back holes

back holes

[′bak ‚hōlz]
(mining engineering)
The holes which are shot last in mine shaft sinking.
References in periodicals archive ?
want to People for a crease area land stand to to back holes Both then then rolled.
For a wider action on a slower pull, attach the snap to one of the back holes.
RNRC0016 and 29 are forward and back holes to RNRC0017 and RNRC0003 respectively.