[WhoozOn1st]

CSX currently has an ad running in which it claims to be able to move 1 ton of freight 423 miles on 1 gallon of fuel. Now I wasn't exactly a math major, so I'm wondering if anybody knows how they arrived at this figure. I'm aware of ton miles, but would that claim include all phases of running, or just once the train is up to speed, or what? Also, it would seem the claim must be based on a certain rate of fuel consumption, so which type of locomotive(s) pulling how many tons at what speed, etc.?

Get out your slide rules and gimme some help here, folks!

[AmtrakWPK]

Assuming a relatively flat path, how many tons of freight can an SD70MAC pull? If we assume an average throttle position of 6 that's what - 130 gallons per hour? If we figure a speed of 40 mph, that's roughly ten and a half hours. So can an SD70MAC pull 1375 tons? I have no idea.

[Green Maned Lion]

Well lets assume a double stacker car weighs 5 tons on its own, and that the average container weighs 40 tons. So each car weighs 45 tons. So the question is, can an SD70MAC pull 30 cars?

[WhoozOn1st]

The question is not how many cars a locomotive can pull. Sorry, GML. The question is how much fuel does it take to move a given weight a certain distance. I'm guessing the answer - whatever it is - may differ not only by locomotive type, but also by such factors as ruling grade on a route. Mr. Harris?

[WhoozOn1st]

Okay, I finally broke down and asked CSX directly. Talk about jumping through hoops!

Now taking bets. Current line:

Response from CSX - 100-1

Straight answer - Not enough zeroes to 1.

[PRR 60]

The claim on the CSX commerical is accurate and can be supported by operational data reported by CSX on their most recent SEC Form 8K filed 1/22/08.

From the 4th Quarter 2007 report, CSX moved 253 billion revenue ton-miles of goods in the 12 months ending 12/31/07. In that same period CSX operations consumed 569 million gallons of diesel #2 fuel. Taking the net ton-miles and dividing by the fuel consumed (253 billion / 569 million) you get 444 ton-miles per gallon of fuel. Stated another way, one gallon of fuel moved one ton 444 miles. That is pretty close to the 423 mile claim in the ad.

Data reported by other railroads is similar.

[WhoozOn1st]

PRR 60, on Fri, Feb 1, 2008, 01:14 PM, said:

The claim on the CSX commerical is accurate and can be supported by operational data reported by CSX on their most recent SEC Form 8K filed 1/22/08.

From the 4th Quarter 2007 report, CSX moved 253 billion revenue ton-miles of goods in the 12 months ending 12/31/07. In that same period CSX operations consumed 569 million gallons of diesel #2 fuel. Taking the net ton-miles and dividing by the fuel consumed (253 billion / 569 million) you get 444 ton-miles per gallon of fuel. Stated another way, one gallon of fuel moved one ton 444 miles. That is pretty close to the 423 mile claim in the ad.

Data reported by other railroads is similar.

Thank you, PRR 60. While I never really questioned the numbers (not a math kinda guy), I appreciate you providing a sense of how they were arrived at, which was my question.

[Crescent ATN & TCL]

Now how about the same equation for Amtrak vs Airlines and Busses?, barring the NEC of course, kind of difficult to measure gallons of electricity.

[Green Maned Lion]

Let:
N = the number of tons an engine A can pull
X = the number of tons the average carload carries
Y = the weight of Z number of cars
Z= the number of cars an engine can pull.

Then:
Z = N/(X+Y)

If For CSX's statement to work for A= SD70MAC, assuming Y/Z=5, and N/Z = 40, than:

Z > 30.

[Green Maned Lion]

All diesel locomotives are diesel-electrics, possibly with the exception of some smaller DMUs. A diesel engine is about torque. For example, Volvo's D16E660 makes approximately 640 bhp, but 2286 ft-lb of torque. Another example is the VW Passat 2.0 litre diesel from a few years back, which made 136 hp, but 248lb-ft of torque. For an equivlency, consider their base gas motor from the same car, a 1.8 litre turbocharged unit making 170bhp, and 166lb-ft of torque.

Amtrak's P42DC, for instance, makes 4,200 Bhp. I haven't found the torque figure, but it relative to the Volvo, it makes 15,000 lb-ft of torque, approximately. That kind of torque would bust the hell out of any kind of multi-geared transmission I can think of. Electric motors, on the other hand, because they are comfortable with spinning at pretty much any speed from 1 rpm to 13,000 RPM don't really need a transmission unless you want a combination of high top speed and quick acceleration, such as with the Tesla electric car.

So instead of transmitting the power to the wheels via a drive shaft, they use a generator to turn it into electricity. Then they transmit the electricity from the diesel engine to electric traction motors on each bogie or axle (not sure which), which then turn the electricity back into torque and motion. The electrical components merely serve as a transmission, if you will. There are some newer experiments using batteries to recapture electricity, but they wouldn't make much difference. Especially on a screamer engine like Amtrak's with HEP that requires the engine to turn at a constant rpm, and thus you don't save much due to lower loads on it.

[WhoozOn1st]

WhoozOn1st999, on Fri, Feb 1, 2008, 11:29 AM, said:

Okay, I finally broke down and asked CSX directly. Talk about jumping through hoops!

Now taking bets. Current line:

Response from CSX - 100-1

Straight answer - Not enough zeroes to 1.

Holy moly, I actually received a snail mail response from CSX:

Thank you for your inquiry about our advertising.

Our ad states "trains can move a ton of freight 423 miles on a single gallon of fuel," and it is correct. The 423 is calculated by dividing the total tons hauled by a single freight train by the total gallons of fuel used. So, on a per mile, per ton basis, the amount of fuel needed is extremely low. In fact, it is so low that trains are between three and four times more fuel efficient than trucks.

So, even though it takes more than one gallon of fuel to power a train for 423 miles, the train actually uses less fuel than the more than 280 trucks it would take to haul the same amount of freight.

Thank you again for contacting us.

Sincerely,

TellCSX Team

-----

Condescending attitude aside - "...it takes more than one gallon of fuel to power a train for 423 miles..." - I think PRR 60's estimation is more satisfactory overall.

[Green Maned Lion]

Well, a lot of trains are double-stackers these days, right? Which means each car carries two trucks worth of 40-foot shipping containers. So that indicates the freights are 140 cars long. Are they that long? Wouldn't that make for quite a heavy whip effect?

[Green Maned Lion]

From what I read of their calculations, they actually were as un-deceptive as possible about it. Were you to remove the fuel taken for acceleration and only advertised the fuel taken to move the freight one mile while in motion, the number would have probably been higher. Excluding going up hill, it takes very little power to keep something like that moving- just enough to overcome wind resistance. The concept of inertia keeps it moving. Otherwise, it wouldn't take a mile to stop a speeding freight during an emergency brake.

I'm no fan of America's Broad Gauge (a name some railfans give CSX due to its abominable track maintenance) but in this case they were being completely honest.

[AlanB]

Guest, on Thu, Feb 14, 2008, 01:02 AM, said:

It's intentionally deceptive advertising (isn't most?) I think a better question for CSX is, how much fuel is required to move that ton of freight the _first_ mile. Sure, if you get to average out over every mile they travel, then I am sure there numbers are accurate. Still, it's intended to make the viewer draw inaccurate conclusions.

It's only deceptive and inaccurate if they are comparing the average for CSX and comparing that number to the fuel consumed by the needed amount of trucks required to move the same freight for the first mile. Otherwise, if they are comparing the fuel for the train over say 100 miles vs the fuel for the fleet of trucks needed to move the same load over 100 miles, then it is a perfectly fair and accurate comparison.

[Trogdor]

not1word, on Sun, Mar 16, 2008, 01:02 PM, said:

This ad has been bothering me, too. Perhaps I'm missing something crucial, but even with everyone's calculations, all we've been talking about is freight tons and gallons consumed, with no mention of number of miles travelled. One can use all the abstruse formulas desired, but at the base is still the basic idea that X number of miles travelled divided by Y number of gallons of fuel consumed equals Z number of miles per gallon used. This is the mental thrust of the commercial which is aimed at the average listener. It has to be the presumed basis of the reasoning, the commercials being aired as they are, and, one hopes, the assumption that can be made of the average listener. Most people don't take too much time to figure in ton/miles, double stack train cars and rates of inertia while driving from the take out window to the next stop.

What is at the center of the ad is honesty. I don't believe that their locomotives are actually able to travel 423 miles on a single gallon of diesel fuel. That would be a very simple thing to prove, by putting a gallon of diesel in a tank, and seeing if the engine is able to go 423 miles. My simple mined guess is that it would not (even without a full load on), but this is the mental picture being put forward by the ad. The reality gets even worse, since CSX is running this ad as some sort of proof of rail road's efficiency and environmental concern. Actually, rail road is less efficient than OTR trucking, since rail cars can only travel on restricted rail ways and can only pick up/drop off loads at centralized locations, often very far away from the actual final destination of the freight.

But then, that's just the view from where I'm sitting.

It is no less honest to use ton-miles per gallon when calculating fuel efficiency of freight engines than to use cost/loss per passenger-mile when calculating the financial performance of a passenger train.

Using ton-miles (or passenger-miles, as the case may be) as the basis for calculation is really the only way to get a valid comparison when you want to consider all factors. You can't just say that the engines run at x miles per gallon. You have to do it in terms of the amount of freight that is moved. After all, CSX is in the business of moving freight, not engines. The simple, plain truth that the ad is trying to convey is that if you are trying to move a lot of stuff, you will do so on less fuel by rail than by truck. Whether you use ton-miles per gallon, or stone-furlongs per barrel, you have to consider the actual payload being moved when you want a true comparison. After all, a single-occupant SUV uses less total fuel than a 40-passenger bus, but if you wanted to move 40 people, the bus is the better way to do it.

I don't understand why this is the subject of so much debate.

[Green Maned Lion]

A Ford Excursion, getting 10 mpg, when loaded to its capacity of eight passengers, gets 80 passenger miles per gallon. Ton/miles per gallon is not a measure of consumption, but of efficiency.

I need to move 400 tons of (800,000 lbs) of stuff 423 miles. A a truck hauling 80,000 lbs gets about 4 miles to the gallon, IIRC last time I was looking at peterbilts. So to move that 400 tons, I need 10 trucks. So I am going to move these items .4 miles for every gallon consumed, so to travel the distance of 423 miles, I need to us 1057 gallons of diesel fuel. Alternatively, I can tack it onto the back of a freight train (CSX isn't all that much more efficient than its competitors, btw), and it will take 400 gallons. So this 18-wheeler moves one ton of freight 162 miles.

It ain't a ridiculous increase in efficiency, you understand. About 2.5 times. But its a big solid demonstration of the advantage of moving things in bulk.

To further the comparison, let us move these 400 tons of stuff via a Ford F350 with single rear wheels, which can carry 4000 lbs, or 2 tons worth of stuff. It gets around 10mpg fully loaded. To carry 400 tons, you need 200 F350s. It will take 42.3 gallons of fuel per truck to do the move, or a total of 8460 gallons of fuel. This F350 moves 1 ton of frieght 20 miles per gallon of fuel.

Its the best way to measure haulage efficiency of bulk freight. And in this regard, the railroad is clearly superior.