Tractive effort

Tractive effort is the strength that a train engine has to move the train. Imagine you are trying to push a really big box up a hill. If the box is really heavy, you will have a hard time pushing it up the hill because you need a lot of strength to move it. The same goes for a train engine. The engine needs to have enough strength to pull the heavy train behind it.

Now, when we talk about tractive effort, we are talking about how much strength the train engine has to move the train. It's kind of like the engine's "muscles." The stronger the engine's tractive effort, the easier it is for the engine to move the train.

But, there's more to it than that. Tractive effort also depends on the surface the train is on. Just like it's easier to push a box on a flat surface than up a hill, it's easier for a train engine to move the train on a smooth, flat track than it is on a bumpy, hilly track. This is because the engine has more friction (or grip) on a smooth track than on a bumpy one.

So, to sum it up: Tractive effort is like the strength or muscles of a train engine. It's how much force the engine can use to move the train, and it depends on how heavy the train is and how smooth the track is.