Back holes | Article about back holes by The Free Dictionary
back holes[′bak ‚hōlz]
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.