Discussion in 'Getting Started' started by steamhead, May 30, 2008.
Statistics are no substitute for mathematical formulations of
research result ratios.
Then of it's an average - that shows they are taking thousands of miles of operation into account and coming up with the "average"
by the way - you guys have ruined this for me forever
Next time I'm at a grade crossing, I'll be cussing (as always) that I dont't have the camera...
....and thinking of THIS THREAD!!!!!!!!! :rofl::rofl::rofl:
Seems a waste for the 100th post, but before the train can get where it's going it has to get half-way there, then half-of the next half. It will never actually arrive, right?
Jason...This was the dilemma that lead the ancient Greeks to develop the concept of the atom...They saw that this argument was patently false, since it was obvious that everyone got to where they were going. So they came up with the idea that at some point, you came to an undivisible piece of something, which allowed you to cross the "finish line", so to speak. They called this something an "atom".
Some people wrongly claim that the Greeks "discovered" the atom (as we know them today). They were in fact coming up with a reason why people did get to where they wanted to go.....
And they didn't need no "tons per gallons" either....:mrgreen:
Zeno of Elea wasn't thinking straight.
Before you can get to somewhere, you have to be elsewhere,
and if you're elsewhere, you are for sure going to miss your train,
so you can never arrive, q.e.d.wall1wall1wall1
Steamhead.....something is wrong with either me or you,....you're starting to make sense.
Lynn...I'm sure it's not you....
Josh, the ruling grade on the Cajon Pass is actually 2.5% on one track and 3% on the other. I'm not sure what the 3rd track that was built by the SP has for a ruling grade. The main reason that they do "left hand running" on Cajon is to use the 3% for the up grade and the 2.5% for the down grade to avoid runaways.
Hello, All. I can't completely wrap my head around the theory of all of this, but ran intermodal trains on NS from Pittsburgh (Conway Yard) to Harrisburg on the Pittsburgh Line (ex-CR/PC/PRR). In another discussion (on another Forum), calculated from personal observation that a 3000ton train hauled by two 4000hp locomotives used approximately 2000 gallons of fuel (total for both engines) over the 250 mile route over the Allegheny Mountains. Intermodal trains are allowed 60mph max (where not reduced by curves or other restrictions), similar speed to highway trucks, for a total running time (with CLEAR signals) around 7:30. That's 3000 x 250 = 750,000 ton/miles / 2000 gal. = 375 ton/miles per gallon...and these are HEMI CHARGERs, compared to normal trains (ie. Time trumps Economy). I don't find it difficult to believe that more conservative operation might return the figure claimed by CSX... and all those truckloads handled with only TWO crewpersons (?), with coffee stops or FLAT TIRES. It's not a scientific sample, just observation - I've proved myself wrong before !!! Bob C.
OK.....Now it makes sense....
It'd take approx 2000 gal. to go 375 miles, which is +/- 5.3 gal./mile, whether they were running "light" or hauling 3000 tons behind them. So the "total" calculation, which includes tons, does kinda work out....!!!! Thanks Bob. I was sure someone out there had the explanation for this. :thumb:
Never ever ever start a diesel powered train on Notch 8- now that is a waste of fuel! Start on Notch 1 so that you can "pick up the load".
(Reply to another post I read earlier which is now of topic kinda- sorry!)
Everything discussed shows the efficiency of scale, a train can carry alot of stuff long distances cheaply. Trucks do a great job carrying stuff short distances or to remote locations effectively. The trend is returning to trains for long haul and trucks for short. I recently read where Norfolk Southern and a bunch of shortlines in NY/PA signed an agreement to work together better to provide a shortline trucking service with their trains. Time will tell if it works.
Well, not quite. They are going to burn a lot less fuel with nothing behind them, but they won't get much moved! There will be a point where the ton-miles/gallon peaks, I would think the railroads try to run at that point, as much as possible. Less load, and they are less efficient, and more load, they are less efficient.
I understand that "light" running would consume less fuel, but then it would be pointless for them to do so....
Light running was one of the reasons that mallets were used. Having to pay for the the coal to move an extra engine over 30miles light...and then actual help for only 5 miles...not to mention crew costs...led to the deployment of mallets. All three of the major Colorado narrow gauges had mallet plans...and discussed ordering them (the C&S looked into 2-6-6-2s, the RGS 2-8-8-2s, and the D&RGW 2-8-8-2s). The C&S calculated a huge savings in fuel.
Something that people miss is that every motor has an efficiency curve. My small car gets very poor gas mileage at 80mph. It also gets very poor mileage while idling. One of the most impressive things about the USAF's new F-22s is that while most fighters are only efficient around 250-400mph...its engines are efficient at more than 1000mph...allowing it to easily outrun other planes with higher "top" speeds.
Josh mentions the I15, so I presume the steeper grades he refers to is on the highway itself, not the rail lines.
Regarding the efficiency of locomotives moving large amounts of weight over long distances, it's definetly possibly as a result of economy of scale; the Class 1's have been making a major push over the past several years to get to these levels - the obvious face is new, more fuel efficient locomotive design, but that's actually only a small part of the equation (since so many older units are still in use); there has been a greater focus on operations efficiency and infrastructure upgrades (double-tracking of lines, new signal systems, etc.) allowing more 'wide-open' running and less idling on sidings, which goes a long way to increasing average fuel to freight-miles consuption. Just like a car and highway mileage, keeping a moving train at an efficient crusing speed uses a lot less fuel than getting up to speed.
As a parallel, think of your home's AC system - wherever you keep your thermostat set, say 76, I've read (no, I don't have proof), that it uses less energy to leave the AC on while your gone in the daytime and maintain the temperature, than it is to turn it off in the morning, let the house warm up all day, then turn it on when you get home in the afternoon and have to cool the house back down again.
All vehicles, land, sea or air, acheive 0.00 mpg when stationary.
In fact, if you roll back on a slope you can actually get negative mpg for that short time.
When a vehicle moves from 0 to 1 mph it used more fuel than in going from 1 to 2 mph. There's a thing called stiction, which most London cab drivers are aware of - they anticipate and slow, rather than stop at, say, red lights ahead.
Road traffic planners constantly overlook the 0mpg aspect of stationary traffic. Traffic signals are rarely synchronised, even within small zones.
Traffic movements on railroads are highly synchronised, hence massive fuel savings relative to stop-go working.
edit - fule savings? Did I write 'fule'?
It's true, your car uses less fuel at 4000 Revs than at 2500 Revs for eg.
OK, it's a month later and this shows up - maybe some clarification on how they got the figure. http://www.factcheck.org/askfactcheck/can_a_freight_train_really_move_a.html ...it's a lot simpler than I was thinking . Bob C.
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