This is another coal mining method. It is not greatly preferred over different methods because certain parts of the coal is left in place to support the roof from collapsing. 

 

Process-

Think of this method like a grid. This is a relatively simple idea, which repeats itself. A rectangular area is carved out. Roof bolting is done with a machine which is called a roof bolter. These machines are used to install a sort of "bolts" to help support the layers of rock above the mining area. Shuttle cars are used to remove the materials through conveyer-belt system.