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#1 |
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Cannibal
Join Date: Mar 2002
Location: Looting Fafner's Cave
Posts: 17,556
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Freight Trains Get 436 Miles Per Gallon of Fuel?
Link
Quote:
I'm confused.Nearest I can come up with is that they figure it takes x gallons of fuel to make an empty train go 436 miles, and if you add a ton of freight to that empty train, it will take x + 1 gallons of fuel to go that same 436 miles. I guess by that logic, I could say my Ford Taurus can move Mrs. BPSCG 436 miles on half a pint of gasoline. Sounds like deceptive advertising, close to being downright dishonest. |
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Philanthropist (n.) - Someone who spends his own money to advance his version of Utopia. Socialist (n.) - Someone who spends your money to advance his version of Utopia. |
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#2 |
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Gazerbeam's Protege
Join Date: Apr 2006
Location: The Mended Drum
Posts: 5,630
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I keep hearing a figure close to that quoted on an ad here in Virginia/Maryland for CX Freight, or something like that. It's always bothered me. Doesn't seem like it could possibly be right.
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I wish someone would find something I wrote on this board to be sig-worthy, thereby effectively granting me immortality.--Antiquehunter The gods do not deduct from a man's allotted years on earth the time spent eating butterscotch pudding. AMERICA! NUMBER 1 IN PARTICLE PHYSICS SINCE JULY 4TH, 1776!!! --SusanConstant |
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#3 |
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Mostly harmless
Join Date: Jul 2004
Location: Nor Flanden
Posts: 22,066
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#4 |
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Graduate Poster
Join Date: Sep 2001
Location: Oxford, UK
Posts: 1,833
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I can't say for sure (not enough info in the link), but I suspect that what they mean is that X tons of freight are shipped Y miles by train per year, and Z gallons of fuel are used, such that Y / XZ = 436 miles / gallon x ton.
If this is the case, then assuming that fuel use is proportional to both the weight of freight carried, and the distance it moves, this would be a reasonable measure of fuel efficiency. And assuming that the figure for truck shipping is computed the same way, that would be a fair comparison. Dr. Stupid |
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A poke in the eye makes Baby Jesus cry. |
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#5 |
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Critical Thinker
Join Date: Apr 2006
Posts: 271
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#6 |
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Philosopher
Join Date: Apr 2003
Location: 16 miles from 7 lakes
Posts: 8,416
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Each car on a train can weigh more than 100000 lb. A typical trrain (out west, not talking East, here) will haul well over 10 million lb, or over 10000 tons.
That works out to 11 gallons/mile. (100000 lb/car*100 Cars/(2000lb/ton)/(436 ton*miles/gallon) My numbers are just guesses, and could be off by a large factor--probably on the light side, but it's ball-park, since the engines on a train run at optimum RPM, unlike those in your car, or in a truck. So its not as outrageous as you think... |
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"Political correctness is a doctrine,...,which holds forth the proposition that it is entirely possible to pick up a turd by the clean end." "I pointed out that his argument was wrong in every particular, but he rightfully took me to task for attacking only the weak points." Myriad http://forums.randi.org/showthread.php?postid=6853275#post6853275 |
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#7 |
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useless idiot
Join Date: May 2008
Location: New Jersey-You gotta problem wit dat?
Posts: 4,999
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#8 |
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Master Poster
Join Date: Dec 2006
Location: Kadath in the Cold Waste
Posts: 2,822
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Sure, trains are a massively more efficient means of hauling large amounts of freight at low cost. Think about rails, resistance, and how much actual freight can be hauled. Trucks are restricted in size by the need to actually travel on public roads, and turn corners etc. So yes, trains will always get a massive amount more mpg. I suspect canals and shipping are even more efficient.
cj x |
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I'm an Anglican Christian, so I declare my prejudice here. Please take it in to account when reading my posts. "Most people would rather die than think: many do." - Betrand Russell My dull life blogged http://jerome23.wordpress.com |
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#9 |
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Philosopher
Join Date: Jul 2007
Location: Blue Heaven, NC
Posts: 5,516
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__________________
Insert witty phrase or out of context post by another member here. |
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#10 |
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Philosopher
Join Date: Sep 2005
Location: Colorado
Posts: 5,717
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It's probably right, if you are only talking about the payload weight. A diesel tractor/trailer hauls about 20 net tons (plus another 20 in empt weight) at roughly 6 miles per gallon; that's 120 ton-miles/gal. A train has much less air friction and much less rolling friction to fight, and can run the diesels in a better part of their power curve, since they just generate electricity for the traction motors.
And we ignore infrastructure costs. A train is the way to go, if you are moving more than, say, 10 tens, you don't care about acceleration damage (things are packed really well or are oblivious to 3g accelerations), are conveniently loaded and unloaded (or else you get a truck anyway, plus possible handling damages at either end), and you're willing to wait up to two weeks for the goods. Otherwise, it's going to be trucks. No (or at least not many) rail refrigerator cars anymore, either. |
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#11 |
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Graduate Poster
Join Date: Aug 2007
Posts: 1,012
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__________________
Warning. If you don't want to see your treasured "evidence" completely pwned in public, don't show it to the posters at JREF. - Rolfe |
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#12 |
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Penultimate Amazing
Join Date: Jun 2005
Location: way way north of Diddy Wah Diddy
Posts: 11,180
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Like others, I've always assumed it's "ton miles per gallon," which may or may not be deceptive, depending on how you look at it. So a truck that gets seven miles per gallon, if it hauls ten tons, gets 70 ton miles per gallon, etc. I suppose if you are actually shopping for different ways of moving the same freight, it makes some sense, and it does point up the overall efficiency of rail transport, which is real enough, and if we take as our base an ordinary passenger vehicle or pickup truck, the ton miles per gallon will be approximately the actual miles per gallon of the vehicle, so the figure has a natural reference that is easy to picture.
Still, you have to watch out for this kind of calculation. For one thing, it is almost certainly the optimal cargo density that is being measured, and unlikely to apply to lighter cargo or to passengers. And this kind of thinking can be misapplied altogether. You see the same idea in estimates of airline safety, which is usually measured in passenger miles. A jumbo jet on a long route could probably blow up on every tenth flight, and still deliver an impressive enough number of passenger miles to come up with one of those "safer than driving to the airport" statements. |
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"Sir, I have found you an argument; but I am not obliged to find you an understanding.(Samuel Johnson) The gods are less for their love of praise....(Wendell Berry) |
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#13 |
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Muse
Join Date: Dec 2007
Location: Stockholm, Sweden
Posts: 962
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"A lot of those lobbyists genuinely like people. But then, fleas like people too." - Mike Munger. |
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#14 |
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Philosopher
Join Date: Apr 2003
Location: 16 miles from 7 lakes
Posts: 8,416
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"Political correctness is a doctrine,...,which holds forth the proposition that it is entirely possible to pick up a turd by the clean end." "I pointed out that his argument was wrong in every particular, but he rightfully took me to task for attacking only the weak points." Myriad http://forums.randi.org/showthread.php?postid=6853275#post6853275 |
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#15 |
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Gatekeeper of The Left
Join Date: Sep 2007
Location: The Universe 35.2 ms ahead of this one.
Posts: 32,078
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The only more efficient mode of transport is a ship.
Not a deceptive ad whatsoever - literally true that one gallon moves a ton over 400 miles. And this is why the golden age of railroading was not the 1920s, but NOW. |
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#16 |
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Gatekeeper of The Left
Join Date: Sep 2007
Location: The Universe 35.2 ms ahead of this one.
Posts: 32,078
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BTW, 300,000+ pound freight cars are getting to be pretty much normal... And 10,000 foot trains are pretty normal too.
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#17 |
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Penultimate Amazing
Join Date: Aug 2002
Location: Whithin earshot of the North Sea
Posts: 16,600
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True. That is the usual way to calculate fuel costs over a whole transport sector.
It has some caveats. For instance, the mileage between truck transport and rail ditto may not be quite comparable; a train goes straighter trough the landscape, but a truck can go door to door. Hans |
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Don't. Just don't. |
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#18 |
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useless idiot
Join Date: May 2008
Location: New Jersey-You gotta problem wit dat?
Posts: 4,999
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I assume this is why we see a fair number of truck trailers loaded on freight trains coming through my town. Load up the trailer at one end, have a truck drive to the train depot, have the train handle the long haul, then hitch the trailer to a truck at the other end to get it to the final destination without multiple loadings and unloadings of the individual items.
The manpower productivity advantages of trains must also be huge. A few engineers driving a train 24/7 vs. individual truck drivers who can only haul a small fraction of the freight and who are limited by mandatory rest periods.
Originally Posted by Shadron
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#19 |
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Mostly harmless
Join Date: Jul 2004
Location: Nor Flanden
Posts: 22,066
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"You got to use your brain." - McKinley Morganfield "The poor mystic homeopaths feel like petted house-cats thrown at high flood on the breaking ice." - Leon Trotsky |
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#20 |
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Cannibal
Join Date: Mar 2002
Location: Looting Fafner's Cave
Posts: 17,556
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I think you're saying the same thing I was saying - that it takes one more gallon to move a train with a ton of freight on it 400 miles than it takes to move an empty train that same distance.
But how many gallons does it take to move that empty train that 400 miles? A lot more than it takes to move an empty truck. Really, the fair measure is not how many extra gallons of fuel it takes to move only the ton of freight, or how many gallons of fuel it takes to move only the vehicle, be it train or truck, but how many gallons of fuel it takes to move the ton of freight and its carrier. It seems to me that the statistic presented is cherry-picking of a sort. Again, my Ford Taurus could move Mrs. BPSCG from Washington DC to New York City on only half a pint of fuel. It takes considerably more to get the Ford itself there. BTW, Mojo, Mrs. BPSCG weighs about 18-20 pounds.* *On the moon. |
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Philanthropist (n.) - Someone who spends his own money to advance his version of Utopia. Socialist (n.) - Someone who spends your money to advance his version of Utopia. |
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#21 |
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Mostly harmless
Join Date: Jul 2004
Location: Nor Flanden
Posts: 22,066
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I can't afford exotic holidays like that.
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"You got to use your brain." - McKinley Morganfield "The poor mystic homeopaths feel like petted house-cats thrown at high flood on the breaking ice." - Leon Trotsky |
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#22 |
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Orthogonal Vector
Join Date: Jul 2006
Location: Tarrytown, NY
Posts: 26,417
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Not at all. You see that number includes the base effeciency of the train.
If you have a Train with 10,000 tons of freight and it moves 436 miles, you would expect it to use 10,000 gallons of fuel. It is not about calculateing the loss of moving the vehical with out said freight and then with said freight. |
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Sufficiently advanced Woo is indistinguishable from Parody "There shall be no *poofing* in science" Paul C. Anagnostopoulos Force ***** on reasons back" Ben Franklin |
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#23 |
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Penultimate Amazing
Join Date: May 2002
Location: Mountain View, CA
Posts: 11,021
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In 2007, trains moved 1,770,545,245,000 ton-miles of freight. They consumed 4,062,025,082 gallons of fuel. That's fuel to move not just the freight, but the train as well. It includes fuel consumed in train yards, it excludes passenger trains.
That's an average of 435.88, and as explained it includes the fuel expended to move the train itself. cite |
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May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view. May your mountains rise into and above the clouds. - Edward Abbey Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop off like autumn leaves. - John Muir |
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#24 |
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useless idiot
Join Date: May 2008
Location: New Jersey-You gotta problem wit dat?
Posts: 4,999
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On what basis do you claim that the calculation was done that way?
Were I to calculate the gallons per pound of transporting Mrs. BPSCG to Washington, I would figure out how many gallons of fuel would be required and divide by her weight. One would arrive with different numbers depending on whether she is driving alone or with companions, or depending on the vehicle, but regardless the calculation would be the same: (gallons of fuel)/(weight of cargo) |
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#25 |
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Muse
Join Date: Oct 2004
Posts: 832
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I recall from many years ago, an article (I believe in Sci Am) about the energy efficiency of various forms of transport. The metric used was energy / mass / distance. The mass includes the entire weight of the vehicle and it's contents. The results were surprising:
The most effiecient: a man on a bicyle Second: C5A miltary cargo transport jet I have failed to google this up, so my memory may be wrong. IXP |
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"When reason sleeps, monsters are produced" -- Goya, title of etching that is my avatar |
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#26 |
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Cannibal
Join Date: Mar 2002
Location: Looting Fafner's Cave
Posts: 17,556
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Bear with me while I work through some speculative math...
1,770,545,245,000 ton-miles = moving one ton 1,770,545,245,000 miles, or 1,770,545,245,000 tons one mile. If they could move one ton of train plus freight 1,770,545,245,000 miles, then, presumably, they could move one ton of train-only 1,770,545,245,000 miles. Okay, here's where I get the wild-ass numbers. Assume a train = 200 cars + engine. Assume each car weighs 4 tons (a WAG - wild-ass guess) and the engine weighs 20 tons. That means the train weighs 820 tons. So if one gallon of fuel can move one ton 436 miles, one gallon of fuel would move 820 tons 436/820 = .53 miles. So is it fair to say that while the 436 ton-miles per gallon is accurate, it's also fair to say that (assuming my WAG numbers are more or less in the ballpark) that an empty freight train gets what we commonly think of as mileage - about half a mile per gallon, disregarding the freight carried? |
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Philanthropist (n.) - Someone who spends his own money to advance his version of Utopia. Socialist (n.) - Someone who spends your money to advance his version of Utopia. |
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#27 |
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Penultimate Amazing
Join Date: Jun 2003
Posts: 26,175
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Not necessarily: per-weight fuel efficiency while empty may be different than per-weight fuel efficiency when loaded, because many factors involved don't scale linearly with the weight of the train. Air resistance is one (though maybe not a big one). Engine friction is another (possibly considerable). I'm sure there are others. If you've got nothing else to go on, this sort of calculation is not an unreasonable way to get a rough estimate, but it could easily be off, possibly a lot.
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"As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law |
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#28 |
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Homo Skepticalis
Join Date: Aug 2001
Location: Occupying my barstool
Posts: 3,177
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The Texas Transportation Institute's Center for Ports & Waterways published a report in 2007 called A Modal Comparison of Domestic Freight Transportation on the General Public. Similar reports have been published by the EPA, but the data and methodologies had not been updated since the early 90s. This report published new figures using more recent data regarding fuel efficiencies, emissions, and cargo capacities. The chapter on Energy Efficiency explains how these kinds of statistics are derived and what they mean:
http://tti.tamu.edu/documents/TTI-2007-5.pdf This report has been a useful reference for the work I do, so I was already familiar with it. I noticed that shortly after the report was published, those CSX ads started to appear. While the ads are not actually dishonest, spouting the numbers like that with no frame of reference can be confusing to the general public. The agency I work for uses the counterpart numbers for barge transportation in promotional endeavors, but mainly within circles of those would be likely to understand the context. I'm not sure whether I would say to CSX, "Shame on you" or "Well played." Or maybe it should be, "Good luck with that." I laughed when I saw this thread. |
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Save Caribbean Rum! (seriously) |
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#29 |
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Muse
Join Date: Oct 2004
Posts: 738
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#30 |
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Philosopher
Join Date: Apr 2003
Location: 16 miles from 7 lakes
Posts: 8,416
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__________________
"Political correctness is a doctrine,...,which holds forth the proposition that it is entirely possible to pick up a turd by the clean end." "I pointed out that his argument was wrong in every particular, but he rightfully took me to task for attacking only the weak points." Myriad http://forums.randi.org/showthread.php?postid=6853275#post6853275 |
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#31 |
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Muse
Join Date: Oct 2004
Posts: 832
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That depends on how much cargo you carry!
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"When reason sleeps, monsters are produced" -- Goya, title of etching that is my avatar |
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#32 |
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Gatekeeper of The Left
Join Date: Sep 2007
Location: The Universe 35.2 ms ahead of this one.
Posts: 32,078
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That was TOTAL for all tons moved and all gallons consumed.
It includes deadhead miles against the fuel, but obviously no ton-miles accrue with deadheads. Deadheading is common for things like unit coal trains where the cars themselves are specialized. I don't think it includes maintenance of way trains, but those are far less than 1% of all fuel used. I read the Trains magazine monthly, and have been a rail fan since I was a sprout, so I know what I am talking about here... |
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#33 |
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Gatekeeper of The Left
Join Date: Sep 2007
Location: The Universe 35.2 ms ahead of this one.
Posts: 32,078
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Not quite.
Coal trains tend to be unit trains, cars in a string that are never separated unless one needs to be put in the RIP track. Many tank trains are like this too, with the cars piped together so that they can all be drained/filled from on hose connection rather than being spotted for emptying/filling and multiple connections made and broken. Box cars are a getting scarce. The modern equivalent is the container car, an those too are usually in unit trains and often are in 3-4 car sets that share bogies between the sets. Yes, you will see trains still with mixed cargoes, because some customers generate or consume small shipments of as little as a single car, but those are expensive customers to service, and railroads would really rather run only unit trains to intermodal yards or to power plants or steel mills or similar producers and consumers of multi-car shipments of the same thing. What you almost never, ever find is a railroad willing to take LCL freight, that is Less Than Carload. Usually now one will deal with a freight consolidator who will load a trailer or a container with your goods and those of others and then deliver them at the other end. (Think UPS.) |
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#34 |
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Cannibal
Join Date: Mar 2002
Location: Looting Fafner's Cave
Posts: 17,556
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Duplicate post because everything I say is worth reading twice...
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Philanthropist (n.) - Someone who spends his own money to advance his version of Utopia. Socialist (n.) - Someone who spends your money to advance his version of Utopia. |
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#35 |
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Cannibal
Join Date: Mar 2002
Location: Looting Fafner's Cave
Posts: 17,556
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__________________
Philanthropist (n.) - Someone who spends his own money to advance his version of Utopia. Socialist (n.) - Someone who spends your money to advance his version of Utopia. |
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#36 |
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Philosopher
Join Date: Apr 2007
Location: Tranquility Base
Posts: 8,553
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In terms of the general efficiency of rail travel, let me offer for discussion the following passage from the book, How To Make War - A Comprehensive Guide To Modern Warfare, by James F. Dunnigan. In Chapter 23, Logistics, it says the following:
Quote:
I would expect if there's any one group which would be quite familiar with the fuel costs and relative advantages and disadvantages of different transportation systems, it'd be the military, given its reliance on timely and adequate supplies. |
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"We choose to go to the moon in this decade and do the other things not because they are easy, but because they are hard. Because that goal will serve to organize and measure the best of our abilities and skills, because that challenge is one we are willing to accept, one we are unwilling to postpone, and one which we intend to win." |
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#37 |
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Philosopher
Join Date: Apr 2003
Location: 16 miles from 7 lakes
Posts: 8,416
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__________________
"Political correctness is a doctrine,...,which holds forth the proposition that it is entirely possible to pick up a turd by the clean end." "I pointed out that his argument was wrong in every particular, but he rightfully took me to task for attacking only the weak points." Myriad http://forums.randi.org/showthread.php?postid=6853275#post6853275 |
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#38 |
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Gatekeeper of The Left
Join Date: Sep 2007
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#39 |
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Philosopher
Join Date: Apr 2003
Location: 16 miles from 7 lakes
Posts: 8,416
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__________________
"Political correctness is a doctrine,...,which holds forth the proposition that it is entirely possible to pick up a turd by the clean end." "I pointed out that his argument was wrong in every particular, but he rightfully took me to task for attacking only the weak points." Myriad http://forums.randi.org/showthread.php?postid=6853275#post6853275 |
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#40 |
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Muse
Join Date: Mar 2007
Posts: 743
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This seems totally implausible, unless one excludes food requirements on the basis that we should be losing weight anyway.
Doing some basic math: http://www.nutristrategy.com/fitness/cycling.htm Calories burned per hour for a 140 lb rider, 10-11.9 mph: 381. The rider is 0.07 tons, and we'll assume goes 12 miles an hour, giving an efficiency of 454 C/ton-mi. http://www.sfgate.com/cgi-bin/articl...NG3PHRU681.DTL The important bit: According to researchers at the University of Michigan's Center for Sustainable Agriculture, an average of more than 7 calories of fossil fuel is burned up for every calorie of energy we get from our food. This means that in eating my 400-calorie breakfast, I will, in effect, have consumed 2,800 calories of fossil fuel energy. (Some researchers claim the ratio is as high as 10 to 1.) Going with the 7:1 rate, then, the efficiency in terms of fossil fuel is 3178 C/ton-mi. Of course, these are really kilocalories, since we started talking about food. In joules, we're talking about 13.3 MJ/ton-mi. Diesel has an energy content of 36.4 MJ/liter. So our diesel-equivalent efficiency is 0.365 liters/ton-mi. Converting to ton-mi/gal, we get 10.37. Compared to the 436 that trains get, this is no contest (even if I'm off by a factor of 10 or so in my calcs...). - Dr. Trintignant |
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