Drilling jumboFrom Wikipedia, the free encyclopedia A Drilling jumbo or drill jumbo is a rock drilling machine. This article does not cite any sources. (March 2015) An Epiroc Boomer historical 6-armed air-powered drilling jumbo on rails small 2-armed air-powered drilling jumbo
A Drilling jumbo or drill jumbo is a rock drilling machine. This article does not cite any sources. (March 2015) An Epiroc Boomer historical 6-armed air-powered drilling jumbo on rails small 2-armed air-powered drilling jumbo