Jinke JK860 Crawler DTH Drilling Rig for Hard Rock Water Wells Hard rock water wells are a different job from drilling in soil: you need a DTH hammer, enough air, and a rig that can move between boreholes without a truck and crane crew. The JK860 crawler does exactly that. It drills 115-178mm holes and walks itself around the site on steel tracks. Main Specifications Drilling Method Down-The-Hole (DTH) Hole Diameter 115-178mm Engine 132kW / 180HP diesel Rotation Torque 3500