I've been wondering what a locomotive's miles per gallon is. Can anyone here help me?
Thanks ahead of time.
A modern locomotive gets about 0.5 miles per gallon.
Before you call that inefficient, remember that one railcar carries about 4 times as much as a truck, so a 100 car train carries approximately 400 trucks' worth of cargo.
If my math is correct, a truck would have to get about 200 MPG to be equally efficient... Then you have to factor in how much more congested US 40 would be without the BNSF's Transcon route... And with 100 trains a day, each carrying 400 trucks worth of cargo...
Do you think US 40 car can handle 40,000 more trucks every day? Me neither...
And yes, this is the case I make whenever people talk about how dangerous trains are!
TrainManTyA modern locomotive gets about 0.5 miles per gallon
It really isn't quite that simple. Look at Al Krug's tables of locomotive fuel consumption and you will see why. An SD-40, for example, uses 167.7 gallons per hour in run 8. At 60 mph, that computes to 2.795 gallons per mile. But you could be struggling up hill at 15 mph in the same notch and burning 11.18 gallons per mile. Lower notches of course yield better mileage and you may not need full power to achieve a given speed
Another way to look at Ty's comparison with trucks is by horsepower per ton. A typical freight train may get by with one or two horsepower per ton, depending on how fast it needs to run. Some hotshots will be handled with four to six hp/ton. A 40 ton truck will have at least 600 hp, and probably more if it is a newer model. So you get over the road with at least 15 hp/ton. The railroad's superior efficiency is clear and Ty makes a good point about the number of trucks it would take to replace trains. According to government figures, in 2003 railroads used 3.8 billion gallons of diesel fuel vs. 26.8 billion gal for trucks. I'll bet the trucks didn't move seven times as much cargo.
Incidentally regarding steam power, I found a note (don't know the source) which says specific coal consumption for a steam locomotive is 2.2 pounds/dbhp/hr. Thus, a Berkshire for example, exerting 4000 drawbar hp, would use 4.4 tons per hour. Mileage per ton of coal varies of course with speed. Maybe someone smarter than me can confirm that bit of info, or challenge it.
Tim
tpatrickIt really isn't quite that simple. Look at Al Krug's tables of locomotive fuel consumption and you will see why. An SD-40, for example, uses 167.7 gallons per hour in run 8. At 60 mph, that computes to 2.795 gallons per mile. But you could be struggling up hill at 15 mph in the same notch and burning 11.18 gallons per mile. Lower notches of course yield better mileage and you may not need full power to achieve a given speed
Yes, it definetely does depend on the speed. I wrote that as a average number; the one that a modern loco (SD70, ES44, etc) gets on level ground with an average train going an average speed. It all depends on the grade and throttle notch. I've seen a pair of CSX SD70Ms stall on the Jamesville grade just West of Worcester, MA (I think one failed, it certainly wasn't sounding good as the train passed me at the foot of the grade) and I bet they weren't getting very good mileage! But downhill on some grades they can just coast and burn no fuel at all. What goes up must come down... It all evens out at some point.
TrainManTyWhat goes up must come down... It all evens out at some point.
What goes up must come down... It all evens out at some point.
Going downhill still burns fuel. The engine revs when in DB, or if (god forbid) you have to drag the train down the hill(set a brake and pull the train down the hill).
tpatrick [A 40 ton truck will have at least 600 hp, and probably more if it is a newer model. So you get over the road with at least 15 hp/ton.
[A 40 ton truck will have at least 600 hp, and probably more if it is a newer model. So you get over the road with at least 15 hp/ton.
The typical fleet over the road truck will only have about 4-500 hp with 600hp being on the extreme side.
If I were to own and operate a truck over the road (which I'd never do) I'd spec the 600hp motor and gears to get me to 120mph. If I were to own a fleet I'd have 400hp engines and 64mph governors.
Since the bulk of trucking is done by large fleets like Schnieder, Yellow, Wal-Mart, J.B. Hunt and so on, you might want to re-calculate some.
Even after all the variables are accounted for, on both trucks and trains, trains are still about 5 times more efficient than trucks in tons, per mile, per gallon.
If there had been at least one brain working at the Federal Government in the 1950's, the tariffs and laws would have been quickly changed to encourage piggy back. Instead, they played around for years, making it harder and more expensive and the railroads and the truckers, who had to fight for 30 years to get it deregulated.
Had the government gotten out of the way sooner, it is very likely much more of the long distance truck traffic would have been on flat cars years ago. The highways would be safer, oil consuption would be lower, the world would be a better place. The unintended consequence of too much government.
Sheldon
The locomotive I work around averages 10-11 gallons to the mile. Of course, we're burning bunker oil to boil water ...
TrainManTyHmm... A steam locomotive is really inefficient... Just think of how many gallons of water it uses per mile!
Probably works out to be how many gallons to a mile. It varies according to the load also.
CZ