longwall mining




ventilation - pre-cutting



Miscellaneous - Pre-cutting

In thick seams where coal is prone to fall from the face in large slabs, these can cause problems in that:

  • they can bridge across the AFC and need to be broken before they are carried away

  • they can create a hazard if they protrude out of the AFC into the chock area where personnel are located

  • in part they can fall into the chock area and damage personnel, hosing, cabling and apparatus

  • they can jam under the shearer or at the maingate/BSL transfer and cause a blockage and spillage.

Shearer fitted with pre-cutting section on drum To prevent this some thick seam shearer drums are fitted with an extension of the centre of the drum which cuts a small section out of the next web as a web is being cut. Any potential slab is thereby pre-cut and will fall in smaller sections than would otherwise be the case.