Question: How are locomotives able to pull such long trains? Triple 777 pulls a 39 car train, which can weigh thousands of tons when the cars are loaded.
Ssiscool
4th May 2019
Unstoppable (2010)
Answer: Locomotives are heavy. The heavier a locomotive, the more traction it has, and then it can pull more weight.
Answer: In the same way locomotives pull long trains in real life. Diesel engines are built to pull the weight. When it gets to a certain point you might need 2 engines.
Ssiscool ★
OK but what is the physics behind how locomotives are able to pull so much weight?
I'm not sure on the physics but a quick Google search comes up with: Trains are really heavy, but to move a train, you only have to overcome the friction between the wheels and the [axles]*. But since there are wheels, it's even easier to move it. Imagine a really heavy box. You'd have a very hard time lifting it, but you could shove it a few millimeters horizontally. [But instead of shoving it, you can make it roll!]* The same thing applies to a train. Now, since the train is so heavy, it takes a long time to get it moving, and to slow it down, due to [inertia].
Ssiscool ★
I'm not sure of the physics, either, but it is my (basic) understanding that having the wheels as well as the rails made of steel minimizes? the friction. [Living in the suburbs of the "Steel City" helped to know this!] I'd clarify your answer above by pointing out a train is comprised of numerous small cars - as opposed to being one very long car - so is somewhat easier to "get moving."
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