longwall mining, Tag

The development of longwall coal mining took a significant step forward with the development of the armored face conveyor (AFC) and the self-advancing supports of both chock and shield designs that I described last time...

In the last post on this subject, I wrote about how miners were able to remove almost all the coal from a section, either by leaving small remnant pillars or building packs to hold the roof in place, while that coal was removed...