On a flat straight section of track, with the brakes off, how much tractive effort would it take to move one loaded freight car?
One (1) personpower (a fractional form of one horsepower). See this tool:
Only $150! 22 pounds and 70" long (Handle not shown in this view)
http://advancecarmover.thomasnet.com/item/railroad-car-movers/badger-249-railcar-mover/item-1002?
Theoretically, without tools, you could do it yourself.
Yeah, but then you wouldn’t have those darned shiny things to argue and fawn over.
Then there is this old, but well shown photo of some three secretaries (in high heel shoes) pulling the ALCO-built 4-8-4 for Timken #1111 ( Bearings demo) Locomotive called the Four Aces in
from this Thread @ http://cs.trains.com/TRCCS/forums/p/185153/2027566.aspx
posted by BaltACD. [On the above linked thread.]
[If you are curious about the history of this engine.]
We called the pinchbars in this neck of the woods, we used them to move boxcars of ice when icing passenger trains, am I dating myself?- - - - from the ice gang in Moose Jaw.
Let’s also assume roller bearings, no wind, and slow speeds. Also, solid track (heavy welded rail, good ties, well-tamped clean ballast, etc.) so that its vertical deflection under load is minimal, and the car does not have to roll ‘uphill’ even that little bit. On that basis, I’d use about 0.2% of the car’s weight (same as a 0.2% grade, or 0.2 ft. = almost 2-1/2" in 100 ft. of distance).
For a standard 286,000 lb. (143 tons) railcar x 0.2% would be 572 lbs. of tractive effort needed - plus or minus, say, 200 to 300 lbs. !
In the old days of friction bearings, 0.3% was a commonly accepted figure. I’ve seen claims of as low as 0.1% for the modern cars, and that could well be true in some ‘ideal’ cases. As the saying goes, “Your mileage - tractive effort - may vary.” In reality, there’s so much else that affects the tractive effort actually needed to a much greater degree - mostly grade, but also curvature, wind, soft track, etc. - that the ‘pure’ internal friction of the car’s wheels on the rails is likely the smallest and most insignificant portion, as well as one of the hardest to predict.
- Paul North.
At least two different questions here–
What does it take to start the car rolling? Or,
How many pounds will keep the car rolling at, say, 10 mph, once we’ve somehow reached that speed?
In friction-bearing days there was a big difference between the two; none of us has much idea how much difference there is between them now. Will a fully-loaded 140-ton car start rolling if we release the brake and it’s sitting on a 0.1% grade? Or do we need 0.2%? None of us has a clue.
But far as anyone knows the car will eventually accelerate to 20-30 mph? on a 0.2% downgrade.
By the way: don’t pay any attention to pictures of gals pulling 4-8-4s. None of us knows whether they’re pulling it downgrade (unless someone has pics of them pulling it forward, and then plodding to the other end and pulling the same engine backwards).
I know with absolute certainty that two people can move an empty coal car because I was one of the people. [:D]
I have seen one of these devices used at the FS (Farmers’ Service) building in my hometown Toluca IL, to move hopper cars (loaded mainly with potash from Canada) so that the hoppers were over the small opening to the underground auger they had installed. Eventually they just nailed plywood over the ties and used a forklift-style front endloader to move the cars (the building was made out of a cement siding impregnated with asbestos and had to be demolished and hauled away to a landfill in the 90’s).
Regarding human power, I used to watch ICG trainmen move empty covered hopper cars by hand in the Bloomington IL yard, a testament to the inherent efficiency of steel wheel on rail transport. Let’s see someone move a