC-3 …

*gg*

 

Regards

Juniatha

 

p.s.:

I noticed that the fonts that I used don’t seem to be saved with the posting,

so it’s only displayed properly on PC having those fonts.

Sorry if that has lead to incorrect display of my postings on other’s screens.

The fonts used were Garamond for the text and another handwriting font

for my name which I thought fitting.

I used Times Roman for this one now and Arial for the p.s. text, since they

are bread and butter universal automatic undeletable Microsoft basic fonts.

 

= J =

[carnej1]

Juniatha

@ carnej1

@ yardmaster01

 

Gee, I’m surprised!

Frankly, wasn’t aware of steam powered air planes tested as early as in the 1930s.

Clearly, being able to escape into third dimension is one definite advantage of

‘steam traction’ over catenary guided electric traction …

Probably that’s why all of those incredibly modern high speed trains keep crawling

along at ground level at speeds of an old DC-3 …

*gg*

 

Regards

Juniatha

 

p.s.:

I noticed that the fonts that I used don’t seem to be saved with the posting,

so it’s only displayed properly on PC having those fonts.

Sorry if that has lead to incorrect display of my postings on other’s screens.

The fonts used were Garamond for the text and another handwriting font

for my name which I thought fitting.

I used Times Roman for this one now and Arial for the p.s. text, since they

are bread and butter universal automatic undeletable Microsoft basic fonts.

 

= J =

Actually, the "incredibly modern high speed trains" such as the German ICE, French TGV, and the newest Japanese Shikansens are all faster than a DC3. You might be referring to Amtrak's Acela, which operates at Gooneybird cruising speed (150 MPH) for a part of it's route but that is due to speed limitations due to the 150 year old alignments it runs on...

Nothing on rails has a higher power-to weight ratio and faster acceleration than a straight electric..still, here's an idea that comines both electricity and steam:

http://www.google.com/patents/about?id=ClKAAAAAEBAJ&dq=%22locomotive%22+%26+%22electric%22+%26+%22steam%22

 

[Firelock76]

Actually, a fellow named Stringfellow built a steam powered flying model airplane in the 19th century.  It worked very well but never got past the model stage.  Around the turn of the 20th century Sir Hiram Maxim built a full size steam powered airplane, but the test flight failed and Sir Hiram was so frightened by the experience he never repeated it! 

[Juniatha]

Faster than old GooneyGoose

Well, al(w)right, that’s progress at last! Still, the Gooneybird would win the gutty sound contest wings down - *g* Quest for sound or lack of it is when elegy befalls electrics. Seems, on carefully arranged test runs the hasty super railcars have even challenged Connie for speed – when cruising on three engines as she had a soft spot for  …

 

Electrically fired steam locomotive

Oh, gee – *g*

During WW-II the Swiss converted a couple of 0-6-0 shunter tank engines to electrical heating, complete with pantograph on top of the cab. It was an emergency effort to fight dire shortage of coal with a minimum of rebuilding.

See http://www.skyrocket.de/locomotive/data/sbb_e3-3.htm

So, at least for some time then, no “choole shueble” (swiss for coal shoveling) on this granny steam engine.

Switzerland at those times was light years away from later welfare as the world’s – erh – treasure case.

 

Never mind

 

= J =

[JamesP]

I enjoyed the picture of the Swiss conversion!  There was an early live steam model locomotive sold that was fired with an electric heating element, and Jenson also sold versions of their stationary steam models with electric heating elements.  I can understand the Swiss taking the desperate measure of converting a steam loco to electric heating during war, but that patent... even after reading it, I don't understand what the inventor hopes to accomplish with the new electrically fired steamer.  Alternating current, creating steam, driving the wheels, but also spinning an onboard turbine to generate additional HEP and charge batteries?  That's a lot of complexity just to lose efficiency compared to a straight electric...IMHO! 

 - James

[AltonFan]

carnej1

 

 

 

Nothing on rails has a higher power-to weight ratio and faster acceleration than a straight electric..still, here's an idea that comines both electricity and steam:

http://www.google.com/patents/about?id=ClKAAAAAEBAJ&dq=%22locomotive%22+%26+%22electric%22+%26+%22steam%22

I'm having a hard time seeing the practical value of this locomotive.  Most of the benefits of electric locomotives are due to the use of traction motors.  Using electric as "fuel" for what amounts to a rod-driven steam locomotive seems to cancel out those benefits, and create a Rube Goldberg level of needless complication.

[Juniatha]

At least to model railroaders the electrically run ‘steam locomotive’ is nothing new - *g*

 

AltonFan wrote, to quote:

>> I'm having a hard time seeing the practical value of this locomotive. <<

 

Well, it says under “Background of the invention”, at 0005, quote:

>> Steam locomotives are old and well known. <<

E-hm – now, while emotionally inclined individuals such as me would tend to object to that claim, proposing that steam locomotives never get ‘old’, they just turn into classics, some into myths even, I agree this might be considered a side track to the issue.

So, at 0006 it continues saying:

>> Electric locomotives are also old and well known. <<

Ok, I grant that. It may be somewhat blunt, not too courteous, not too polite, but at least there is a sense of poetic justice!

               While some have undoubtedly been remotely haunted before by an inexplicable suspicion that this might be so – what does it mean to tell us in this context?

Coming up in the same paragraph, quoting excerpts:

>> These electric generating stations transform power from coal fields … into electric energy … The electrical energy is then transmitted to the locomotive … <<

Ok. The paragraph ends with:

>> In view of declining coal reserves, a need exists for an electrically powered steam locomotive according to the present invention. <<

 

I see … erh – or maybe not quite.

 Umh, I think I might have ventured to ask Jules Verne about it – unfortunately I don’t have his e-mail address. Yet, then again, he might not have been delighted by the disturbance in his absolute Zen remoteness on board of the Nautilus, broken only by some occasional erudite conversations with captain Nemo in the library, sipping an 1899 Chateau Lafayette …

 

Yet, seriously speaking:

With electric high speed train service based on coal as primary thermal power, because of vast power outputs and multiple energy conversions and transmissions of electricity , including power sub-stations along the lines to contain voltage drops, those trains consume roughly about the same amount of primary energy per productive ton-mile, i e coal per ton-mile in this instance, as the mighty Super Power steamers once did.

Well, yeah, they’re going faster now – much faster in top speed, surprisingly mildly faster in start to stop traveling speed (acceleration / deceleration times, speed restrictions going out of / going into central stations, line speed restrictions and traffic, speed restrictions passing line-side stations, etc all tend to interfere).

 

Regards

 Juniatha

[Paul Milenkovic]

With electric high speed train service based on coal as primary thermal power, because of vast power outputs and multiple energy conversions and transmissions of electricity , including power sub-stations along the lines to contain voltage drops, those trains consume roughly about the same amount of primary energy per productive ton-mile, i e coal per ton-mile in this instance, as the mighty Super Power steamers once did.

The argument had been made that Chapelon's best steam locomotives (maybe 10-11% thermal efficiency) were competitive with coal-fired power plants (of the day), especially when transmission losses are taken into account.

The best figures I have seen for single-expansion steam would put efficiency, at best, around 7-8 percent.  Modern coal-fired power plants are in the 30 percent efficiency range with the latest supercritical steam cycle plants about 40 percent (with respect to low heat value -- LHV -- of the coal).  My guess is that worst-case transmission loss is 50 percent (full electric power at most remote location from substation), making the electric train at least 3 times more efficient than Super Power steam.

[BigJim]

Did any of you read "The Thermodynamic Closing of the Great Steam/Diesel Debate"?

[Paul Milenkovic]

BigJim

Did any of you read "The Thermodynamic Closing of the Great Steam/Diesel Debate"?

No, but the steam/Diesel question will never be answered on thermodynamics.  It is were, we would no longer have coal-fired steam-cycle electric power plants.

The question will be answered on a combination of thermodynamcs, capital, and maintenance combined with the compliance with environmental regulations.

Those guys (the people with the compact automotive steam power plant) are claiming 21 percent efficiency.  Yes, that is much less than what Diesels can achieve, but they are claiming a multi-fuel capability (although not yet solid fuel) that Diesels don't have.

[Juniatha]

Hi -

 

What you write is pretty much what I meant, if you come to think of it:

With a higher efficiency and a similarly higher demand of energy at the same time you end up at much the same primary fuel consumption.

For example: using the quoted figure of three times higher efficiency in electric over steam traction; the power applied by these high speed trains is about (approx., for rule of thumb) four times that of steam typical for the 1940s Super Power types, i e it compares like 20000 to 5000 or if you prefer 16000 to 4000 hp at wheel rims. Yep - it takes a lot of power to run about twice as fast (top speed, not start to stop average) than the fastest steam powered trains! Logically, this rule of thumb comparison would tend to indicate electric high speed train rather use more not less primary (coal heat content) energy per train mile, then. You could go on to make this comparison per ton-mile / ton-km for metric units, or per passenger-mile / passenger-km which is what matters in the end as revenue is concerned.

I'm afraid the quoted losses of electric energy from power plant to pantograph of el loco are a bit optimistic and do not include energy demand by intermediate high voltage input stations needed in view of keeping line voltage (relatively) constant in spite of fluctuating, yet generally very high consumptions at peak traffic times with heavy surges of demand by traffic fluctuations and random numbers of locomotives all in one area happening to draw peak currents each at the same time or at overlapping times.  

Further, a fair comparison of the three major concepts of traction would need to include capital costs for installation of electrification which is by no means less than formidable. This is why full electrification - however desirable from a technical standpoint - was not even achieved on large state owned railway networks in Europe, practically all of which did not have to work on a strictly self-supporting financial basis but were more or less heavily supported by 'their' states -  at least from the period of transition from steam in the 1950s until the 1990 (in other words, they 'produced' deficits - in spite of or independently from E-trac). Taking into account these immense first costs and debit cost of capitalization a private enterprise would have to pay for, then it might become indeed questionable how many decades it takes until this type of investment will make a mean profit. Yet, in a larger, more general view of national economy it made good sense to modernize the railways mainlines this way taking into account what would have been the alternatives: even more truck carried transport on roads, even higher fuel consumption, even higher costs of road building and maintenance, even higher mortal rates in accidents etc ...

In my point of view - i e from an engineering perspective - electrification is the most elegant way to boost rail traffic to maximum performance. However that does not mean to say this always is the most economic way nor the optimum feasible way for private enterprises who have to have an eye on best return for capital investments strictly focussing on their future as a company. 

A side remark:

Locomotive costs, traction costs are but a fraction of overall costs of running a railroad. In France, the railway most successful in revenue earning during the age of steam was the one with the most uninspired locomotive development, the PLM with a fleet of steam locomotives in their technical features typical examples of the 'good enough' engineering much belated with steam - while the Paris-Orleans, where Chapelon introduced his innovation of highly efficient engines was about the least profitable one. This is not because it was more economic to have 'bad' locomotives than to have 'good' ones, but it puts a light on relative unimportance of locomotive running costs as compared to other factors - even more so on relative unimportance of efficiency of a group of top quality types of locomotives, again rather insignificant in numbers relative to the total fleet of locomotives. (Where they definitely do make a difference is in running top services, advertising the company and earning a good reputation) Likewise, in Germany the Prussian State railway with a parc of steam of strict if not austere simplicity was by far the leading railway in revenue earning per ton-km of train service compared with any other of the pre-Reichsbahn State railways. The Italian state railways ad another disturbing shade to the picture: they were ranking high among the economically most hopeless railways in Europe - in spite of early transition from steam to electric traction. They have gone on to remain so in recent years and do not really threaten to compromize on their social importance in keeping unemployment down - no matter which government. That it wasn't early type of electrification that was to blame is well proven by the Swiss railways where likewise early electrification in contrast was the starting point of a lasting story of enormous success, still continuing with solid common sense progress, if lacking some of the sparkle put up by the French, naturally.

With regards

 

Juniatha

[Firelock76]

To Juniatha:  Dear lady, you hit the nail right on the head with your last post, specifically the references to the French railroads, to whit:  Whether a railroad makes money or not depends on what it's hauling not what it hauls it with!  Steam, diesel, electric, it doesn't matter.  If the freight's not there neither is the revenue.  Going diesel couldn't save the Pennsy or the New York Central when the shippers dissapeared.  But who knows, they might have lived if they went into the rip-roarin' steam excursion business!  Someone once said, "call it transportation and people get bored.  Call it a RIDE and you have to fight them off!"