Roel - The trains that run to the north west mines are typically rakes of 72 wagons, either the 120t (gross) type seen above (with modern AC traction and ECP braking), or older 100t (gross) wagons with older DC traction and normal air brakes. Here's a shot of the same train a day earlier, which shows the whole train:
http://www.flickr.com/photos/raichase/6779992575/in/photostream..tbox/
It takes something like 20 hours for a full round trip between the mine and the unloader, including loading/unloading time. Monster trains they are!