MichaelSol wrote: The "power characteristics" are considerably different. As a given train tonnage attempts to increase in speed, the Davis Formula shows that increasing horsepower is required to keep moving the train. The Diesel-electric puts out a pretty good hp at low speeds -- where it isn't required. It "craps out" at the higher speeds because its ability to continue to develop horsepower is remarkably limited. The reciprocating steam engine continues to develop horsepower at higher speeds -- exactly where the train needs higher horsepower! For locomotives with comparable weight on the drivers, a given set of train and tonnage conditions, they would compare as follows:MPH Diesel-electric Steam HP needed5 4,2781,806 30710 5,1333,613 74315 5,6004,516 1,23920 5,6005,600 1,83925 5,6006,323 2,56230 5,6007,226 3,42635 5,6007,677 4,44640 5,6007,948 5,64145 5,6008,129 7,02850 5,6008,310 8,62455 5,6008,400 10,44760 5,6008,310 12,51365 5,6008,219 14,84070 5,6008,129 17,445As this shows, the Steam engine doesn't put out nearly the hp at 5 mph, but it also doesn't need much. It has plenty of power to move the train. Above 20 mph the Steam engine has more hp available for acceleration than the Diesel-electric. At about 40 mph, the Diesel-electric poops out, and doesn't have enough power to continue to move the train, but the Steam engine continues to develop the horsepower necessary to keep the train moving and continues to do so to nearly 50 mph. At 70 mph, two Steam engines are able to provide the work that requires three Diesel-electrics. It does this at approximately 40% of the capital cost of the Diesel-electric, and, now, at approximately 20% of the operating cost.
The "power characteristics" are considerably different. As a given train tonnage attempts to increase in speed, the Davis Formula shows that increasing horsepower is required to keep moving the train. The Diesel-electric puts out a pretty good hp at low speeds -- where it isn't required. It "craps out" at the higher speeds because its ability to continue to develop horsepower is remarkably limited. The reciprocating steam engine continues to develop horsepower at higher speeds -- exactly where the train needs higher horsepower! For locomotives with comparable weight on the drivers, a given set of train and tonnage conditions, they would compare as follows:
As this shows, the Steam engine doesn't put out nearly the hp at 5 mph, but it also doesn't need much. It has plenty of power to move the train. Above 20 mph the Steam engine has more hp available for acceleration than the Diesel-electric. At about 40 mph, the Diesel-electric poops out, and doesn't have enough power to continue to move the train, but the Steam engine continues to develop the horsepower necessary to keep the train moving and continues to do so to nearly 50 mph. At 70 mph, two Steam engines are able to provide the work that requires three Diesel-electrics.
It does this at approximately 40% of the capital cost of the Diesel-electric, and, now, at approximately 20% of the operating cost.
Thanks for posting this information. In looking over this table, I have some comments and questions. I don't know that I would interpret this as showing the diesel crapping out at higher speeds, or rather, a confirmation that the diesel can deliver nearly its full horsepower at very low speeds whereas steamers cannot. Actually I do not understand why the diesel cannot deliver its 5600 hp at 10 and 5 mph as well as all other speeds. I am guessing that the answer to that question might be a limitation in traction motors.
Also, it appears to me that the comparison is between a 5600 hp diesel locomotive and an 8400 hp (or higher) steam locomotive, which furthers the suggestion that the diesel stalls out on producing more horsepower needed for higher speeds.
I do not understand why the horsepower of the steamer falls off as its train speed increases from 55 to 70 mph. I thought that any time the speed is increased, more horsepower is required to do so.
What does the last column of figures on the right indicate?
As for what type of steamer, the UP Challenger and the N&W A are good examples to use. Without modern redesign these engines still could give any new diesel a good run for its money on a one to one basis, and in the case of the A it was shown it was more costly to convert to diesel, with more units being required to replace the A in its specific service.
When the American Freedom Train was operating on the Southern Railway's Atlanta - Washington main, SOU decided to include one of their research cars to test the drawbar capability of the Espee 4-8-4. The tests showed that, while pulling a considerably longer AFT (compared to consists of the Southern Crescent) the steamer purformed the work of 2½ the work of E8As. While I don't have the copy of Trains magazine that talked about it maybe someone can fill in more about the tests.
Back in the day EMD F7s couldn't outpull an N&W Y6b with equivalent consists, and that has been well documented as well, and that with both competitors cheating!!! EMD installed 1750 HP engines in all four units, N&W added steam lines to the low power cylinders to help heat-up the used steam going to them, and the Y6b outpulled the Fs. This adaption of the Y6b was applied to many of the engines that lasted until the end of steam, making for a slightly more powerful engine overall. (These tests also being covered extensively in Trains magazine.)
During the 80s when the N&W J and A were being used on excursions all over the Norfolk Southern system I saw with my own eyes excursion trains of over 20 cars long handled by these steamers by themselves on the Salsibury - Asheville mainline traveling at a healthy pace, and yet when diesels had to substitute it was usually three engines running at the same speed. All things considered the science that is being applied to the idea of diesel-electric vs steam locomotives and their pulling abilities favor the steamer, and operations on the prototype bear these same factors out as being true.
As this shows, the Steam engine doesn't put out nearly the hp at 5 mph, but it also doesn't need much. It has plenty of power to move the train. It has six times the amount of horsepower necessary to move the train. Above 20 mph the Steam engine has more hp available for acceleration than the Diesel-electric. At about 40 mph, the Diesel-electric poops out, and doesn't have enough power to continue to move the train, but the Steam engine continues to develop the horsepower necessary to keep the train moving and continues to do so to nearly 50 mph. At 70 mph, two Steam engines are able to provide the work that requires three Diesel-electrics.
Bucyrus wrote: If a steam locomotive and a diesel locomotive each producing say 4000 hp and pulling enough tonnage in identical trains on identical track to limit the top speed to say 40 mph; the tonnage of the two trains would be identical. Is that not true?
If a steam locomotive and a diesel locomotive each producing say 4000 hp and pulling enough tonnage in identical trains on identical track to limit the top speed to say 40 mph; the tonnage of the two trains would be identical. Is that not true?
His statement is meaningless in this context because all he is actually saying is that two machines putting out the same horsepower can pull the same tonnage. Well, that pretty much means that we have the relationship between horsepower and work figured out, but the statement has nothing to do with steam vs diesel power characteristics.
MichaelSol wrote: AnthonyV wrote: Based on the inherent power characteristics of each type of locomotive, the Diesel should always pull at least as much tonnage as a steam engine over the entire practical speed range for a given maximum dbhp.Anthony V.This is exactly the opposite of what is clearly shown by the published and generally accepted TE/HP curves for the respective motive power types. And those do, in fact, define the "inherent power characteristics."
AnthonyV wrote: Based on the inherent power characteristics of each type of locomotive, the Diesel should always pull at least as much tonnage as a steam engine over the entire practical speed range for a given maximum dbhp.Anthony V.
Based on the inherent power characteristics of each type of locomotive, the Diesel should always pull at least as much tonnage as a steam engine over the entire practical speed range for a given maximum dbhp.
Anthony V.
This is exactly the opposite of what is clearly shown by the published and generally accepted TE/HP curves for the respective motive power types. And those do, in fact, define the "inherent power characteristics."
Michael,
If I may parse Anthony's statement, the following conclusion could be drawn from it, according to my interpretation of it:
When you say that the truth is opposite of what Anthony said, I am not sure what you mean by opposite.
GP40-2 wrote: AnthonyV wrote:If the AC6000 does in fact produce 5600 dbhp at 70 mph, wouldn't it pull the same tonnage as a steam engine that produces 5600 dbhp at that speed? Anthony V.Of course it would. But remember, this is Trains.com and very few here want to hear about physics and actual railroading. It gets in the way of fantasy.Case in point:jmlaboda...I'll guarenty you its far less than you would think...The facts are already proven and are undisputeable (irregardless of whether a person cares to believe them or not)...Unlike a diesel-electric, whose ability to haul "X" amount of tonage decreases as they go faster steamers don't have that problem.The last comment is the best one. The writer actually claims that steam locomotives, which have a maximum HP constraint just like diesels, are somehow immune to the laws of physics at high speed LOL.
AnthonyV wrote:If the AC6000 does in fact produce 5600 dbhp at 70 mph, wouldn't it pull the same tonnage as a steam engine that produces 5600 dbhp at that speed? Anthony V.
I have been following this point about comparing steamers to diesels in regard to power falling off at speed, particularly the comparison of the AC6000 to a steam locomotive. However, it is not clear to me exactly what steamer we are comparing the AC6000 to, or what the comparing performance graphs are expected to show.
Here is my take on it. With both types of locomotives, the faster you pull a load, the more horsepower is required. When examples are cited of using multiple diesels on a train that would require one steam locomotive, the reason is that the steamer has more horsepower than the individual diesel units. As has been stated, a diesel delivering 5600 hp at 70 mph will pull the same train as a steamer delivering 5600 hp at 70 mph.
If there is a fundamental difference in the ability of the two locomotive types to deliver horsepower at comparable speeds, it is that steamers are unable to develop full horsepower until they reach a certain speed, whereas diesels can develop full horsepower from a standing start, all the way up to full speed. At starting or moving at lower speeds, they may not have enough adhesion to deliver that full horsepower without wheel slip, but nevertheless, the full horsepower can be developed if the engine is at maximum RPM. Likewise, a steamer develops its maximum horsepower at its maximum RPM, but it needs to be moving at its maximum speed to be turning its maximum RPM.
Still waiting on that AC6000 horsepower curve there jeepee.
The steam advocates provided theirs, now you provide yours.
selector wrote:wsherrick, please check your pm's.
Thank you for sending the note, I appreciate it very much.
AnthonyV wrote:If the AC6000 does in fact produce 5600 dbhp at 70 mph, wouldn't it pull the same tonnage as a steam engine that produces 5600 dbhp at that speed?Anthony V.
jmlaboda wrote: I have been casually following excerts from this thread on the N&W mailing list and have decided to jump into the fray... GP40-2 wrote:Obviously, you have never operated an AC6000 at speed. For the record, CSX's AC6000s develop over 5600 HP at the drawbar at 70-75MPH, so if you want to call that "crapping out" I guess you are entitled to your opinion.Yah, I would like to see that curve as well, or better still, just how many cars a single AC6000 could pull at 70-75MPH. I'll guarenty you its far less than you would think.The facts are already proven and are undisputeable (irregardless of whether a person cares to believe them or not)... ton for ton a steam locomotive can and does pull more tons at higher speeds than a diesel locomotive can.Unlike a diesel-electric, whose ability to haul "X" amount of tonage decreases as they go faster steamers don't have that problem. The traction curve graph merely shows what was proven time and time again in a variety of ways and in a variety of enviroments on railroads using dynomometer cars. On curvy right-of-way and on lines with heavy grades, diesels loose their ability to keep a train going at higher speeds, except that they pile on more diesels. The H.P. of a diesel is less effective at faster speeds because more electricity is needed to keep the traction motors spinning at the higher speeds. This is why there are many a photo of trains from out west that have five, six and seven locomotives on the point, so that they can maintain the higher speeds.Back when the American Freedom Train was operating through the southeast Southern Railway ran some tests on the Southern Pacific GS4 4-8-4. Those tests, which were conducted in one of Southern's research cars (which were able to act as dynomometer cars as well as testing the track) showed that at passenger speeds the GS4 operated at the equivalent of 2½ EMD E8As... 5625 H.P. at track speeds on the Atlanta - Washington mainline.Back when there was a lot of hipe (but little action) on the American Coal Enterprises 4-8-4 3000, a diesel cowled body on a 3000 HP steam locomotive frame and tender, the unit was predicted to be able to replace a GP40 one-to-one. The bad part was, despite efforts to garner support for such, aside from some promotional tours using restored steam locomotives there was little actually done to get the steamer built. If the technology of that time had been put forward to something like a 2-6-6-4, it is difficult to say just how powerful the steamer (or would it be a "unit") would have been. The following url will tell you more about what was purposed... http://www.trainweb.org/tusp/ult.htmlProbably the biggest drawback to the idea of modern day steam would be the fact that except really big money were to be put behind such a project it likely would never even get beyond the planning stage, largely because of diesel's dominance in the field. And then you would have to look at the idea of emissions, which would really hit any coal-fired locomotive hard. But advancements there in the industrial fields likely would lessen the enviromental impact. Building modern steam. Its well within reason and lines that haul amounts of coal ought to look at it. Whether the "so-called" visionaries that lead the various Class Ones can see beyond their really big pay check is hard to say, but maybe it could happen... just maybe...
I have been casually following excerts from this thread on the N&W mailing list and have decided to jump into the fray...
GP40-2 wrote:Obviously, you have never operated an AC6000 at speed. For the record, CSX's AC6000s develop over 5600 HP at the drawbar at 70-75MPH, so if you want to call that "crapping out" I guess you are entitled to your opinion.
Yah, I would like to see that curve as well, or better still, just how many cars a single AC6000 could pull at 70-75MPH. I'll guarenty you its far less than you would think.
The facts are already proven and are undisputeable (irregardless of whether a person cares to believe them or not)... ton for ton a steam locomotive can and does pull more tons at higher speeds than a diesel locomotive can.
Unlike a diesel-electric, whose ability to haul "X" amount of tonage decreases as they go faster steamers don't have that problem. The traction curve graph merely shows what was proven time and time again in a variety of ways and in a variety of enviroments on railroads using dynomometer cars. On curvy right-of-way and on lines with heavy grades, diesels loose their ability to keep a train going at higher speeds, except that they pile on more diesels. The H.P. of a diesel is less effective at faster speeds because more electricity is needed to keep the traction motors spinning at the higher speeds. This is why there are many a photo of trains from out west that have five, six and seven locomotives on the point, so that they can maintain the higher speeds.
Back when the American Freedom Train was operating through the southeast Southern Railway ran some tests on the Southern Pacific GS4 4-8-4. Those tests, which were conducted in one of Southern's research cars (which were able to act as dynomometer cars as well as testing the track) showed that at passenger speeds the GS4 operated at the equivalent of 2½ EMD E8As... 5625 H.P. at track speeds on the Atlanta - Washington mainline.
Back when there was a lot of hipe (but little action) on the American Coal Enterprises 4-8-4 3000, a diesel cowled body on a 3000 HP steam locomotive frame and tender, the unit was predicted to be able to replace a GP40 one-to-one. The bad part was, despite efforts to garner support for such, aside from some promotional tours using restored steam locomotives there was little actually done to get the steamer built. If the technology of that time had been put forward to something like a 2-6-6-4, it is difficult to say just how powerful the steamer (or would it be a "unit") would have been. The following url will tell you more about what was purposed... http://www.trainweb.org/tusp/ult.html
Probably the biggest drawback to the idea of modern day steam would be the fact that except really big money were to be put behind such a project it likely would never even get beyond the planning stage, largely because of diesel's dominance in the field. And then you would have to look at the idea of emissions, which would really hit any coal-fired locomotive hard. But advancements there in the industrial fields likely would lessen the enviromental impact.
Building modern steam. Its well within reason and lines that haul amounts of coal ought to look at it. Whether the "so-called" visionaries that lead the various Class Ones can see beyond their really big pay check is hard to say, but maybe it could happen... just maybe...
If the AC6000 does in fact produce 5600 dbhp at 70 mph, wouldn't it pull the same tonnage as a steam engine that produces 5600 dbhp at that speed?
wsherrick wrote: GP40-2 wrote: Norman Saxon wrote:l'll break this down for you in the simplest terms possible. Here's the reason that coal burned in a modern external combustion engine results would result in cleaner emissions than diesel fuel being burned in a modern compression-ignition engine: The fire in the external combustion engine is constant, while the fire in the compression-ignition engine is instantaneous. Not every bit of volatile material can combust in that brief instant, so we have to either try to reburn it or clean the exhaust post combustion before it is emitted from the tailpipe. But with the external combution engine's constant fire, every bit of volatile material can burn with proper draft sequence as explained by Mr. Sol and Wsherrick.Now do you understand? By that same token, it is likely a modern reciprocating steam engine that used diesel fuel would burn cleaner than a modern diesel-electric. In other words, it's the method of combustion that is key, not necessarily the fuel source.Oh, and that Honda i-DTEC? Certainly cleaner than current diesel engine offerings,firebox design before he improved it. but still dirtier than a modern external combustion chamber. Nice try though.The only way to really clean a compression-ignition engine is to rid the fuel of aromatics before combustion, and the only way to do that is via FT synthesis. And since coal is cheaper than petroleum by a long shot, if you're going to use the FT process, you're going to use coal unless you're a fatalist.I'll break this down for you in the simplest terms possible:The amount of pollution any engine makes is DIRECTLY PROPORTIONAL to the amount of fuel it burns. Even assuming that all the changes you guys propose making to "modern" steam, (which only has anecdotal evidence of working on an actual locomotive) the steam locomotive still has to burn over 4 times the amount of fuel to generate the same power as a modern turbo-diesel. Throw in compound turbocharging, and it goes past 5 times the amount of fuel for a given HP output. You also completely ignored the fact that fluid bed combustion of coal INCREASES the CO2 output (the politicians will love you for that when they pass carbon taxes), mercury, and PAH's.Nice try though with your short sighted explanation.No, the Gas Producing Firebox has been installed on several locomotives and built new in a batch of 10 Mitsubishi 2-10-2's designed by Dante Porta. These locomotives had the first design of firebox before it was improved later.The specs for these engines are amazing and show just how much more potiential exists in a steam locomotive.Here they are:Gauge of track: 2'51/2" (pretty narrow)Engine weight: 48 tons (pretty light)firebox grate area: 22.5 sq. ft. (pretty small)fuel : Sub Bituminous Coal (lignite) BTU per pound: 10,000 Ash content per pound:14%(pretty crappy coal) Coal consumption per drawbar horsepower/per hour: 2.2 lbs. (not very much)1,341 drawbar horsepower (astounding for an engine weighing only 48 tons on a 2 ft gauge railroad)Tonnage rating: 1,500-2000 tons @ 50 MPH. (A whole lot of tons for a 48 ton engine burning 2 pounds of coal per horsepower per hour.)Summery: pulls a whole lot of train, pretty fast with terrible coal for a tiny cost. Just multiply those figures to fit an engine the size of the Challenger.So I guess that firebox would work pretty well in theory.
GP40-2 wrote: Norman Saxon wrote:l'll break this down for you in the simplest terms possible. Here's the reason that coal burned in a modern external combustion engine results would result in cleaner emissions than diesel fuel being burned in a modern compression-ignition engine: The fire in the external combustion engine is constant, while the fire in the compression-ignition engine is instantaneous. Not every bit of volatile material can combust in that brief instant, so we have to either try to reburn it or clean the exhaust post combustion before it is emitted from the tailpipe. But with the external combution engine's constant fire, every bit of volatile material can burn with proper draft sequence as explained by Mr. Sol and Wsherrick.Now do you understand? By that same token, it is likely a modern reciprocating steam engine that used diesel fuel would burn cleaner than a modern diesel-electric. In other words, it's the method of combustion that is key, not necessarily the fuel source.Oh, and that Honda i-DTEC? Certainly cleaner than current diesel engine offerings,firebox design before he improved it. but still dirtier than a modern external combustion chamber. Nice try though.The only way to really clean a compression-ignition engine is to rid the fuel of aromatics before combustion, and the only way to do that is via FT synthesis. And since coal is cheaper than petroleum by a long shot, if you're going to use the FT process, you're going to use coal unless you're a fatalist.I'll break this down for you in the simplest terms possible:The amount of pollution any engine makes is DIRECTLY PROPORTIONAL to the amount of fuel it burns. Even assuming that all the changes you guys propose making to "modern" steam, (which only has anecdotal evidence of working on an actual locomotive) the steam locomotive still has to burn over 4 times the amount of fuel to generate the same power as a modern turbo-diesel. Throw in compound turbocharging, and it goes past 5 times the amount of fuel for a given HP output. You also completely ignored the fact that fluid bed combustion of coal INCREASES the CO2 output (the politicians will love you for that when they pass carbon taxes), mercury, and PAH's.Nice try though with your short sighted explanation.
Norman Saxon wrote:l'll break this down for you in the simplest terms possible. Here's the reason that coal burned in a modern external combustion engine results would result in cleaner emissions than diesel fuel being burned in a modern compression-ignition engine: The fire in the external combustion engine is constant, while the fire in the compression-ignition engine is instantaneous. Not every bit of volatile material can combust in that brief instant, so we have to either try to reburn it or clean the exhaust post combustion before it is emitted from the tailpipe. But with the external combution engine's constant fire, every bit of volatile material can burn with proper draft sequence as explained by Mr. Sol and Wsherrick.Now do you understand? By that same token, it is likely a modern reciprocating steam engine that used diesel fuel would burn cleaner than a modern diesel-electric. In other words, it's the method of combustion that is key, not necessarily the fuel source.Oh, and that Honda i-DTEC? Certainly cleaner than current diesel engine offerings,firebox design before he improved it. but still dirtier than a modern external combustion chamber. Nice try though.The only way to really clean a compression-ignition engine is to rid the fuel of aromatics before combustion, and the only way to do that is via FT synthesis. And since coal is cheaper than petroleum by a long shot, if you're going to use the FT process, you're going to use coal unless you're a fatalist.
Here's the reason that coal burned in a modern external combustion engine results would result in cleaner emissions than diesel fuel being burned in a modern compression-ignition engine: The fire in the external combustion engine is constant, while the fire in the compression-ignition engine is instantaneous. Not every bit of volatile material can combust in that brief instant, so we have to either try to reburn it or clean the exhaust post combustion before it is emitted from the tailpipe. But with the external combution engine's constant fire, every bit of volatile material can burn with proper draft sequence as explained by Mr. Sol and Wsherrick.
Now do you understand? By that same token, it is likely a modern reciprocating steam engine that used diesel fuel would burn cleaner than a modern diesel-electric. In other words, it's the method of combustion that is key, not necessarily the fuel source.
Oh, and that Honda i-DTEC? Certainly cleaner than current diesel engine offerings,firebox design before he improved it. but still dirtier than a modern external combustion chamber. Nice try though.
The only way to really clean a compression-ignition engine is to rid the fuel of aromatics before combustion, and the only way to do that is via FT synthesis. And since coal is cheaper than petroleum by a long shot, if you're going to use the FT process, you're going to use coal unless you're a fatalist.
No, the Gas Producing Firebox has been installed on several locomotives and built new in a batch of 10 Mitsubishi 2-10-2's designed by Dante Porta. These locomotives had the first design of firebox before it was improved later.
The specs for these engines are amazing and show just how much more potiential exists in a steam locomotive.
Here they are:
Gauge of track: 2'51/2" (pretty narrow)
Engine weight: 48 tons (pretty light)
firebox grate area: 22.5 sq. ft. (pretty small)
fuel : Sub Bituminous Coal (lignite) BTU per pound: 10,000 Ash content per pound:14%
(pretty crappy coal)
Coal consumption per drawbar horsepower/per hour: 2.2 lbs. (not very much)
1,341 drawbar horsepower (astounding for an engine weighing only 48 tons on a 2 ft gauge railroad)
Tonnage rating: 1,500-2000 tons @ 50 MPH. (A whole lot of tons for a 48 ton engine burning 2 pounds of coal per horsepower per hour.)
Summery: pulls a whole lot of train, pretty fast with terrible coal for a tiny cost. Just multiply those figures to fit an engine the size of the Challenger.
So I guess that firebox would work pretty well in theory.
I brought this up from a few pages back in the thread to give some context to Whole Elephant's question about the A Class. If you look at the performance ratings of this little narrow gauge engine, it is plain that similar design characteristics brought up to speed in a locomotive the size of an A Class, then 10,000 horsepower in a single unit is not the seemingly rash statement it appears to be.
If this little 48 ton locomotive can haul 2000 ton coal trains at 50 MPH on a poorly laid 2 foot gauge track, burning lignite coal at a rate of 2 pounds per horsepower per hour to produce this performance, then imagine what could be achieved with a 300 ton locomotive on standard gauge track with any high BTU fuel be it coal or whatever.
wsherrick wrote: wholelephant wrote: Maybe this will settle somthing.Let's see what 1218 can do with a 7500 ton train on straight, level track, maybe even where the Class A's regularly hauled such trains 60 mph or so.And let's see what three SD70s can do with such a train. My guess is they will not quite make it to 60 mph.And of course we keep close track of the fuel and water consumption.Let's see what is more economical by today's prices to run heavy trains at such speed.The capital costs are more speculative. The prices of diesels are well known, but what it would cost to produce steam locomotives in any quantity is speculative indeed. And if we did produce new steam, it would be with the Porta/Wardale boiler, Lempor exhaust, poppet valves, and 300 lb pressure. How much these would be worth is speculative too, but some reaonable estimate should not be beyond reach. It is speculative too how much interest rates will rise, but not especially speculative they will rise considerably in the reasonably near future. Higher interest rates will greatly favor the lower capital costs of steam. Not only that, but they will put a premium on train speed, not unlike on the old Great Northern silk trains. This would be a steam/diesel comparison at the speeds that matter now. And it is not that diesels cannot haul heavy trains fast. It is that they are very expensive in such service, at least by data from twenty years ago. So let's let 1218 strut her stuff. Even her seven decade old technology might be more economical in such service than the latest diesels. When it comes to performance the A Class settled the argument long ago. It pulled more for less money than the diesels that replaced it. A modernized version of the A would have probably near 10,000 horsepower a better factor of adhesion and burn 25 to 40% less fuel and consume a whole lot less water to do what it did back then. There would be no internal combustion machine that could match it, period.
wholelephant wrote: Maybe this will settle somthing.Let's see what 1218 can do with a 7500 ton train on straight, level track, maybe even where the Class A's regularly hauled such trains 60 mph or so.And let's see what three SD70s can do with such a train. My guess is they will not quite make it to 60 mph.And of course we keep close track of the fuel and water consumption.Let's see what is more economical by today's prices to run heavy trains at such speed.The capital costs are more speculative. The prices of diesels are well known, but what it would cost to produce steam locomotives in any quantity is speculative indeed. And if we did produce new steam, it would be with the Porta/Wardale boiler, Lempor exhaust, poppet valves, and 300 lb pressure. How much these would be worth is speculative too, but some reaonable estimate should not be beyond reach. It is speculative too how much interest rates will rise, but not especially speculative they will rise considerably in the reasonably near future. Higher interest rates will greatly favor the lower capital costs of steam. Not only that, but they will put a premium on train speed, not unlike on the old Great Northern silk trains. This would be a steam/diesel comparison at the speeds that matter now. And it is not that diesels cannot haul heavy trains fast. It is that they are very expensive in such service, at least by data from twenty years ago. So let's let 1218 strut her stuff. Even her seven decade old technology might be more economical in such service than the latest diesels.
Maybe this will settle somthing.
Let's see what 1218 can do with a 7500 ton train on straight, level track, maybe even where the Class A's regularly hauled such trains 60 mph or so.
And let's see what three SD70s can do with such a train. My guess is they will not quite make it to 60 mph.
And of course we keep close track of the fuel and water consumption.
Let's see what is more economical by today's prices to run heavy trains at such speed.
The capital costs are more speculative. The prices of diesels are well known, but what it would cost to produce steam locomotives in any quantity is speculative indeed.
And if we did produce new steam, it would be with the Porta/Wardale boiler, Lempor exhaust, poppet valves, and 300 lb pressure. How much these would be worth is speculative too, but some reaonable estimate should not be beyond reach.
It is speculative too how much interest rates will rise, but not especially speculative they will rise considerably in the reasonably near future. Higher interest rates will greatly favor the lower capital costs of steam. Not only that, but they will put a premium on train speed, not unlike on the old Great Northern silk trains.
This would be a steam/diesel comparison at the speeds that matter now. And it is not that diesels cannot haul heavy trains fast. It is that they are very expensive in such service, at least by data from twenty years ago.
So let's let 1218 strut her stuff. Even her seven decade old technology might be more economical in such service than the latest diesels.
When it comes to performance the A Class settled the argument long ago. It pulled more for less money than the diesels that replaced it.
A modernized version of the A would have probably near 10,000 horsepower a better factor of adhesion and burn 25 to 40% less fuel and consume a whole lot less water to do what it did back then. There would be no internal combustion machine that could match it, period.
I posted this response on steam_tech@yahoogroups.com and got several listings of relevant patents.
I had earlier posted the test proposal and got a reply that 1218 needs new flues.
Earlier I looked up a message from about a year ago to the effect that existing manufacturing facilities c
could turn out a steam in rather short order.
CSSHEGEWISCH wrote:Question: Since it appears that almost nobody in the United States manufactures really large castings anymore, could a modern steam locomotive be built on a welded frame?
Unless I'm very mistaken the proposed ACE3000 would have used a welded frame...
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
GP40-2 wrote: MichaelSol wrote: As has been noted, above about 20 mph and the Diesel-electric "craps out" For the record, CSX's AC6000s develop over 5600 HP at the drawbar at 70-75MPH, so if you want to call that "crapping out" I guess you are entitled to your opinion.
MichaelSol wrote: As has been noted, above about 20 mph and the Diesel-electric "craps out"
MichaelSol wrote: wsherrick wrote: The neat thing is this steam engine runs cleaner than a diesel, runs cheaper than a diesel and pulls more cars than a diesel thus earning more money than the diesel, while burning the same fuel as a diesel.The significance of Steam is found in those horsepower/TE curves. That significance is found above 11 mph and becomes more significant at the higher speeds. As has been noted, above about 20 mph and the Diesel-electric "craps out" whereas the Steam engine is still developing power. As you have pointed out, ultimately the Steam engine can always move the train faster. On a single track mainline, the difference can be significant in terms of capacity. If the average running speed of trains is 29 mph, for instance, the line will have approximately 35% greater train capacity than at 19 mph. Revenue over cost of operation increases from 2.2% to 23%, without accounting for the lower operating costs of the Steam power.
wsherrick wrote: The neat thing is this steam engine runs cleaner than a diesel, runs cheaper than a diesel and pulls more cars than a diesel thus earning more money than the diesel, while burning the same fuel as a diesel.
The neat thing is this steam engine runs cleaner than a diesel, runs cheaper than a diesel and pulls more cars than a diesel thus earning more money than the diesel, while burning the same fuel as a diesel.
The significance of Steam is found in those horsepower/TE curves. That significance is found above 11 mph and becomes more significant at the higher speeds. As has been noted, above about 20 mph and the Diesel-electric "craps out" whereas the Steam engine is still developing power. As you have pointed out, ultimately the Steam engine can always move the train faster. On a single track mainline, the difference can be significant in terms of capacity. If the average running speed of trains is 29 mph, for instance, the line will have approximately 35% greater train capacity than at 19 mph. Revenue over cost of operation increases from 2.2% to 23%, without accounting for the lower operating costs of the Steam power.
This difference may not have been apparent when the railroads willingly ran their diesel consists at the track's posted speed - just add protection power and get her to the next siding in a timely fashion. The 25 mph average velocity thus far may be more a function of relative congestion - single line running coupled with two way traffic.
Now that railroads are starting to run their trains in a manner more conscience of the fuel price and top speeds are falling in order to save fuel, this difference between diesel and steam power factors may now become more apparent.
This is burning diesel fuel. But the results for coal are similar with a Porta Firebox as has been stated numerous times.
Pretty cool in my estimation.
wsherrick wrote: As far as pollution goes, here is a revealing graph comparing diesel and modern steam exhaust emissions.It's pretty clear which form of power is the cleanest.
As far as pollution goes, here is a revealing graph comparing diesel and modern steam exhaust emissions.
It's pretty clear which form of power is the cleanest.
Is this comparison based on a coal fired steamer?
daveklepper wrote: I wish to apologize for the use of the word "rediculous" in one of my postings. I should always be more respectful to people with different opinions. My MIT education, experience at Electro Motive and the Boston and Maine, should not be an excuse for arrogance, and again I apologize. There may be untried ways of making turbines, gas, steam, or whatever, more efficient over a wider range. Perhaps blades can be feathered as on advance design prop airplanes, or their can be multiple entry and exit ports so that one large turbine can essential operate as one or as two in parallel. Such technology may not only benefit a return of steam, but may make gas turbine locomotives practical.
I wish to apologize for the use of the word "rediculous" in one of my postings. I should always be more respectful to people with different opinions. My MIT education, experience at Electro Motive and the Boston and Maine, should not be an excuse for arrogance, and again I apologize.
There may be untried ways of making turbines, gas, steam, or whatever, more efficient over a wider range. Perhaps blades can be feathered as on advance design prop airplanes, or their can be multiple entry and exit ports so that one large turbine can essential operate as one or as two in parallel. Such technology may not only benefit a return of steam, but may make gas turbine locomotives practical.
IINM there are multi-stage steam turbines that have multiple steam injector ports giving them improved part load performance. I seem to remember reading that there was an experimental (UK?) direct drive steam turbine locomotive that used such a system. A similiar concept would be using a rotary engine design adapted as a steam expansion engine rather than internal combustion which is what T.W Blasingame has proposed......
CopCarSS wrote: MichaelSol wrote: The adjusted cost for coal at 6% conversion efficiency is now less than one-half the cost of diesel fuel at 32% conversion efficiency. The student paper cited earlier concluded as follows: "US Class I railroads burned 4.2 billion gallons of diesel fuel in 2006, costing $8.1 billion. The dollar value of coal that would accomplish the same amount of "work" is only $3.0 billion, according to calculations. This is a cost savings of $5.1 billion in the single year of 2006."He identifies the specific benefit as a $5.1 billion savings. I haven't checked his math.I'm not arguing with the cost difference of coal vs. oil at the moment. What I'm asking is what is the advantage of steam locomotion as a power source? Is there some compelling reason to boil water instead of using coal for gassification for use in a diesel prime mover?
MichaelSol wrote: The adjusted cost for coal at 6% conversion efficiency is now less than one-half the cost of diesel fuel at 32% conversion efficiency. The student paper cited earlier concluded as follows: "US Class I railroads burned 4.2 billion gallons of diesel fuel in 2006, costing $8.1 billion. The dollar value of coal that would accomplish the same amount of "work" is only $3.0 billion, according to calculations. This is a cost savings of $5.1 billion in the single year of 2006."He identifies the specific benefit as a $5.1 billion savings. I haven't checked his math.
The adjusted cost for coal at 6% conversion efficiency is now less than one-half the cost of diesel fuel at 32% conversion efficiency.
The student paper cited earlier concluded as follows: "US Class I railroads burned 4.2 billion gallons of diesel fuel in 2006, costing $8.1 billion. The dollar value of coal that would accomplish the same amount of "work" is only $3.0 billion, according to calculations. This is a cost savings of $5.1 billion in the single year of 2006."
He identifies the specific benefit as a $5.1 billion savings. I haven't checked his math.
I'm not arguing with the cost difference of coal vs. oil at the moment. What I'm asking is what is the advantage of steam locomotion as a power source? Is there some compelling reason to boil water instead of using coal for gassification for use in a diesel prime mover?
I don't know however, I like this kid's idea and if the figures are true as the chart has indicated then the RR's may want to look at this. There are no diesels today that could equal the power of the massive steamers that once ruled the rails.
.....A train on a downgrade is a reality and will produce such energy to slow it no matter which kind of method is being used....even warming, heating....and I suppose melting brake shoes in some cases. At least it sure does produce plenty of arid smoke under severe conditions.
Quentin
Our community is FREE to join. To participate you must either login or register for an account.