As usual, there are many varied items in this publication. What caught my eye was the section on "Developments at Bersham Tip", with the thread on this subject currently running on the forum. It was a working from this mine that caused the original subsidence under Erddig Hall, which is now a National Trust property. If you ever visit this, on the passageway that runs along the servants working rooms, there is a historical painted documentary map showing all the railway workings, both passenger and industrial, in the area.
There is a good 8pp pdf to download from that section of the publication on Bersham Colliery and its associated machinery and some rail-related information.
I love the place, so steeped in history, I was lucky enough to have a tour of the cup & Saucer underground working, the ex Estates Manager was a friend of mine http://www.flickr.com/photos/andy_mcr/488739894/ which explains how the the ram works,