Came across these pics on a Flickr site showing some wonderful scenes if this line in 1979/80. I was thrilled to see views of the sidings of Black Lake coal depot as i have never seen these before.
https://www.flickr.com/photos/railway_images/9128914345/in/photostream
https://www.flickr.com/photos/railway_images/9128914345/in/photostream