How far does the average diesel locomotive go between refuels, and how many MPG does it get? Are they all in the same range, or does it vary?
For example, say that a train with a 3000 gal. fuel tank travels 100 miles each day, every day. On day 1, it starts its work with a full tank. How many days later would it need a refuel?
Thanks in advance.
Tonnage? grade & curvature? MU’d/DPU’d with? Engineer qualification?, wind? axle count?
I think you get the point…
In Idle, a large diesel locomotive burns maybe 5? gallons per hour. At full power it burns something over 200 gallons per hour. So you need to make some guesses about how much time it’s spending idling and how much at full power, and how fast it’s covering the miles.
As others said above, everything depends on the route, speed, and weight of train! But I think what you’re looking for is averages.
Here’s an example that may help. A particular coal train I have worked with runs 1,670 miles round-trip between the mine and the power plant. The route is mountainous throughout, with numerous long ascending grades. The train is 135-cars long with gross weight of 18,500 tons (including locomotives). Each locomotive carries 5,000 gallons of fuel. In that round trip, the train will refill twice, each time each locomotive taking on about 4,000 gallons. So:
Total fuel consumed round trip = 20,000 gallons
Total mileage 1,670
Miles per gallon per locomotive = 0.41.
But again, this is only a specific case. Other cases are much much different.
Another way of obtaining an average is to use the US Energy Information Administration’s averages for the U.S. as a whole. EIA found that in 2006, the BTUs per ton/mile average for freight transportation modes were:
So in rough equivalent numbers, if the average 80,000 lb. semi-trailer combination is getting 8 mpg to move 26 tons of freight, the average train is getting 66 mpg to move 26 tons of freight.
RWM
One carrier that I am aware of, for locomotive management purposes, rates the GE AC’s for 1100 miles for a full 5000 gallon tank in unit train service. Other, less stressed, services have longer mileage intervals.
Of course the idea is that the train is moving a lot more tonnage than another form of transportation with the same fuel, so its more efficient. Then again I would say that anyway since I am a train person. I have seen varying accounts, I do know that railroads sometimes ordered larger fuel tanks to get longer distances out of their engines. I don’t know, maybe type of train would make a difference too, but the more knowlegable members here certainly can answer this better.
Hi,
great post Railwayman. This shows very well how efficient the different modes of transportation really are. Surprised that water uses more fuel then rail.
Frank
Here’s some dated information on the SD-40 from “Fuel Efficiency Improvement in Rail Freight Transportation,” J N Cetenich, FRA-ORD-76-136, Dec, 1975.
Throttle Position Delivered Horsepower Fuel Rate (gal/hr)
8 3100 168
7 2550 146
6 2000 108
5 1450 79
4 950 57
3 &
I am not sure how you have reached that conclusion, which is contrary to my experience and knowledge. The table you cited is interesting. An SD40-2 doesn’t deliver 3,100 hp. It delivers 3,000 hp into the flywheel of the main generator, and about 2,500 hp onto the rail. That’s the only delivered power that matters.
According to EMD, the SD40-2 consumed 164.4 gph at 3,000 hp output into the flywheel, similiar to the table you cited, but the E8 consumed 188 gph at 2,250 hp into its flywheels instead of the 114 you cite.
Here’s the numbers from EMD for horsepower per gallon per hour at notch 8 (which is the most fuel-efficient notch in terms of maximum horspower per gallon consumed):
Conclusions:
I am inferring from your post that the 645 engine really didn’t accomplish as much as you think it should, relative to the 567. I may be inferring incorrectly, but allow me a comment on that. Horsepower per cubic inch of displacement in an engine family often doesn’t increase when total displacement increases, because the engine designers want to live within a certain maximum pressure within the cylinder that’s commensurate with the capabilities of the design to resist that pressure. It’s possible to increase that pressure but only by making the engine much heavier, and/or accepting a much higher maintenance cost and much lower engine longevity. Weight and dimensional increase outcomes are usually not acceptable in the highly restricted weight/dimensional envelope in a rail application. While it’s true that engine technology improves over time, often
I know very little of naval engineering, but from what I can gather, the problem is the bluntness/width of the hull that is necessary to efficiently accommodate very large tonnages for the amount of steel and overall length of ship necessary to fit in ports, docks, locks, etc. That creates enormous resistance to motion through the water. In order to get high fuel efficiency, the hull shape needs to be more needle-like.
RWM
What I would like to know is why does using the dynamic brake cause an increase in fuel usage?
I was having some thoughts on this line yesterday, but did not work them out as RWM did. Certainly, a streamlined prow and a stern that is shaped so as to reduce turbulence will increase fuel efficiency. I have never examined the floats of a catamaran, but I believe that they would be shaped so that not only do they lift the body of the craft out of the water, they also cut through the water more smoothly. Does anyone have any knowledge of relative fuel efficiency for a catamaran (such as those used by the Victoria Clipper)?
Perhaps one reason for uisng using (did my keyboard ever foul up on that!) barges is less roadway upkeep expense?
Johnny
They have to rev the engine some to run the generator – this is needed to produce what they call excitation voltage for the traction motors so they act as generators. Acting as generators they act as brakes.
I suppose you could design self-exciting generators – the power output of the generator in turn could produce voltage across the field windings to make them work as generators. This is not perpetual motion as you are still converting shaft power to electric power, and you may need some initial excitation or magnetism in the field to get this going.
But I guess it was a lot simpler, safer, cheaper, easier to generate the traction-motor-as-generator excitation voltage with the main generator during dynamic braking and hence dynamic braking uses a little bit of fuel. With expensive fuel one could pursue alternatives to this arrangement, but given the costs and benefits it may not be worth it.
What the AC traction motor locos do is something I don’t know.
He gave figures for the SD40-2, on which the traction motor blower is connected directly to the 16-645-- in other words, the blower only runs full speed if the prime mover is at full speed. The traction motors still need cooling in dynamic brake.
So apparently it takes 25 gal/hr to run a 16-645 at full speed with next to no load.
Don’t recall what produces TM excitation current in dynamic-- probably the D14 auxiliary alternator? Not the main generator, in any case.
My WAG on conclusion #2 is that the fuel consumption may include the steam generators, otherwise I’d also wonder what was killing the fuel economy of the E’s.
I’d wager that conclusion #1 holds more for the 2 cycle engines, and would assume 4 cycle engines would have a smaller increase in fuel economy.
I don’t think it’s the steam generators. More likely it’s transmission inefficiency.
I can’t think of any 4-stroke locomotive prime movers that did not have turbochargers.
RWM
A number of the early Alco and Baldwin engines were naturally aspirated. The 660 HP 539 engine in the Alco S-1 had no turbocharger.
The fuel saving from turbochargers on EMD two stroke engines came from the turbocharger uncoupling from its gear drive from the crankshaft at notch 7 (or about). A look at the specific fuel consumption curve for a turbocharged EMD takes a sudden drop around notch 7 at the point that the considerable power being used to drive the blower becomes available at the generator.
M636C
Now why didn’t I recall the 539? Since I worked on them now and then? Old age I guess.
The illustration on the turbo decoupling is a good one.
RWM
for one thing the E units were 2-567 engines not just the 1 that were in hood units. therefor more fuel used to make the 2250 horsepower
I’m pretty sure the VO series engines from Baldwin were four stroke, and they were normally aspirated.