At what capacity is a passenger train environmently friendly?

One of the arguements on the “Republican Sweep” thread for keeping Amtrak is the environmentally friendly nature of passenger rail. This is a broad statement. It seems a train with 50 passengers would not be better for the environment than the 20 to 30 automobiles used if the people drove to their destinations. This would probably hold true for 100 to 150 passengers as well.

I love riding Amtrak, but its passenger volume is less than 1% of the total intercity passenger miles of all travel. This volume could easily be absorbed by other modes of travel with only slight capacity increases.

So if “friendly to the environment” is the arguement for keeping Amtrak, at what passenger count is an Amtrak train truely environmentally friendly?

The Metra F40’s used about 125 gallons per hour when operating with train lights on. During non-rush hour, trains operate with as few coaches as possible; but due to track capacity, switching times, etc, some off-peak trains operate with up to six coaches while using only one or two-the others are dead weight hauled around. So those are not efficient at all.

However, a ten-car rush hour train uses about the same amount of fuel, but carries about 2000 people. That train is incredibly fuel efficient.

So I suppose it depends on many factors as to when the efficiency comes in. Would the riders be driving Hummers or Hondas? Would they be driving non-congested open highways or in clogged urban roads?

Zardoz: Exactly how much of the specific fuel consumption is attributable to HEP? And are there accurate fuel-consumption measurements for loaded vs unloaded consumption during the different parts of a run (e.g, acceleration required for timekeeping)?

Likewise: how much more ‘efficient’ is a train using separate diesel gensets for HEP vs. ones with the various flavors of traction-alternator tap…

At least for VIA, we our train sizes varry day to day. The least is 3 coach cars but on occasion it has been as high as 11 coach cars. Sometimes a baggage car is added too. VIA pays CN money per axle so if they don’t get ex amount of advanced booking of tickets, they put on the minimum. They are pretty good about it too. Amtrak train that goes between Toronto and New York is always 4 coach cars and 1 diner whether it warrents that many cars or not. That is why I think Amtrak is in the financial problem they are in. Alot of the time, VIA won’t add more cars until it gets to Toronto. For example, I went to Toronto to go to Belleville and saw that a VIA train had just arrived with 3 coach cars. It was enroute to Windsor. A train backed up with 6 more coach cars and a baggage car after the lead engine uncoupled and moved onto another track. After the second unit and its consist coupled on to the original coachs, the lead engine coupled to the other engine, loaded up the cars with tons of people and away it went. My train actually was 4 LRCs with a P-42. Another train backed into our train and coupled onto it. The consist was P-42/ 4 LRC/ P-42/ 4 LRC. The one train was heading to Montreal and the back train (my train) was going to Ottawa. It went from Toronto to Kingston before splitting up and going their separate ways. This one way of conserving capacity and saving VIA’s money.

Overmod: I do not know the specifics.

The only reason we were informed (and learned by experience of how often we had to take on fuel, as these locomotives had only 1500 gallon fuel tanks), was so that we would be aware of the usage and did not run out of fuel enroute.

The old E8’s and F7’s (which had the seperate engine for HEP) had huge fuel tanks, so fuel usage was rarely a consideration, and as such we were never informed of their rates of consumption. And as most every unit is fueled during it’s Chicago layover, we (CNW’s Metra) never ran out of fuel enroute.

Regarding the usage rate for acceleration and load/empty, there is likely some average, as the shorter trains make more station stops, so start and stop more often but are lighter, whereas the longer (and heavier) trains made few station stops.

I’m sure somewhere in the deep, dark sacred halls of Metra there is data regarding fuel consumption rates. But apparently that knowledge was on a need-to-know basis only, and us engineers apparently were deemed as not needing to know.

That 125-gallon-per-hour figure might be a good place to start, since the F40s have engines that run at a constant speed.

For the sake of this argument, I’m assuming that a gallon of diesel fuel is as environmentally friendly as a gallon of gasoline. Don’t know which is really friendlier.

If you’re driving a car on an intercity run, and you get 30 miles per gallon while traveling at 60 m.p.h., you’re using two gallons per hour. If you have a total of four people in the car, your gallons-per-passenger-hour would be 0.5.

The intercity train powered by an F40, burning a steady 125 gallons per hour, would have to be hauling 250 passengers to match that. What’s that–about four coaches full?

In commute traffic, the same car is going to get nowhere near 30 mpg, but the same F40 will still burn 125 gph. The car will be lucky to get 1 gph, and will probably not have added passengers to make it more efficient. The commuter F40 can haul 125 passengers easily in one coach (they have a capacity of roughly 160). Those rush-hour trains can have ten or more cars behind one F40, so there’s no doubting the environmental friendliness of the commuter train over the car. Intercity is a tossup at best.

The F40 has been supplanted, at least in commuter service, by newer locomotives that boast greater fuel efficiency, at least according to the publicity. That would improve the railroad side even further.

zardoz,
No doubt about a full commuter train or full bus being more efficient than the needed # of automobiles to carry the same # of people on the highways. As you noted, off-peak trains and buses do degrade the overall efficiency of commuter rail and bus.

Amtrak’s efficiency (environmentally friendliness) is what I’m questioning. Using the 125 gallons per hour for a F40PH, an Amtrak train with 2 locomotives and 250 passengers would use 1 gph for each passenger. If these same 250 passengers used 125 automobiles (assuming most intercity rail travelers go with companions), instead of Amtrak, and averaged 60 mph with a vehicle averaging 20 mpg, the fuel consumption would be 1.5 gph for each auto passenger.

On the surface, Amtrak appears more efficient. However, consider the number of freight locos burning diesel while waiting in sidings for the passenger train. It does not take too many idling freights to eat into or totally eliminate the 1/2 gph per passenger advantage given above for Amtrak.

Jay

PS–CShaveRR–We were thinking the same thing at the same time. I didn’t read your post until mine had been posted.

Like most environmentaly friendly/environmentaly hostile arguments, this one is a lot more complicated than it appears on the surface.
First, one needs to analyse rather carefully what the alternative modes of transportation would be. Would the passengers otherwise be going by car? Or by air? Or by bus? Or, just possibly, not at all? It is much more likely that, for intercity travel, our hypothetical passenger would be travelling by air, not by car. By car, however, using Jay’s figures above and assuming that the train is full and carries 250 passengers, one can say, indeed, that the train would use 125 gallons per hour less than the cars. This advantage would be reduced by trains forced to wait, but that is a widely variable thing. However, even in Jay’s figures, there is an assumption which, at least in the northeast, is wildly incorrect: there is no way that one can average 60 mph, or even close to it, on any highway north or east of Washington, DC. 40 is more like it. And in reverse, the trains average a good bit better than 60 in these parts. Further, trains in this area do not need to depend on diesel. All of this tilts the scales strongly towards the trains.
Further, while emissions from gasoline engines and diesel engines are more or less comparable, it takes a good bit more crude oil to create a gallon of gasoline than it does of diesel – and a good bit more water, too. This must be factored in on the environmental side.
Another factor which might be overlooked in the northeast and far west is the impact of the automobile vs. the impact of trains in terms of infrastructure. Most highways in these areas are running at or near capacity – as are, frankly, most rail lines. However, adding capacity to a highway has a lot more environmental impact that adding capacity to a rail line. Not only are highways inherently less friendly than rail lines in terms of water quality (in my business we get to analyse water quality impacts from highways and rail lines, among other things.

FYI: the Metra commuter coaches have a seating capacity of about 175, with room for another 25 or so standing-room. The rush-hour trains are at capacity every morning and evening.

And how would that compare to a Greyhound bus that gets 6 miles to the gallon and carries 55 passengers and 6 standees

I don’t know for sure how VIA and CN work out the financing but from what I understand, VIA pays CN “rent money” for using their tracks and is billed per axle. VIA does not do indemnification. VIA does invest in the railroad’s capacity on the line they use if necessary. I believe (can’t confirm) that VIA (federal government) added track between Aldershot and Toronto as to reduce interfearence with traffic inbound and outbound from the Halton Subdivision (MacMillan Yard route).

It’s too bad really that Amtrak and the railroads in the U.S couldn’t have set up something like VIA. If I’m right with what I said, some of thease busy lines would have been upgraded and extra tracked curtosy of the feds. It’s also too bad that the U.S would likely not go for that for what ever reason that would prevent them from doing it to better their passenger services.

You also need to add the fuel consumption used in driving from one’s home to the rail station and back. A more accurate way of figuring “real” fuel consumption attributable to mass transit must include this segment of the commute. What is the total fuel consumption from home to office and back (not just station to station)?

A similar oversight is committed by the freight railroads when they trump the improved fuel savings attributable to use of unit trains. T

There is also to consider that those who drive to the station are usualy a short drive in the morning wich is the time when the automobile polutes the most because the car is started after the coldest time of the day and a cold running engines pollute alot more then a warm engines. But for those that walk to the station they help make rail transit more environmentaly freindly ((and get to breath everyone elses exhaust if walking on the sidewalk in the morning)).

Also to consider is empty return runs of commter trains even if there is 2000 people in the one direction there may be none the other direction.

If the train was electric and the source was an environmentaly sound low emision poower plant or some old bealching smokestack.

Another thing is that trains are generaly huge and require many passengers to operate efficient, but that realy does not need to be the case. Light rail deisel powered equipement with no more capacity then a bus should be able to role down the rail line very efficiently at a modedrate speed and consume very little fuel per trip.