P42 Miles Per Gallon

[OlympianHiawatha]

What is the average miles per gallon for 2 P42s pulling a "typical" 9-10 car Superliner consist? I know this probably isn't a straight forward easy to calculate figure but something in the ballpark. And if 2 engines are doing the work versus 1, does each engine get "better" mileage since the load is shared?

 

[henryj]

I have no idea. But here are some links.

http://strredwolf.livejournal.com/467957.html

http://cs.trains.com/TRCCS/themes/trc/forums/thread.aspx?ThreadID=147702&PostID=1637281&PermaPostID=1637281

Locomotives are actually rated in GPH or Gallons per Hour at each run level. So mileage would depend on how hard the engine was working and how far it went at that level. To get a good reading what you really need is fuel consumption for a particular train end to end, start to stop. Then figure out passenger capacity and get a figure that is mileage per passenger on that particular route. I know you have seen the CSX add that advertises they can haul a ton of freight 400 miles on a gallon of fuel. How far can Amtrak haul a passenger on a gallon of fuel? Interesting question.

Here is a site that tries to answer the question:

http://en.wikipedia.org/wiki/Fuel_efficiency_in_transportation

TrainsUK freight trains average about 1.5–2.0 MPG loaded. Compared with road transport it is very efficient; if lorries did the same trip they would use 70% more fuel than a freight train. UK passenger trains average from 8 MPG to 12 MPG.

Freight: the AAR claims an energy efficiency of 457 ton-miles per gallon of diesel fuel in 2008[26]

The East Japan Railway Company claims for 2004 an energy intensity of 20.6 MJ/car-km, or about 0.35 MJ/passenger-km[27]

a 1997 EC study[28] on page 74 claims 18.00 kWh/train-km for the TGV Duplex assuming 3 intermediate stops between Paris and Lyon. This equates to 64.80 MJ/train-km. With 80% of the 545 seats filled on average[29] this is 0.15 MJ/passenger-km.

Actual train consumption depends on gradients, maximum speeds and stopping patterns. Data was produced for the European MEET project (Methodologies for Estimating Air Pollutant Emissions) and illustrates the different consumption patterns over several track sections. The results show the consumption for a German ICE high-speed train varied from around 19–33 kW·h/km (68–120 MJ/km; 31–53 kW·h/mi). The data also reflects the weight of the train per passenger. For example, the TGV double-deck ‘Duplex’ trains use lightweight materials in order to keep axle loads down and reduce damage to track; this saves considerable energy.[30]

A Siemens study of Combino light rail vehicles in service in Basel, Switzerland over 56 days showed net consumption of 1.53 kWh/vehicle-km, or 5.51 MJ/vehicle-km. Average passenger load was estimated to be 65 people, resulting in average energy efficiency of 0.085 MJ/passenger-km. The Combino in this configuration can carry as many as 180 with standees. 41.6% of the total energy consumed was recovered through regenerative braking.[31]

A trial of a Colorado Railcar double-deck DMU hauling two Bombardier Bi-level coaches found fuel consumption to be 128 US gallons (480 l; 107 imp gal) for 144 miles (232 km), or 1.125 mpg-US (209.1 L/100 km; 1.351 mpg-imp). The DMU has 92 seats, the coaches typically have 162 seats, for a total of 416 seats. With all seats filled the efficiency would be 468 passenger-miles per US gallon (0.503 L/100 passenger-km; 562 passenger-mpg-imp).[32]

Note that intercity rail in the US reports 3.17 MJ/passenger-km which is several times higher than reported from Japan. Independent transportation researcher David Lawyer attributes this difference to the fact that the losses in electricity generation may not have been taken into account for Japan[33] and that Japanese trains have a larger number of passengers per car.[34]

Modern electric trains like the shinkansen use regenerative braking to return current into the catenary while they brake. This method results in significant energy savings, whereas diesel locomotives (in use on unelectrified railway networks) typically dispose of the energy generated by dynamic braking as heat into the ambient air.[citation needed]

This Swiss Railroad company SBB-CFF-FFS cites 0.082 kWh per passenger-km for traction.

AEA carried out a detailed study of road and rail for the United Kingdom Department for Transport. Final report

Amtrak reports 2005 energy use of 2,935 BTU per passenger-mile (1.9 MJ/passenger-km).[35]

The Passenger Rail (Urban and Intercity) and Scheduled Intercity and All Charter Bus Industries Technological and Operational Improvements - FINAL REPORT states that "Commuter operations can dissipate more than half of their total traction energy in braking for stops." and that "We estimate hotel power to be 35 percent (but it could possibly be as high as 45 percent) of total energy consumed by commuter railways."[36] Having to accelerate and decelerate a heavy train load of people at every stop is inefficient despite regenerative braking which can recover typically around 20% of the energy wasted in braking.

US Passenger transportationThe US Transportation Energy Data Book states the following figures for Passenger transportation in 2006:[42]

Transport mode Average passengers

per vehicle BTU per passenger-mile MJ per passenger-kilometre

Vanpool 6.1 1,322 0.867

Efficient Hybrid 1.57 1,659 1.088

Motorcycles 1.2 1,855 1.216

Rail (Intercity Amtrak) 20.5 2,650 1.737

Rail (Transit Light & Heavy) 22.5 2,784 1.825

Rail (Commuter) 31.3 2,996 1.964

Air 96.2 3,261 2.138

Cars 1.57 3,512 2.302

Personal Trucks 1.72 3,944 2.586

Buses (Transit) 8.8 4,235 2.776

Looks like Vanpool is the most efficient form of transport. Amtrak rates fourth.

 

[Ryan]

Should be pretty easy to figure, you can read the fuel remaining on digital gauges on the side of the locomotive. Check it between two stops and you can calculate it pretty easy.

 

[transit54]

Amtrak lists gallons per train mile in their performance reports, which can be obtained here:

http://www.amtrak.com/servlet/ContentServer?c=Page&pagename=am%2FLayout&cid=1241245669222

Based on the Dec 2010 report (the most recent) trains average between 2.2 and 2.5 gallons per train mile. In the figures your looking for, that would be between .4 and .46 miles per gallon.

 

[Acela150]

So a P42 goes less then half a mile on a gallon of diesel fuel?? WOW! That's crazy on how short of a distance it goes. I would think at least two miles. I was wrong. :lol:

 

[the_traveler]

But how many MPGs does it get on 89 octane unleaded gas?

 

[Trogdor]

So a P42 goes less then half a mile on a gallon of diesel fuel?? WOW! That's crazy on how short of a distance it goes. I would think at least two miles. I was wrong.

Given how large the engine is and how much power it puts out, I don't know why you would expect it to get any more than that.

The real measure of fuel efficiency isn't miles per gallon, it's payload-miles per gallon (passenger-miles or ton-miles, as the case may be). A P42 getting 0.4 miles per gallon pulling a train with 100 passengers gets 40 passenger-miles per gallon. That's certainly better than most single-occupancy cars out there. Put 400 people on a train (a full Hiawatha, for example), and you get 160 passenger-miles per gallon.

 

[Green Maned Lion]

But how many MPGs does it get on 89 octane unleaded gas?

Zero. Putting 89 Unleaded into a P42 would create damage to its valve gear and fuel delivery systems, not to mention its block, pistons, etc. that would cost, I would guess, hundreds of thousands of dollars to fix. You would, in all likelyhood, need to replace the entire prime mover.

 

[transit54]

To put more numbers to it, from the Nov 2010 report (it's in December's report also, I just happened to have Nov 2010 in front of me), Amtrak used 2.2 gallons per train mile and traveled 3,129,000 train miles during the month of November. During that time they accumulated 528,450,000 passenger miles. That works out to 76.8 passenger miles per gallon.

Amtrak actually had 1,081,300,000 seat miles available during November. So if every seat was sold out on every Amtrak train each day, Amtrak could theoretically obtain 157.1 passenger miles per gallon.

Now, granted, this assumes that all trains involved were diesel, which they were not - thus the actual efficiency could vary if electric trains were more fuel efficient, for instance. But these numbers at least give a back of the envelope estimate of Amtrak's efficiency in comparable terms.

 

[jis]

US Passenger transportation - The US Transportation Energy Data Book states the following figures for Passenger transportation in 2006:[42]

Transport mode Average passengers

per vehicle BTU per passenger-mile MJ per passenger-kilometre

Vanpool 6.1 1,322 0.867

Efficient Hybrid 1.57 1,659 1.088

Motorcycles 1.2 1,855 1.216

Rail (Intercity Amtrak) 20.5 2,650 1.737

Rail (Transit Light & Heavy) 22.5 2,784 1.825

Rail (Commuter) 31.3 2,996 1.964

Air 96.2 3,261 2.138

Cars 1.57 3,512 2.302

Personal Trucks 1.72 3,944 2.586

Buses (Transit) 8.8 4,235 2.776

Looks like Vanpool is the most efficient form of transport. Amtrak rates fourth.

Interesting! It uses the following interesting parameters for average number of passengers per vehicle to do its what appears to be questionable conclusions:

Van pool 6.1 - a very tightly packed van

Rail (Intercity) 20.5 - a very sparsely used train

Rail (Transit Light and Heavy) 22.5 - clearly we are not talking new York Subway or even HBLRT here

Rail (Commuter)31.3 - again we are not talking of LIRR, MNRR or NJT here.

Buses (Transit) 8.8 - maybe they should replace those routes with the tightly packed vans

Isn't number crunching fun? I have no doubt that all of that calculation is based on some real set of numbers spanning all transport everywhere in US. But the numbers are somewhat useless as a means for planning anything.

 

[the_traveler]

Transport mode Average passengers per vehicle BTU per passenger-mile MJ per passenger-kilometre

Vanpool 6.1 1,322 0.867

Van pool 6.1 - a very tightly packed van

I'd hate to meet that .1 passenger!

(Maybe it was too tightly packed!

)

 

[Bigval109]

So a P42 goes less then half a mile on a gallon of diesel fuel?? WOW! That's crazy on how short of a distance it goes. I would think at least two miles. I was wrong. :lol:

Well let us remember it isn't a car. :blink: In fact the engine weighs maybe 100,000 lbs plus the weight of the cars behind it. It has 16 cylinders or maybe 12 and each cylinder is the size of maybe a washing machine just a guess. I think it does good to get that much. I use to have a 455 olds that only got 8 mpg. :wacko: I was always crying at the gas station and gas was only .25 a gallon back in 1972. but it didn't last long in that Olds. The car was great though. I certainlly could use some .25 gallon gas today.

 

[the_traveler]

I certainlly could use some .25 gallon gas today.

Eat lots of baked beans - and you'll have plenty of gas!

 

[George Harris]

Interesting! It uses the following interesting parameters for average number of passengers per vehicle to do its what appears to be questionable conclusions:
Van pool 6.1 - a very tightly packed van

Rail (Intercity) 20.5 - a very sparsely used train

Rail (Transit Light and Heavy) 22.5 - clearly we are not talking new York Subway or even HBLRT here

Rail (Commuter)31.3 - again we are not talking of LIRR, MNRR or NJT here.

Buses (Transit) 8.8 - maybe they should replace those routes with the tightly packed vans

Isn't number crunching fun? I have no doubt that all of that calculation is based on some real set of numbers spanning all transport everywhere in US. But the numbers are somewhat useless as a means for planning anything.

Exactly right: This sort of stuff is an outstanding example of the saying, "Figures don't lie, but liars figure."

If you changed the passenger count to realistic figures, the results would be completely different. Back in the 1960's passenger trains with higher than 20.5 average passenger counts were permitted be discontinued by the ICC.

 

[Trogdor]

Well, the stats do say "passengers per vehicle" not "passengers per train." I'm not sure what counts as a vehicle in this case, but if you have seven cars and a locomotive, does that count as eight vehicles? A train with a locomotive, a baggage car, dorm car, one sleeper, dining car, lounge, and two coaches might have 160 people on it, but it's entirely possible that these stats would say that "passengers per vehicle" would be 20.

 

[PRR 60]

The intercity rail energy stats published by the DOE, including ridership, come directly from Amtrak. Many, if not most formal van pools use 12 passenger vans, so a count of 6.1 per van is only 50% occupancy.

The DOE report has a pretty comprehensive discussion of the basis for ridership figures and assumptions. The figures are not just pulled out of thin air.

 

[jis]

The intercity rail energy stats published by the DOE, including ridership, come directly from Amtrak. Many, if not most formal van pools use 12 passenger vans, so a count of 6.1 per van is only 50% occupancy.

The DOE report has a pretty comprehensive discussion of the basis for ridership figures and assumptions. The figures are not just pulled out of thin air.

I specifically said that I completely believe that they were based on concrete data. All that I said is they are not particularly useful for planning a specific system since the range of systems from which data was rolled up for it made it somewhat useless for the purposes of planning a specific system, or even coming to any conclusion on how future policy execution would change these parameters.

In the same spirit, Amtrak system-wide data is not particularly useful in determining what the energy consumption profile is for NEC for example.

Your point about 12 seat van is well taken.

BTW there are some obvious factors that weigh in against American passenger trains being as energy efficient as those elsewhere. For example, American trains tend to have some of the lowest seat densities and some of the highest tare weight per seat that has to be carted around, of any trains in the world. That has negative impact on energy efficiency.

 

[andrew]

how far can a train go on fuel? like how many times would the locomotives on the Sunset Limited or Empire Builder need a fill up?

 

[BCL]

how far can a train go on fuel? like how many times would the locomotives on the Sunset Limited or Empire Builder need a fill up?

A P42DC has a 2200 gallon tank. I'm guessing that both segments of the Empire Builder can go the entire route without refueling. I think the California Zephyr or Texas Eagle are longer and won't require a fuel stop.

As far as the fuel goes, I thought it was No. 2 fuel oil. Someone told me that it's practically identical to No. 2 diesel except for the addition of a red dye to indicate that it wasn't taxed as a road fuel. The dye is supposed to indicate that it was used illegally if found in an over the road truck.

 

[Paulus]

Amtrak's diesel trains average 2.3 gallons per mile.

 

[CCC1007]

I know that Amtrak refuels in havre, mt.

 

[KmH]

Yep. That's why each P42DC locomotive has 2200 gallon fuel tanks.

So a P42 goes less then half a mile on a gallon of diesel fuel?? WOW! That's crazy on how short of a distance it goes. I would think at least two miles. I was wrong.

It has 16 cylinders or maybe 12 and each cylinder is the size of maybe a washing machine just a guess

The P42DC prime mover engine has a V configuration diesel with 16 cylinders and each cylinder has a displacement of 10.95 liters (668 cu in). Total displacement is 175.2 liters (10,690 cu in.).

I think the CZ refuels in Denver going each way, and start full at each end of the route.

Don't forget that some of the fuel used goes to making Head End Power (HEP) of up to 800 Kw of electrical power for the train.
Traction motor HP is decreased as more HEP is produced.

All Genesis engines can provide head-end power (HEP) to the train drawn from an alternator or inverter powered by the main engine at a maximum rating of 800 kilowatts (1,100 hp), making each unit capable of providing HEP for up to 16 Superliner railcars. The P40DC and P42DC power plants can supply 60-hertz head-end power either from the HEP alternator with the engine speed-locked to 900 rpm (normal mode) or from the traction alternator with the engine speed-locked to 720 rpm (standby mode). In the latter case, traction power is unavailable.

 

[VentureForth]

Southwest Chief refuels in ABQ.

 

[CCC1007]

The numbers indicate just under 1000 miles for their range.

 

[DryCreek]

But how many MPGs does it get on 89 octane unleaded gas?

Zero. Putting 89 Unleaded into a P42 would create damage to its valve gear and fuel delivery systems, not to mention its block, pistons, etc. that would cost, I would guess, hundreds of thousands of dollars to fix. You would, in all likelyhood, need to replace the entire prime mover.

Actually, no. Diesel engines run on compression-ignition fuels which and are rated in cetane numbers, whereas spark-ignition fuels are rated in octane. I live where diesel engines are very popular, and we own two diesel pickups and two diesel tractors. I have seen what happens when an unwitting person fills their tank with gasoline instead of diesel. The engine just stops. Lighter distillates won't combust in a standard compression ignition engine*. What we've had to do to fix the problem of wrong fuel is simple - you siphon out as much of the gasoline as you can, and refill the tank with diesel, and maybe throw in a gallon or two of TC-3 two stroke oil to slick up the injection pump internals. In most cases, the lack of lubricity in the gasoline isn't a problem as the engine doesn't run long enough to screw up the lift pumps, the injectors or the injection pump.

* there are/were hybrids known as "Distillate Engines" that ran on both fuels, albeit not very efficiently.