Isambard
Grizzly Northern history, Tales from the Grizzly and news on line at isambard5935.blogspot.com
QUOTE: Originally posted by wccobb May we regress to the theoretical laboratory of high school physics? "Tractive Effort" is force. It has no dimension in time, it has no dimension in distance. Suppose you stand on your own two feet and push against a boxcar. You're devceloping a force (tractive effort). If the boxcar doesn't move, that's all you've done. But your tired muscles and aching feet tell you that you've developed tractive effort. If the boxcar moves, there is force (your pushing), the distance the car moved and the time it took you to move the boxcar. These are the three factors which constitute power. SO -- the "laboratory" answer is that tractive effort is independent of power, but power is composed of force (tractive effort), distance and time. There's another usage for these terms in the railroad business. "Tractive Effort" is a term from some 100 years ago. It told management how many cars (tonnage) a steam locomotive could "bust loose", drag out of the yard and haul down the track. Time and speed didn't matter. One hundred miles was the day's pay for the crew. If the crew averaged only 8 mph they'd still get over the road before the hog law caught them. Each additional car was more profit for the railroad. And "horsepower" was something for the "slide rule buys" to play with. Today the railroads make money by moving "stuff", frequently at "track speed". Speed takes "Horsepower". Today's trains are dispatched with a very rigid ratio of lcomotive horsepower to train weight. And only the railfans pay much attention to tractive effort.
USAF TSgt C-17 Aircraft Maintenance Flying Crew Chief & Flightline Avionics Craftsman
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QUOTE: Originally posted by edblysard I think all of you guys should buckle on your pocket protectors, whip out your slide rules and HP calculators, and face off. First one that can devise a working real time model/example of Einstein"s theory of relativity wins a trip to Disneyland... Oh, and the SD40 can move more train, but the GP40 can kick cars better and faster... Ed[:D]
QUOTE: Originally posted by Isambard QUOTE: Originally posted by edblysard I think all of you guys should buckle on your pocket protectors, whip out your slide rules and HP calculators, and face off. First one that can devise a working real time model/example of Einstein"s theory of relativity wins a trip to Disneyland... Oh, and the SD40 can move more train, but the GP40 can kick cars better and faster... Ed[:D]
Quentin
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