Nerd time. Hump yards or hump shunting is when they push a rail wagon down a hill and use gravity to push it.

Then there are a bunch of switches to go through to make it go into a particular road.

It then runs into whatever wagon was already there (and automatically couples together).

This impact is very bad for wagon mounted equipment and sensitive cargo.

I hate hump shunting. So I agree with this post. DO NOT HUMP.