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Could steam make a comeback?

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Posted by wsherrick on Thursday, March 27, 2008 8:42 PM
 GP40-2 wrote:
 MichaelSol wrote:

Al Krug has this to say...



Al Krug didn't test AC's on the Mountain Sub...I did. Like I said, the figures I gave are from ACTUAL service...What don't you guys understand about ACTUAL...

MY aren't we combative!  I will answer your question about the Y6b on the B&O's west end when you tell me how often a single AC unit goes over the grade and how much it pulls. Or is it more than one unit at a time? And at what speeds does the AC unit produce this "continous tractive effort," and what speeds do these engines produce these horsepower ratings?  Any decent size Northern can produce 4000 horsepower for a wide range of speeds

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Posted by MichaelSol on Thursday, March 27, 2008 8:41 PM
 GP40-2 wrote:
 MichaelSol wrote:

Al Krug has this to say...



Al Krug didn't test AC's on the Mountain Sub...I did. Like I said, the figures I gave are from ACTUAL service...What don't you guys understand about ACTUAL...

As regards actual fuel costs today ... right on! Those things actually are important. The best machine in the world is worthless if it costs too much trying to do the job ...

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Posted by GP40-2 on Thursday, March 27, 2008 8:37 PM
 MichaelSol wrote:

Al Krug has this to say...



Al Krug didn't test AC's on the Mountain Sub...I did. Like I said, the figures I gave are from ACTUAL service...What don't you guys understand about ACTUAL...
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Posted by GP40-2 on Thursday, March 27, 2008 8:33 PM
 wsherrick wrote:
... CSX are buying DC motors for the mountainous coal regions for drag service for some reason...


That is 100% wrong.

You still didn't answer my question about the Y and A on the West End...
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Posted by MichaelSol on Thursday, March 27, 2008 8:26 PM

Al Krug has this to say:

"One night I was running a freight up hill at 7 mph with a Dash 9-44CW on the point. I had previously calculated that we should have gone up the hill at 11 mph, so why were we only doing 7 mph? The rail was slightly frosty. I punched up the loco monitor screen on the computer. It showed that this supposedly 4400 Hp unit was only putting out 2930 HP!!! It had derated to prevent slipping in spite of the sanders being on. So the adhesion factor of this loco at that time was not the touted 36-43% but instead only 22%. The railroad had paid for a 4400 HP locomotive with 36% adhesion but was only getting a 2930 HP locomotive with 22% adhesion. The common SD40-2 would have done as good or better in this situation than the hi-tech wonder. This was not a one time occurrance. I have seen similar performances on many occasions."

"If you haven't been paying attention you might think that the new 6000 HP single unit locos are destined for heavy haul service. True they are all heavy 6 axle units. But that is because the weight is needed to put that 6,000 HP to the rail without slipping. A 6,000 Hp unit that weighs 420,000 lbs and can attain a 43% adhesion factor has an adhesion of 180,600 lbs. The 6,000 Hp diesel engine can deliver that 180,600 lbs of Tractive Effort at a speed of 13 mph. Below that speed you cannot use full throttle on these locos because they will slip. That was for an astounding adhesion factor of 43%. What if they cannot maintain that extreme level of adhesion? What if they "only" get 36%? 36% of 420,000 lbs is 151,200 lbs of TE. The 6000 hp diesel can deliver that TE at 15 mph so the loco cannot operate below 15 mph in full throttle without slipping. At an adhesion factor of 30% the lowest full throttle speed is 18 mph. If the rail is wet or frosty can these modern marvels maintain even a 30% adhesion factor? My experience with 4400 Hp units is a definite no. The C44s often have trouble maintaining 22% adhesion with bad rail conditions. If a 6,000 Hp unit gets down to 22% adhesion it can only operate at full throttle above 24 mph! Thus if you want these behemoths to reliably move your trains over the hills in all kinds of weather you had better dispatch them with trains light enough that they can maintain 24 mph or greater on your steepest hills. That means they are only useful for trains such as intermodals which get a high Hp to tonnage ratio. When it is frosty they won't work on heavy freights or coal or grain trains which routinely pull up the hills at 10-12mph. "

"Modern locos such as SD70MACs and C44s claim adhesion factors of 36 to 43%! They do this by using sophisticated anti-wheelslip circuits. These circuits allow the wheels to spin slightly faster than the rail speed warrants. It is called creep. Strangely enough, a creeping wheel has a higher factor of adhesion than a stationary or rolling wheel. Thus in theory two 6,000 HP SD90s weighing 420,000 lbs each and achieving an adhesion factor of 36% will produce a TE of 302,400 lbs and should pull the train up the hill at 15 mph.

"However, in my experience you cannot count on that 36% adhesion factor in all types of weather and rail conditions. On wet or frosty rail these units slip and you stall. And when you stall you had better set the train airbrakes in a hurry or the train will slide these units back down the hill. On the other hand I have had C44s, SD90s and SD70MACs absolutely astound me with what they are pulling. At times they attain greater than 40% adhesion on dry, sanded, rail. It is that "at times" that concerns me. You cannot count on them to do that reliably time after time. "

Interesting. I can imagine what modern electronic control technology might do for a reciprocating steam engine. On the other hand, maybe I can't: Steam was never my cup of tea. Of course, given that the Diesel-electric was deficient in many ways compared to Steam at the outset, operating costs made the difference. The same logic may hold true today, with the opposite results ....

 

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Posted by wsherrick on Thursday, March 27, 2008 8:21 PM

I've run everything from a 2-8-0 to a Berkshire, mikados, worked on many other steam locomotives, GE U Boats, Most models of EMD's and Alco Diesels.  I see these AC locomotives daily and I still don't see a single AC unit pulling the same tonnage that any of the largest steam power and you can't tell me that these units are not slippery devils, so I guess I do know what I'm talking about.  I know GP 40, that you have totally imbibed the Diesel kool aid, but that's fine, I also run into people like you everyday as well.  No hard feelings there pal.  By the way NS and CSX are buying DC motors for the mountainous coal regions for drag service for some reason. I heard that from a CSX employee just this morning as we were discussing this very topic.

PS: I have worked on a Class A.

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Posted by GP40-2 on Thursday, March 27, 2008 8:08 PM
 wsherrick wrote:
These six axle AC diesels have the same problem as the others when it comes to the power to weight ratio.  The diesel doesn't give the 6000 horsepower until it is in notch 8.  Therefore that horsepower isn't available for starting the train.  The ability of a locomotive to pull regardless of type depends on how much weight is on the drivers.  The diesel doesn't have the weight on the drivers to take advantage of its theoretical tractive effort...


For the record, CSX's AC units produce 200,000 lbs continuous TE with the latest GE software upgrades. That's MEASURED TE in actual service conditions, not theoretical. The 4400 GEs produce 4150 HP at the rail and the 6000's produce 5600 HP at the rail. Again, measured in actual service. Wsherrick, it is obvious you don't have any working experience with AC units, so please don't pass your opinions off as fact. Thank You.

P.S. I would like to see a single Y6 or Class A to even try to attempt the tonnage a single AC can pull over the old B&O West End.
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Posted by wsherrick on Thursday, March 27, 2008 8:01 PM
Thanks a lot Selector Smile [:)]  This paper along with Brown's report and a whole lot of downloadable material can be found in the "References & Links," section at the 5at site. Mr. Sol I would like to hear your thoughts on this paper if you care to study it.
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Posted by wsherrick on Thursday, March 27, 2008 7:45 PM

I just checked the 5at project site and they have just posted one of Wardales exhaustive works on the theory and practice of modern steam.  For those of you who have an engineering bent and can understand pages of Calculus ( I only took 2 semesters of it in college) These papers have complete diagrams and calculations for the Gas Combuster Firebox, Lempor exhausts, boiler specs, in short the whole ball of wax where he lays out the probabilities and potiential for new steam.  I'll try and post a link, I'm not too good at it but here goes;

 http://www.5at.co.uk/

(corrected by selector.  Just type/paste it, and then immediately hit "enter" on a Windows system.)

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Posted by Modelcar on Thursday, March 27, 2008 4:04 PM

Michael....I'm simply making the comparison {on automobile gasoline engines}, and getting back to the era right before the typical catalytic converters were installed, fuel economy {and performance}, were at a low point.....1973-74 time bracket.  The emission controls that were in place {and required}, were reducing capable performance of  the auto engines.  So my statement then, intends to relate...performance and economy were advanced from the low point when the catalytic converters were put into production and made part of the powertrain package and replaced the anti pollution methods previously in place.

I agree, catalytic converters are not going to increase performance and economy compared to an engine with no polution equipment installed.

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Posted by wsherrick on Thursday, March 27, 2008 2:39 PM
 erikem wrote:
 MichaelSol wrote:
 erikem wrote:

For road power, steam's advantage when the need was for horsepower as opposed to tractive effort, where many of the new AC locomotives are being used where the need is for tractive effort. If I recall correctly, two 6 axle AC locomotives can generate as much starting tractive effort as three Big Boys. 

For machines with the same weight on the drivers, Steam exceeded the tractive effort output of a Diesel-electric above 6-7 mph. Above 19 mph a Steam engine exceeded the Diesel-electric in both tractive effort and horsepower and the margin of both increased as speed increased.

In the range 0-7 mph, the Diesel-electric could generate more tractive effort, but the rate of loss in its ability to do so was very high. In that same range, the Steam engine generated more TE than it did at higher speeds, as with the Diesel-electric, but the rate of loss in the ability to generate Tractive Effort was much lower.

Because of that, at 30 mph, the Diesel-electric had lost 82% of the TE it generated at 2 mph, while the Steam engine lost only 20% of the TE it generated at 2 mph, and exceeded the TE output of the Diesel-electric by a substantial margin. Notably, at 30 mph the Steam engine is generating 100% more Tractive Effort than the Diesel-electric machine.

At 30 mph, the Steam engine also exceeded the hp of the Diesel-electric, by 20%, and continued to generate increasing horsepower to 60 mph, exceeding the Diesel-electric by as much as 30-35%.

For locomotives pre-dating the EMD super series traction control, the steamers could deliver higher sustained tractive effort for a given weight on the drivers. After that, the diesel's did better. A modern 6 axle AC locomotive can generate a higher continuous tractive effort (at low speeds) than a Big Boy, and weigh about as third as much. A 6,000 HP version will produce almost as much drawbar horsepower as the Big Boy and cost about the same as inflation adjusted price for a Big Boy.

The locomotives with the worst fall-off of drawbar power with speed were the electrics running off a DC electrification - the operating characteristics of a DC series motor mandated that the current decrease as speed went up for a constant supply voltage (hence a drop in power). One way of getting around that was field shunting. 

These six axle AC diesels have the same problem as the others when it comes to the power to weight ratio.  The diesel doesn't give the 6000 horsepower until it is in notch 8.  Therefore that horsepower isn't available for starting the train.  The ability of a locomotive to pull regardless of type depends on how much weight is on the drivers.  The diesel doesn't have the weight on the drivers to take advantage of its theoretical tractive effort and thus will slip helplessly when starting in many cases. 

Also, if these locomotives are so vastly superior in pulling power and horsepower output then you would see one unit pulling the same tonnage that a Challenger, Big Boy, Class A or other comparable steam locomotive but you don't. You see three of them pulling the same tonnage that the single steam locomotive pulled on a regular basis.  One of these diesels can't take a 15,000 ton coal train like a Class A did by itself everyday.

Now we are talking again about steam from a half century ago and comparing them to the newest diesels out there. The modifications done by Chapleon, Porta and Wardale to existing locomotives caused them to double their thermal efficiency, double their horsepower, and cut fuel consumption by astounding amounts. These modifications were done with existing locomotives which greatly limited what could be done within the parameters of the original design.  The potential for development of the standard steam locomotive is vast, whereas diesel technology is moribound when comes to increasing performance, fuel economy or anything else for that matter.  I know its hard for those who worship at the alter of EMD to accept this but it's the truth. All the stats, graphs, references given here overwhelmingly support this claim.  I am reminded of a remark made by David Wardale when he was over here working on the 614 back in 1985.  He said a simple modification of 614's valves and steam passages would give the 4-8-4 more horsepower than the Big Boy.  That remark has stayed with me over the years as an insight of what potential lies dormant in the steam locomotive. 

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Posted by wsherrick on Thursday, March 27, 2008 2:09 PM

For those who contribute without reading the whole thread.  The Porta Firebox is a simple application based on the nature of combustion.  It decreases the consumption of coal of an average of 25 to 30%.  On the Red Devil, The Argentina and other locomotives fitted with this firebox consistently show these savings in fuel.  Under optimal conditions the Red Devil showed a decrease of 65% in fuel consumption.  Also the emissions from the locomotive is well below what is required by the EPA.  There is no need for scrubbers or any other extra stuff to be added to the maintenance and first cost of the locomotive.  Diesels will NEVER be able to meet these standards and the added equipment required to make them come somewhere close will only make the first cost of the unit more and increase the already high expense in maintenance.

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Posted by MichaelSol on Thursday, March 27, 2008 11:39 AM
 Modelcar wrote:

...Michael, I believe the catalytic converters increased the efficiency of the automotive engines {gasoline}, back about 1975.  Their use allowed other pollution removing means to be lessened on engines promoting the ability to retune said engines for better performance and economy.  Said pollution was then "cleaned up" by the converters before passing out into the atmosphere.

Wouldn't the effect on diesel engines be similar.....?

My understanding, which is very limited in this area, is that catalytic converters are in the exhaust cycle -- after the engine energy is delivered to the powertrain, and so cannot contribute to energy conversion efficiency except in a negative fashion. Since the effectiveness of the converter depends on a variety of fuel conditions, the converter also "controls" -- through some more electronics -- certain engine functions to minimize combustion byproducts -- and this is almost always at the sacrifice of engine efficiency.

The trick has been to develop catalytic converters that reduce emissions while minimizing the effect on engine efficiency, and these are often characterized as "increasing engine efficiency" which they do, sort of, compared to older pollution control equipment, including previous catalytic converter models, but not compared to an engine which is designed solely to maximize fuel efficiency.

Figures I recall seeing -- and its been quite a while and this could be completely haywire -- reported fuel efficiency losses as high as 10%, in addition to the cost of the catalytic converter which, for production automobiles, can run as high as 5-8% of the retail cost of the automobile. These are expensive additions to equipment, and add their own maintenance costs as well as reducing fuel efficiency.

On automobiles, my limited understanding is that a typical catalytic converter doesn't measure up to the typical engine life, and must be replaced at least once, often twice, during the economic service life of a typical automotive engine. Today's converters may have a better life span, but what that might mean in 2017 when Diesel-electric locomotives will be required to have them is, well, a long way off ... for good reason ...

And this was the quantum leap for coal combustion from the standpoint of Steam locomotion: discovering a straightforward combustion technology -- fluidized bed -- that doubled efficiency and minimized emissions to something below what the very best and most expensive catalytic converter technology can achieve.

 

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Posted by JonathanS on Thursday, March 27, 2008 11:21 AM
 MichaelSol wrote:

 erikem wrote:
  A power plant has a lot more room for pollution controls than a locomotive - to be fair this is also true for diesels, there's not much room to put a catalytic converter on a diesel locomotive.

Ah, but the catalytic converters are required on Diesel-electrics after 2017. There is a reason the requirement is out there so far, but presently, the converter is the only way to bring the diesel engine into compliance with emission standards. This will reduce the economic efficiency of the Diesel-electric locomotive.

On the other hand, the fluidized bed method of coal combustion has proven successful at bringing the combustion efficiency of coal up to 13%, and reducing emissions that TVA built its most recent plant without the catalytic converters -- the first one -- and it is burning cleaner than the remainder of its plants -- all with the catalytic converters.

Catalytic converters are much smaller, lighter, less expensive to purchase and maintain than are scrubbers.  Catalytic converters do not produce waste solids that require disposal as do scrubbers and fluid bed combustion systems. And at the end of thier life catalytic converters are valuable as scrap, scrubbers are not.

Fluid bed combustion requires two feed systems.  So you must not only carry your fuel, you have to carry the lime (usually) that will react with the sulfur.  Fluid beds are much larger than normal locomotive combustion chambers.  The fluidization requires that a lot of energy be expended before you even get combustion so the overall energy efficiency is lower because of the parasitic loads.  And you have to have a huge dust collection system, which is expensive to buy and maintain and requires more energy to operate.  And at the end of the day not only must you replenish the coal and lime, you must remove and dispose of the calcium sulfate which contains significant amounts of mercury and other hazardous substances.

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Posted by Modelcar on Thursday, March 27, 2008 11:05 AM

...Michael, I believe the catalytic converters increased the efficiency of the automotive engines {gasoline}, back about 1975.  Their use allowed other polution removing means to be lessened on engines promoting the ability to retune said engines for better performance and economy.  Said polition was then "cleaned up" by the converters before passing out into the atmosphere.

Wouldn't the effect on diesel engines be similar.....?

Quentin

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Posted by MichaelSol on Thursday, March 27, 2008 8:42 AM

 erikem wrote:
  A power plant has a lot more room for pollution controls than a locomotive - to be fair this is also true for diesels, there's not much room to put a catalytic converter on a diesel locomotive.

Ah, but the catalytic converters are required on Diesel-electrics after 2017. There is a reason the requirement is out there so far, but presently, the converter is the only way to bring the diesel engine into compliance with emission standards. This will reduce the economic efficiency of the Diesel-electric locomotive.

On the other hand, the fluidized bed method of coal combustion has proven successful at bringing the combustion efficiency of coal up to 13%, and reducing emissions that TVA built its most recent plant without the catalytic converters -- the first one -- and it is burning cleaner than the remainder of its plants -- all with the catalytic converters.

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Posted by erikem on Thursday, March 27, 2008 1:55 AM
 MichaelSol wrote:
 erikem wrote:

For road power, steam's advantage when the need was for horsepower as opposed to tractive effort, where many of the new AC locomotives are being used where the need is for tractive effort. If I recall correctly, two 6 axle AC locomotives can generate as much starting tractive effort as three Big Boys. 

For machines with the same weight on the drivers, Steam exceeded the tractive effort output of a Diesel-electric above 6-7 mph. Above 19 mph a Steam engine exceeded the Diesel-electric in both tractive effort and horsepower and the margin of both increased as speed increased.

In the range 0-7 mph, the Diesel-electric could generate more tractive effort, but the rate of loss in its ability to do so was very high. In that same range, the Steam engine generated more TE than it did at higher speeds, as with the Diesel-electric, but the rate of loss in the ability to generate Tractive Effort was much lower.

Because of that, at 30 mph, the Diesel-electric had lost 82% of the TE it generated at 2 mph, while the Steam engine lost only 20% of the TE it generated at 2 mph, and exceeded the TE output of the Diesel-electric by a substantial margin. Notably, at 30 mph the Steam engine is generating 100% more Tractive Effort than the Diesel-electric machine.

At 30 mph, the Steam engine also exceeded the hp of the Diesel-electric, by 20%, and continued to generate increasing horsepower to 60 mph, exceeding the Diesel-electric by as much as 30-35%.

For locomotives pre-dating the EMD super series traction control, the steamers could deliver higher sustained tractive effort for a given weight on the drivers. After that, the diesel's did better. A modern 6 axle AC locomotive can generate a higher continuous tractive effort (at low speeds) than a Big Boy, and weigh about as third as much. A 6,000 HP version will produce almost as much drawbar horsepower as the Big Boy and cost about the same as inflation adjusted price for a Big Boy.

The locomotives with the worst fall-off of drawbar power with speed were the electrics running off a DC electrification - the operating characteristics of a DC series motor mandated that the current decrease as speed went up for a constant supply voltage (hence a drop in power). One way of getting around that was field shunting. 

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Posted by erikem on Thursday, March 27, 2008 1:38 AM

 rrandb wrote:
The fact that most electricity is produced by coal and not diesel tells which is most cost effective period.

There are a few caveats here.

Number One: Almost all steam plants make use of condensers to reduce the back pressure to about 1 psi absolute (about 14 psi of vacuum at sea level). This helps enourmously with thermal efficiency. Even then, typical thermal efficiencies for modern coal plants are around 33% as compared to 60% for the latest generation of combined cycle plants.

Number Two: The furnaces on a coal fired plant are quite large, not practical to shrink down to locomotive size (though a gasifier may help). The primary heat transfer mechanism in the furnace is radiation - where a locomotive makes greater use of convection (though radiation dominates in the firebox and combustion chamber.

Number Three: A power plant has a lot more room for pollution controls than a locomotive - to be fair this is also true for diesels, there's not much room to put a catalytic converter on a diesel locomotive.

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Posted by wsherrick on Wednesday, March 26, 2008 1:52 PM
 ExBNSF Manager wrote:
It wont ever happen.

With every major shipper getting a tax cut on fuel and shipping having a fuel surcharge that is past on to the consumers, there is no reason why they would care. Haven't you ever wondered why diesel is higher than unleaded now? It is what is supporting the US economy every time you go by a candy bar. 99% of the US market relies on products that are shipped on diesel surcharge. No reason for corporate to make a move for another fuel. The only thing that is hitting them now is the EPA and California for polution.

I don't mean to single your comment out.  Don't take it personally.  You are only illustrating the totally block headed view that is guiding the entire transportation industry.  So basically as long as the transporters can gouge shippers and then the shippers can get tax breaks because they are being gouged, then that's the way the World should rotate and no other ideas or progress can be made until the industry is forced to.  Much like when the Railroads were forced to adopt air brakes and automatic couplers.  The industry then couldn't see that these innovations would save them millions in lost productivity, loss due to wrecks derailments and loss of life.  Today the mindset is still the same. "We're not gonna do anything until we have to,"  As I stated earlier in this thread, innovative thinking is punished in the rail management world.  I found out about that the hard way.  Young men with ideas get hammered for, "rocking the boat."  Regional railroads, Terminal Railroads and many short lines can't benefit from fuel surcharges and it is from there that the change will come I believe.  And I don't find the evidence that shippers are compliant with the whole fuel surcharge idea as the Congressional Record shows. A year ago the Congress found that the Class Ones were overcharging for fuel and a limit has been placed on that.  The pressure to reign in exorbitant fuel surcharges will only increase as time wears on.  And if the Democrats get their rail re-regulation bill off the ground, forget it.

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Posted by carnej1 on Wednesday, March 26, 2008 11:12 AM
[quote user="Kevin C. Smith

I'm interested if any shortlines that operate steam tourist locomotives (who was it that bought those Chinese made locomotives a few years back?) will find them more economical than their diesels...

 

How about R.J Corman? They have several coal hauling operations and they just took delivery of a QJ...It's an interesting thought.......

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Posted by Kevin C. Smith on Wednesday, March 26, 2008 2:38 AM
 wsherrick wrote:

Thanks for all of your effort to post these graphs and other statistics.  I know from years of experience and by empirical observation of the locomotives I have operated about how any given steam locomotive of equal weight to a diesel, blows the diesel away after you get it above 5 MPH or so.  I know that diesels have supposedly more tractive effort at starting than the steam engine with approx the same weight on the drivers, but what you find out when you run the diesels is that they often can't take advantage of this tractive effort because of the power to weight ratio. EMD's are especially bad in this area. The diesel easily slips at starting because there is not simply enough weight on the driving wheels to take advantage of it.  Often times one has to have the engine pull against the independent brake, peg the Amperes way up into the danger zone and get the train started that way because otherwise the diesel simply can't start the train without excessive slipping or if it gets started can not maintain the pull necessary to keep the train rolling because the tractive effort and horsepower curves drop off so quickly. So often times it takes two engines to pull what is in the theoretical ability of one engine.  The steam engine once it gets the train rolling can generally accelerate it and pull it with ease.

I seem to remember reading the comparison that, "A diesel can start any train it can pull and a steam engine can pull any train it can start."

I'm interested if any shortlines that operate steam tourist locomotives (who was it that bought those Chinese made locomotives a few years back?) will find them more economical than their diesels...

Also, wasn't the Sierra Railroad experimenting with an almost all biodiesel fueled fleet? Any updates on their experiences, in light of recent petroleum fuel costs?

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Posted by nanaimo73 on Wednesday, March 26, 2008 2:21 AM
It looks like Canadian and Australian producers of hard coking coal are going to see a 300% increase in the price they receive for this year. Perhaps steam coal may begin rising quickly in price.
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Posted by MichaelSol on Wednesday, March 26, 2008 12:05 AM

 wsherrick wrote:
  I know from years of experience and by empirical observation of the locomotives I have operated about how any given steam locomotive of equal weight to a diesel, blows the diesel away after you get it above 5 MPH or so.  I know that diesels have supposedly more tractive effort at starting than the steam engine with approx the same weight on the drivers, but what you find out when you run the diesels is that they often can't take advantage of this tractive effort because of the power to weight ratio. EMD's are especially bad in this area. The diesel easily slips at starting because there is not simply enough weight on the driving wheels to take advantage of it.  Often times one has to have the engine pull against the independent brake, peg the Amperes way up into the danger zone and get the train started that way because otherwise the diesel simply can't start the train without excessive slipping or if it gets started can not maintain the pull necessary to keep the train rolling because the tractive effort and horsepower curves drop off so quickly. So often times it takes two engines to pull what is in the theoretical ability of one engine.  The steam engine once it gets the train rolling can generally accelerate it and pull it with ease.

That's interesting. I mis-spoke on my original post, stating that Steam TE surpassed Diesel-electric TE at 11 mph. I was in a hurry on the way out the door this morning, and misread the chart -- as you point out, the threshhold is much lower, and I corrected my original post to show the crossover at 6 mph.

Your observations make sense. Since "they never let me blow the whistle, they never let me ring the bell ..." it is interesting to see how the observations match well with the performance curves. Too, thinking in terms of economic efficiency -- the Diesel-electric tops out at about 11 mph. Everything after that is brute force -- fuel consumed. The Steam engine just starts to get loosened up.

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Posted by Murphy Siding on Tuesday, March 25, 2008 10:23 PM
 tattooguy67 wrote:
 carnej1 wrote:

 rrandb wrote:
The fact that most electricity is produced by coal and not diesel tells which is most cost effective period.

 Cost effectiveness varies by application. After all coal fired automobiles would have much cheaper fuel costs than the ones we all drive but is anyone going to argue that the Stanley Steamer is going to make a comeback?....

What are you talking about here?, i just had them over yesterday to clean my carpets, they did not go out of business, you need to check your facts better carnej1.
Laugh [(-D] OK, that was funny.Thumbs Up [tup]

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Posted by CNW 6000 on Tuesday, March 25, 2008 8:58 PM
 MichaelSol wrote:

 CNW 6000 wrote:
So after reading that last post the steam loco should be able to out do any diesel.  Were the RRs collectively duped or were they stupid for going diesel?

What you can see from those numbers is why the Diesel-electric made such a good switch engine compared to Steam. But out on the road, where presumably a big engine spent most of its time, Steam showed its muscle if somebody really wanted the train to move...

I suppose if someone enjoys ironies, above 11 mph, the Steam engine outclassed the Diesel-electric in Tractive Effort, and above 19 mph, in all respects; the irony is that the vast bulk of Diesel-electrics road engines, with DC traction motors, could not operate long below 11 mph without damage.

From Brown:

[Click to enlarge]

Micheal that's an explanation I can actually understand.  Thanks.  However, that comparison relates to DC if I read it correctly.  What about AC traction?

Dan

  • Member since
    June 2007
  • From: Indiana
  • 3,549 posts
Posted by Flashwave on Tuesday, March 25, 2008 7:16 PM

Hiho. Model Railroader here, but this caught my eye. One of my a:87 fantasy ideas is a modern sghortline making a buisness in "classic" lease engines. One department being steam engines, running on a Hydrogen engine instead of a coal fed fire. Hydrogen engine creats some heat on it's own but also feds an electic heater, which makes steam, which goes through pipes, which makes a steam engine work.

Hey, a guy can sdream can't he?

-Morgan

  • Member since
    March 2008
  • 146 posts
Posted by wsherrick on Tuesday, March 25, 2008 7:00 PM
 MichaelSol wrote:

 CNW 6000 wrote:
So after reading that last post the steam loco should be able to out do any diesel.  Were the RRs collectively duped or were they stupid for going diesel?

What you can see from those numbers is why the Diesel-electric made such a good switch engine compared to Steam. But out on the road, where presumably a big engine spent most of its time, Steam showed its muscle if somebody really wanted the train to move...

I suppose if someone enjoys ironies, above 11 mph, the Steam engine outclassed the Diesel-electric in Tractive Effort, and above 19 mph, in all respects; the irony is that the vast bulk of Diesel-electrics road engines, with DC traction motors, could not operate long below 11 mph without damage.

From Brown:

[Click to enlarge]

Thanks for all of your effort to post these graphs and other statistics.  I know from years of experience and by empirical observation of the locomotives I have operated about how any given steam locomotive of equal weight to a diesel, blows the diesel away after you get it above 5 MPH or so.  I know that diesels have supposedly more tractive effort at starting than the steam engine with approx the same weight on the drivers, but what you find out when you run the diesels is that they often can't take advantage of this tractive effort because of the power to weight ratio. EMD's are especially bad in this area. The diesel easily slips at starting because there is not simply enough weight on the driving wheels to take advantage of it.  Often times one has to have the engine pull against the independent brake, peg the Amperes way up into the danger zone and get the train started that way because otherwise the diesel simply can't start the train without excessive slipping or if it gets started can not maintain the pull necessary to keep the train rolling because the tractive effort and horsepower curves drop off so quickly. So often times it takes two engines to pull what is in the theoretical ability of one engine.  The steam engine once it gets the train rolling can generally accelerate it and pull it with ease.

  • Member since
    October 2004
  • 3,190 posts
Posted by MichaelSol on Tuesday, March 25, 2008 5:12 PM

 CNW 6000 wrote:
So after reading that last post the steam loco should be able to out do any diesel.  Were the RRs collectively duped or were they stupid for going diesel?

What you can see from those numbers is why the Diesel-electric made such a good switch engine compared to Steam. But out on the road, where presumably a big engine spent most of its time, Steam showed its muscle if somebody really wanted the train to move...

I suppose if someone enjoys ironies, above 6 mph, the Steam engine outclassed the Diesel-electric in Tractive Effort, and above 19 mph, in all respects; the irony is that the bulk of Diesel-electric road engines, with DC traction motors, could not operate long below 11 mph without damage from overheating of the traction motors. So, by necessity the Diesel-electric road engine operated in the area of the curve where Steam had the superior performance characteristics. And that is suggestive that the decision to Dieselize was almost entirely an economic decision based on the price of fuel at the ultimate sacrifice of certain operating advantages of steam locomotion. Well, that's an interesting theory ...

From Brown:

[Click to enlarge]

  • Member since
    December 2005
  • From: MP 175.1 CN Neenah Sub
  • 4,917 posts
Posted by CNW 6000 on Tuesday, March 25, 2008 12:45 PM
 tattooguy67 wrote:
 carnej1 wrote:

 rrandb wrote:
The fact that most electricity is produced by coal and not diesel tells which is most cost effective period.

 Cost effectiveness varies by application. After all coal fired automobiles would have much cheaper fuel costs than the ones we all drive but is anyone going to argue that the Stanley Steamer is going to make a comeback?....

What are you talking about here?, i just had them over yesterday to clean my carpets, they did not go out of business, you need to check your facts better carnej1.

He was referring to this I think.

Dan

  • Member since
    August 2007
  • From: Kalamazoo, MI
  • 323 posts
Posted by tattooguy67 on Tuesday, March 25, 2008 12:16 PM
 carnej1 wrote:

 rrandb wrote:
The fact that most electricity is produced by coal and not diesel tells which is most cost effective period.

 Cost effectiveness varies by application. After all coal fired automobiles would have much cheaper fuel costs than the ones we all drive but is anyone going to argue that the Stanley Steamer is going to make a comeback?....

What are you talking about here?, i just had them over yesterday to clean my carpets, they did not go out of business, you need to check your facts better carnej1.
Is it time to run the tiny trains yet george?! is it huh huh is it?!

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