Here are ways to improve productivity in underground coal mines. The suggestions are well documented in a seminal paper Roof bolting and mining: are your cycles in tune? By E.B. Kroeger and M. McGolden published in the January 2007 issue of Mining Engineering. Sadly you need to be a member to access the paper. You can access for nothing this paper by the same authors on pretty much the same topic: Increasing underground coal mine productivity through a training program.

The paper reports on work funded by the Illinois Clean Coal Institute. Here is a paper from their site that is related to the paper by Kroeger and McGolden and well worth reading: Development and Demonstration of alternative room-and-pillar mining geometry in Illinois by Chugh et al. Another related paper is Best practices and bolting machine innovations for roof screening by Robertson et al.

The paper by Kroeger and McGolden uses a mine model developed by Stan Suboleski. I cannot locate the model which is used in the report Development and demonstration of advanced mining technologies to reduce production cost by Chugh et al.

On the topic of roof bolts in coal mines, here are some additional resources:

Back to the paper by Kroeger and McGolden. Here is their conclusion:

There are many variables that have an affect on the productivity from an underground room-and-pillar coal mine. One of the goals of this paper was to illustrate the need for mines to model their production systems, including their roof-bolting cycles, an determine if further improvements can be made. Another goal was to help mining operations quantify the benefits of specific changes so they can make more informed decisions and focus their attention on the most critical issues. These critical issues can then be incorporated into a miner-productivity-training program to increase the productivity from the mine.

The work by the authors, their colleagues, and the related sponsor goes some way to achieving the goal of safer, more cost-effective mining. Pity that the tools needed to advance are not more freely available.