How are trains able to start with so much cargo?

1.27K viewsEngineeringOther

Just passed by a train with a hundred or so cargo crates. how do they start? I understand how they continue moving, but how do they overcome the inertia of starting it? It has to be like thousands of tons, and I can’t imagine a bunch of coal being able to start moving that. unless of course it can, in which ELI5

In: Engineering

20 Answers

Anonymous 0 Comments

They gotta compress the whole train so all the cars are bumper to bumper. Then the locomotive(s) can start pulling, always just taking one car from standing to moving, which pulls the next car. The resistance is a lot less on already moving cars so when the entire train is moving, they can start accelerating properly. [On very long trains this makes for a giant “shockwave” travelling down the train when they start or brake](https://www.youtube.com/watch?v=7Anj8A6zgL4)

Edit: apparently it’s an outmoded practice for underpowered trains and modern locomotives have enough power to just start the entire mile long thing all at once.

You are viewing 1 out of 20 answers, click here to view all answers.