Considering the pillar (rock) stress problems and the constant liberation of large amounts of flammable methane gas in the development sections, MCR decided to convert totally to an advancing longwall system.
Because the same conditions were encountered earlier in the B-Bed, MCR had had one advancing longwall operational in the B-Bed since 1976.
A roof fall on the start line created some initial problems, but MCR soon brought the first advancing longwall on-line in the M-Bed, 211 LW.
An advancing longwall system has advantages and disadvantages.
MCR had an advancing longwall on-line, but they had no way to support the gates.
For the last 10 years, falling coal prices, tougher-conditions underground, and demands for increased production forced MCR into choosing a unique mining method, advancing longwalls.