longwall

plural longwalls

1. attributiveoftenbusinessA long wall of coal that is mined in a single slice.

   1 more example

   In addition to its work on longwall faces, the A.B. Fifteen has been adapted for shortwall work either as undercutter or as overcutter, particular care having been taken to give it increased manoauvrability by the provision of special pulleys, and increased mobility by the addition of a tilting underframe.

   1960, Colliery Guardian Overseas, page 50