How far can Amtrak locomotives go on a full tank?

[MIrailfan]

1 loco, and same question with 2.

 

[Palmetto]

Impossible to give one, pat answer, in my view. It's like your car: the faster you run, the more fuel is used. Do train engines actually have an MPG rating?

 

[MARC Rider]

This is from a poster presented at the 2019 TRB meeting in Washington. They were studying the effect of operating conditions on the Piedmont Service (mostly because I think it was a North Carolina University that did the study)



A gallon of diesel fuel is about 3.2 kilograms. So in most cases, it looks like the train is getting about 1 mpg. The Raleigh-Cary stretch uses the most fuel per mile because (1) it is shorter than the distance between the other station pairs, and (2) there are a couple of curves in the stretch that require deceleration and acceleration.

Please note that even though these investigators tried to consistently use SI (metric units) in this presentation, when it came to emissions/fuel consumption measurements, the used the *******ized mix "kg/mi."

Here's the full poster:



It's one of the few places I've seen actual fuel consumption test data for a passenger train. Note that this is the Piedmont Service. These consist of a locomotive at each end of the train and about 4 cars in the consist. A longer train might be heavier, and hauling one over the mountains might use up more fuel than rolling nonstop across straight, flat terrain.

The real fuel consumption performance that transportation planners concern themselves with is not raw gallons per mile of the train, but rather the gallons per passenger-mile or gallons per ton-mile. To know that you need to know the total passenger capacity of the train and its "load factor" (the average percentage of actual passengers on board to the total capacity.) Thus, a longer, heaver train full of passengers might actually have better measurement of gallons per passenger mile than a shorter, smaller train with fewer passengers even though the larger train uses more gallons per mile.

 

[me_little_me]

I think the question refers to an average rather than a specific amount based on a specific train in a specific situation.

 

[crescent-zephyr]

Doesn’t really answer the question but I was on the Crescent once and they had to drop a locomotive off in Atlanta because it was messing up the HEP (the power continued to cycle on and off).

Because it was only 1 Locomotive we had to stop and fuel in the NS yard in Charlotte (so full “service stop in Charlotte at the station - and then a fuel stop in the ns yard in Charlotte as well).

 

[MIrailfan]

Well maybe 500 miles? Ok m guessing this now cuz I remember the sunset limited eastbound stops at Tuscon for fuel and it's 500 miles between them.

 

[MARC Rider]

From Washington DC to Jacksonville FL it's 752 miles, and when I ride the Silvers southbound, that's where they fuel. The station stop in Florence SC (8 min) seems to be too short to be a fueling stop. More like a crew change stop.
From Washington DC to Savannah GA is 602 miles, and I've ridden the Palmetto all the way, and I know there was no fueling stop.
From Washington DC to Chicago on the Capitol Limited, it's 780 miles, and I don't think there's a fueling stop on that one, either.

 

[Qapla]

There was a study done that had these results

Results of the tests showed that the average fuel consumption for the 157.7 mile trip was 368 gallons and that the average fuel use efficiency was 277 ton-miles per gallon.

The P42DC GENESIS holds 2200 gallons of fuel

That's why the Silvers can go from JAX to DC without needing fuel

 

[Dutchrailnut]

yes it has 4 x 550 gallon tanks ,
but full is 2000 gallons or it can not recover fuel from a leaking tank.

 

[Cal]

Well maybe 500 miles? Ok m guessing this now cuz I remember the sunset limited eastbound stops at Tuscon for fuel and it's 500 miles between them.

Much more, as MARC rider said. I think they refuel there because the next refueling stop is San Antonio (maybe El Paso ,but I didn't see them refuel the last few times I was there) and they can't make it all the way there without refueling.

 

[MIrailfan]

Much more, as MARC rider said. I think they refuel there because the next refueling stop is San Antonio (maybe El Paso ,but I didn't see them refuel the last few times I was there) and they can't make it all the way there without refueling.

So they top off the tanks.

 

[MIrailfan]

Better than being stranded on remote track.

 

[west point]

How much time at run 8 can locos go without refueling ?

 

[Cal]

How much time at run 8 can locos go without refueling ?

Depends on the route, it would definitely differ between the Sunset and the CZ

 

[Qapla]

Not sure how much direction plays on this - many claim that it is downhill when you run from DC to Florida ...

 

[MARC Rider]

Not sure how much direction plays on this - many claim that it is downhill when you run from DC to Florida ...

Australians might disagree on that!

Also, Washington is more or less at sea level. Miami is more or less at sea level. How can it be a downhill run?

 

[jis]

Australians might disagree on that!

Also, Washington is more or less at sea level. Miami is more or less at sea level. How can it be a downhill run?

And Orlando is 82' above MSL, so there is a bit of a climb involved to get there

 

[Siegmund]

The study qapla quoted sounds very reasonable to me:

Results of the tests showed that the average fuel consumption for the 157.7 mile trip was 368 gallons and that the average fuel use efficiency was 277 ton-miles per gallon.

Freight engine fuel performance is often cited in ton-miles per gallon --- and figures around 500 ton-miles per gallon are typical for freight. It wouldnt be surprising that a passenger train, devoting a few hundred horsepower to the hotel load, accelerating more, and running at higher speeds, would do somewhat worse.

I assume that when you see a single ton-miles per gallon figure, the expectation is that uphill and downhill will cancel each other out over the long haul - and that speed is a relatively minor factor compared to other sources of drag. It seems that is likely to cease to be true for fast freights.

The longest Amtrak trains are going to run a tad over 1000 tons (135 tons per engine and ~80 tons per Superliner), so presumably need to budget for ~4 gallons per mile. Anything between 500 and 1000 miles between fuel stops seems plausible. If memory serves, the Builder is refueled at St. Paul, Havre, and Spokane.

 

[MARC Rider]

I assume that when you see a single ton-miles per gallon figure, the expectation is that uphill and downhill will cancel each other out over the long haul - and that speed is a relatively minor factor compared to other sources of drag. It seems that is likely to cease to be true for fast freights.

The EPA/NHTSA greenhouse gas/fuel economy standards for heavy duty diesel trucks use a simple model to estimate relative GHG emissions (which are more or less the same as fuel economy). For class 3-7 trucks, the only adjustable factor in the model is the tire rolling resistance. For the class 8 tractor trailers (i.e. the 18-wheelers), the model includes adjustments for both tire rolling resistance and drag coefficient. We spent a lot of time (and your tax dollars) figuring out how to do tests to measure drag coefficient of these trucks. For planning purposes, our general rule of thumb was that Aerodynamic drag wasn't much much of a factor when the speed dropped below 45-50 mph. That's why the rule doesn't bother with drag coefficient for the class 3-7 delivery-type trucks, but does for the class 8 line-haul highway trucks. I know, even delivery trucks sometimes use the freeway, but on average their speeds are less.

We also tested various trailer side skirts and other devices that claimed to reduce aerodynamic drag. Most of our tests were on at constant speed of about 62 mph (i.e., 100 km/hr).

I would expect that aero drag isn't a real big deal for subways, light rail, commuter trains (there are exceptions, like MARC and NJT that run full out on the NEC). Actually, it probably doesn't even matter for most Amtrak long distance trains, which average about 40 mph point to point, although those trains should be going faster and thus should be designed with aerodynamic drag in mind. It is important to design for aerodynamics for the faster corridor trains that consistently run faster than 60 mph, and, of course, high speed rail.

 

[west point]

The biggest load of course is AutoTrain. It refuels at Florence and at terminals.

 

[Dutchrailnut]

actually the Auto train is not , no stops , no loss of HVAC during open doors , pretty much a constant speed and not really operating at Passenger speeds.
add to that that overall the entire trip is not steep by any means .

 

[Siegmund]

actually the Auto train is not , no stops , no loss of HVAC during open doors , pretty much a constant speed and not really operating at Passenger speeds.
add to that that overall the entire trip is not steep by any means .

Those latter points are all true... but the Auto-Train is vastly heavier than any other Amtrak train: a random video grab from youtube showed 2 units, 15 Superliners, and 22 autoracks, which comes to about 2500 tons: even at freight-train-like efficiency it is burning close to twice as much fuel per mile as any other Amtrak train, and is maybe the one train in the system where covering 855 miles without refueling is completely out of the question.

Florence is conveniently near the midpoint of the run - and a good thing too. I hope that the auto train does considerably better than the 277 ton-miles per gallon cited upthread or it would be on fumes after 400 miles. But I would guess 500 or 600 would be the autotrain's limit.