Discussion in 'Getting Started' started by steamhead, May 30, 2008.
how it is that RR's can move 1 ton of freight over 423 miles on one gallon of fuel....:cry:
They don't. I may be wrong, but if they tried to move just 1 ton of freight on a gallon of fuel, they would not get nearly that far. The economy is in the volume. If they move enough tonnage it takes less fuel per ton per mile to move it. The key factor is that steel wheels running on steel rails is one of the most efficient ways to move anything. In comparison, think about the amount of traction you get out of a set of rubber tires. All of that traction is friction making it difficult to move your car. It also eats up power and uses fuel like crazy in comparison. I think the other factor that helps fuel economy is the momentum inherent in a moving train. I was told once that the Santa Fe tested how fast a train could stop by doing an emergency stop while going UP Cajon Pass. It took the train 1 mile to stop from 20mph while going up hill. Also, once the train gets up to speed on a level stretch, they can throttle back and kind of coast to keep the load moving. In other words, they may need to be in "run-8" to get the train moving, but once up to speed, they can probably go back to "run 5" to keep it moving. I don't know the numbers for sure, someone like Brakie, probably knows a lot more than I do. I guess another way to explain it is that the train acts like a 100,000 ton flywheel to keep everything moving once it gets going.
They do... Its simple math. Its no were near perfect, but its a yearly total gallons burned to miles traveled, to tons hauled...
Oh, of note, CSX does not say trains move the ton of cargo, ect... This is a quote:
Welcome to CSX.com: Customers - Carbon Calculator
Momentum matters. Back in the days of steam an engineer and fireman who shall remain nameless (freinds of the family) fell asleep on a trip from Pennsylvania to Baltimore after midnight.When they woke up the train was in Baltimore, 40 miles from where they started with the fire completely out. The train had traveled most of the distance using no fuel, and the starting point was thehighest point on the line. Lucky for them they were the only train on the line at that time of the night.
They also use only about 1 to 1.5 hp to move each ton, and they do it (relatively) slowly. All that increases the efficiency rating. Think about that next time you take your 250hp, 1.5 ton car from 0 to 60 in record time...!
Also, consider than on average, railroads consume 10% of the fuel per ton-mile that heavy trucks do. So if a truck could take 1 ton 42 miles on a gallon of diesel, the RR can move it 10x as far - 420 miles.
another added theory is that trains do stop... but nowhere near as often as trucks do - especially in urban areas.. as a matter of fact, i always see a truck "stopped" at our railroad crossings... while the trains move merrily along.
Also, that "starting and braking' from each of those "stops" uses fuel too....
The proof here is that UPS actually routes trucks so they encounter right turns, so they minimize their "stops and starts"
Turn right, save gas | Latest News | WFAA.com
It's all downhill from here..
Another part of the equation is how flat railroads are.
Most operate on less than 2% grades.
At home and at work, there are steep ramps in and out of the underground parking lots. Somewhere in the neighbourhood of 35% to 40% grades.
I'm sure that many roads and highways have stretches of 10% or 15% grades.
It takes a lot of juice to get automobiles up and down all those hills.
Actually, they're not quite that bad. I suppose you might see a 30% grade,in a lot, but I rather doubt it.
The maximum grade allowed on US Interstates is 6% in hilly or mountainous areas. Oregon DOT says the 6.4% grades on I5 through Siskiyou Pass are some of the steepest in the nation. But that grade only lasts for a little over 6 miles of the 300 mile route.
You might find the occasional grade pushing close to 10% on a secondary road, but they'd be rare.
On the Trans-Labrador highway (basically a wide dirt road pushed through the wilderness), I came across only one serious grade - 15%, and that was only for a kilometer.
Obviously if they're _only_ trying to move a single ton of freight that doesn't work, but consider that a train can move several thousand tons of cargo several hundred miles on a few thousand gallons of fuel. Take the total amount of fuel, divided by the tonnage moved, and that gets you an average of how much fuel used per ton for the distance travelled. Then divide out that ratio to get a 1 gallon/ 1 ton /x miles figure.
Cajon pass on the I15 hits 7% uphill, 8% down.
Ok....Let's say we take the ideal diesel ( dash whatever), fill it up with a gallon of diesel....and let her rip...How far will it go..?? Not 423 miles...that's for sure...and it doesn't even have a gram of load...!!! If we attach a ton load to it...it will go even less than unloaded. So where's the catch..??
Try attaching a few thousand tons to that loco. Remember, the loco itself weighs around 200 tons, and it has to move that weight as well.
If you take said locomotive, put a gallon of fuel in it, I believe it would in all probability run out of fuel before it got hooked up and moved anything. If one was to put that same gallon of fuel in a tractor, that tractor would be able to move freight at least some. Now aqccording to Aristotle, Plato, and Archemides, an apple falling would have nothing to do with moving freight. So, that means a tractor is much more capable of moving freight, as long as it is apples.
I'm surprised how difficult a concept this seems to be.
It's not based on "put a single gallon of fuel in and see what happens."
Fill up the tanks on the locomotive and tractor. Give them both some stuff to pull. The locomotive will pull a heck of a lot more a lot farther, and even when you divide the numbers by the different amounts of fuel used, the locomotive will have moved more ton-miles per gallon of fuel than the tractor.
(And it's "up to" 420 ton-miles/gallon, so that's the statistic best case.)
That's like some Major department Stores around these parts have "Register Roulette" around Christmas....
You scratch off a "slot machine" type card at the register.. to get up to 50% off your entire order....
It's really cool!! Brings a LOT of business in.... but everyone that plays seems to get 5%, 10%, 15%, or 20%..... wall1wall1
What..... No 50%?!?!?!?!?!?
Yeah - by LAW you MUST not false advertise... so they toss in 20 or so 50% off cards out of the thousands they print....... "up to" is an evil reference.. and a great advertising protection.. We SAID up to!! not ALWAYS!!!! :curse::curse::curse::curse:
So....the general consensus is that the greater the load, the more efficient the locomotive..?? That doesn't make sense, as any system's efficency degrades with greater demands made of it....
(I'm playing the devil's advocate here....). :twisted:
sign1sign1sign1That's SICK!!!! sign1sign1 i never thought of it that way
It's a curve on a grade... The trick (Enginneer's job) to make sure the "efficiency" doesn't go below a certain percentage, that is to say that the locomotive should run smoothly, and at a near constant speed, no matter how many fulls or empties are behind her.
Therefore, it could be said that it doesnt matter what the locomotive is pulling, over the same 5 miles of track, at the same time of day, at the same temperature and humidity (Temp & humidity effect air intake and cooling) the locomotive should use the exact same amount of fuel on avreage
That's where they get us with car mileage MPG.... it's NEVER right.. it's NEVER the same.. and it is so deceiving....
A 35 MPG car should get 35 MPG, but that's an average of hundreds of miles of driving in a controlled situation.. For instance Highway and city... As soon as you "mix" the 2 - the mileage will go down just a mile or 2
City driving will always depend on how many stops you make, how long you stop with the engine running and how many times you stop and restart the engine.
So... To transfer this to the locomotive, this was probably done in a testing atmosphere - over 4 or 5 - maybe even 10 tanks full of fuel.. and they got 20 or 30 "Ton/MPG" readings... When they averaged them together.. they were probably around 410 tons/MPG
But the BEST run was 420.. That's the bragging rights!! In order for them to state it anywhere - they Must have the documentation readily available for any potential questions as to the authenticity... The Consumer Protection Agency and the Free Trade Act say so!!
Did someone mention 'devil's advocate?
For sheer efficiency, comparing load with load, you can't beat steam.
In 1878 the reported efficiency of the A1 'terrier' class 0-6-0 was 20.15 lbs of coal burned per mile run. This would be: pulling 6 units of 4-wheel coaches, each about 30ft long.
First built in 1872, several of these are still working on heritage railways.
LB&SCR A1 class - Wikipedia, the free encyclopedia
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