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BPSCG
12th February 2009, 07:25 AM
Link (http://www.aar.org/Environment/Environment.aspx)
A freight train can move a ton of freight an average of 436 miles on a single gallon of fuel. Thatís close to four times as far as it could move by truck.:confused: 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.

NobbyNobbs
12th February 2009, 07:27 AM
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.

Mojo
12th February 2009, 07:27 AM
I guess by that logic, I could say my Ford Taurus can move Mrs. BPSCG 436 miles on half a pint of gasoline.


What does Mrs. BPSCG weigh?

Stimpson J. Cat
12th February 2009, 07:33 AM
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

kbm99
12th February 2009, 07:35 AM
Link (http://www.aar.org/Environment/Environment.aspx)
:confused: 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 always assumed it was more along the lines of "It takes 1 gallon of fuel to move a fully-loaded train carrying 436 tons of freight 1 mile." - or some value for fuel and tons that works out to 436 "mile-tons" of freight per gallon of fuel.

Still deceptive.

rwguinn
12th February 2009, 07:43 AM
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...

gdnp
12th February 2009, 07:47 AM
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

This has always been the way that I interpreted the statement. Doesn't mean it's right, obviously....

cj.23
12th February 2009, 07:48 AM
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

madurobob
12th February 2009, 07:48 AM
Link (http://www.aar.org/Environment/Environment.aspx)
:confused: 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.
I wondered the same thing when I heard the CSX ad. Best I could figure was they were telling their customers to negotiate MUCH better transit rates since the incremental cost of them moving a ton of freight was amazingly low.

shadron
12th February 2009, 07:53 AM
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.

maxpower1227
12th February 2009, 07:55 AM
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.

...5,000 tons?

bruto
12th February 2009, 08:02 AM
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.

soylent
12th February 2009, 08:08 AM
Sounds like deceptive advertising, close to being downright dishonest.

Not if you're interested in hauling large quantities of junk.

If you're interested in hauling people, look at people*miles/gallon at average occupancy, time taken and convenience instead.

rwguinn
12th February 2009, 08:17 AM
...5,000 tons?
Duh!
I ripped a ball-park figure off the top of my head in a hurry.
That's why we do loads committees, to catch the obvious....
You're right...
So sorry!

BenBurch
12th February 2009, 08:18 AM
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.

BenBurch
12th February 2009, 08:23 AM
BTW, 300,000+ pound freight cars are getting to be pretty much normal... And 10,000 foot trains are pretty normal too.

MRC_Hans
12th February 2009, 08:27 AM
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. StupidTrue. 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

gdnp
12th February 2009, 08:55 AM
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

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.

And we ignore infrastructure costs.
Are infrastructure costs for rail maintenance higher than those for highways?

Mojo
12th February 2009, 09:15 AM
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. 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.


Trains also don't have to deal as much with gradients - the tracks are generally planned to follow contours where possible, or use cuttings/tunnels/viaducts where not.

BPSCG
12th February 2009, 10:18 AM
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.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.

Mojo
12th February 2009, 10:36 AM
I can't afford exotic holidays like that.

ponderingturtle
12th February 2009, 10:40 AM
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.

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.

roger
12th February 2009, 10:43 AM
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 (http://www.factcheck.org/askfactcheck/can_a_freight_train_really_move_a.html)

gdnp
12th February 2009, 10:53 AM
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.

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)

IXP
12th February 2009, 11:01 AM
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

BPSCG
12th February 2009, 11:14 AM
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 (http://www.factcheck.org/askfactcheck/can_a_freight_train_really_move_a.html)
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?

Ziggurat
12th February 2009, 11:25 AM
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?

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.

Psi Baba
12th February 2009, 11:39 AM
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.

Dilb
12th February 2009, 11:45 AM
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?

True, and that's why you shouldn't trade in your car for a 200-car train.

rwguinn
12th February 2009, 11:49 AM
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?
The secret is to never have an empty train.
While, for example, coal cars must be returned to the mine empty, box cars work both ways--so you mix 'em up...generally.

IXP
12th February 2009, 11:53 AM
That depends on how much cargo you carry!

BenBurch
12th February 2009, 11:55 AM
...
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?

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...

BenBurch
12th February 2009, 12:05 PM
The secret is to never have an empty train.
While, for example, coal cars must be returned to the mine empty, box cars work both ways--so you mix 'em up...generally.

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.)

BPSCG
12th February 2009, 12:21 PM
Duplicate post because everything I say is worth reading twice...

BPSCG
12th February 2009, 12:25 PM
True, and that's why you shouldn't trade in your car for a 200-car train.Okay - you wouldn't believe the mistake I was about to make until you stopped me.

Corsair 115
12th February 2009, 01:37 PM
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:

When supply is moved by sea or rail, the fuel required is not a significant factor. To move a ton of material 100 km by train requires 14 ounces of fuel. A large ship uses about half that amount. When material is moved by truck or air, it's a different story. By truck, 1 percent of the weight moved will be consumed as fuel for each 100 km traveled. By air, the cost will range from 2 to 5 percent, depending on the type of aircraft. Large commercial cargo jets are the most efficient. Helicopters are notorious fuel hogs and can consume 10 percent of their cargo weight for each 100 km traveled. Moving supply by animal, including humans, will have the same fuel cost as aircraft because of the food required. A recent innovation is the portable fuel pipeline, quicky laid alongside existing roads. It is twice as efficient as trucks, but is more vulnerable to attack.


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.

rwguinn
12th February 2009, 01:52 PM
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.)
I bow to your expertise.
I tried to figure all that kinda thing out once. That's why I now just build mountans and tunnels and stuff and simply run the trains around:D

BenBurch
12th February 2009, 03:00 PM
I bow to your expertise.
I tried to figure all that kinda thing out once. That's why I now just build mountans and tunnels and stuff and simply run the trains around:D

I am planning a live steam garden railway. :-)

rwguinn
12th February 2009, 03:03 PM
I am planning a live steam garden railway. :-)
Despite the fact that you are obviously a bleedin' heart, wierdo pinko commie Democrat, and pro'ly long-haired, too, I LIKE you...:D:D

Dr. Trintignant
12th February 2009, 04:04 PM
The most effiecient: a man on a bicyle

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/article.cgi?f=/c/a/2006/03/26/ING3PHRU681.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

LarianLeQuella
12th February 2009, 05:03 PM
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

Too bad C-5s are always broken! :D

Q: What does it mean when there are two C-5s on the ramp, and one is up on jacks?

A: They ran out of jacks!

Sorry, a little AF humour there, feel free to ignore me!

roger
12th February 2009, 06:42 PM
Too bad C-5s are always broken! :D

Q: What does it mean when there are two C-5s on the ramp, and one is up on jacks?

A: They ran out of jacks!

Sorry, a little AF humour there, feel free to ignore me!I loved watching those takeoff from the catwalk of the control tower at Dover.

tesscaline
12th February 2009, 07:13 PM
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/article.cgi?f=/c/a/2006/03/26/ING3PHRU681.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. TrintignantNot to mention: Just how many tons of cargo can a single human on a bicycle actually pull? How many cubic feet of cargo room do they have? And how safe is any cargo that they carry?

After all, there's a reason that refrigerators aren't delivered by bike messenger... :)

Lynx2174
13th February 2009, 01:48 AM
I'm pretty sure they mean that it gets a fraction of a mile per gallon, but moves hundreds of tons, from which you can calculate the average amount of distance moved per unit time per unit fuel per unit weight.

It's not deceptive if you say 436 ton-miles per gallon. After all, the train weighs a lot more than a ton. And it is far more efficient than trucking.

rwguinn
13th February 2009, 08:07 AM
Not to mention: Just how many tons of cargo can a single human on a bicycle actually pull? How many cubic feet of cargo room do they have? And how safe is any cargo that they carry?

After all, there's a reason that refrigerators aren't delivered by bike messenger... :)
To be absolutely fair:
What does it take to drill a 15000 foot hole, insert casing, perforate it, pump it to the surface, transport to the refinery, refine to diesel, manufacture the train, engine and generators, and get the diesel into the tank?
(Hmmm-- Gotta do the same thing for the fuel consumed in agriculture, too, don't we? So it is a wash, and the analysis as presented by Dr. Trintignant is valid.)

BenBurch
13th February 2009, 08:43 AM
Despite the fact that you are obviously a bleedin' heart, wierdo pinko commie Democrat, and pro'ly long-haired, too, I LIKE you...:D:D

In spite of the fact that you are obviously drive a gun-rack pick-em-up with "I AM the NRA" bumper stickers and a "Bush/Cheney '04" sticker still on it, I like you too! :D ;)

Molinaro
13th February 2009, 10:15 AM
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

I wonder where a woman on bicycle ranked? :p