Consolidated in this book is a simple means of setting down large mining arrays over ore patches and sending them off to a depot.
If you like me, are a big fan of managing and organising of your rail network then look no further. Here we have a very simple train to train transfer depot. There is a holding of 25 trains for both the offloading and loading trains. It's currently set up to offload 2 trains onto 1 but is easily reversible, depending on your need.
I personally use a depot to consolidate resources like ore into one place to be dispersed across the rail world and its factories rather than having trains running all over the place.
If your not a fan of simple builds then check out my post for a far larger and absurd depot: https://factorioprints.com/view/-LcboPjuti_2if4hak1a