Underground Mining Machinery Single Arm Rock Drilling Rig for Hydropower Water Tunnel Excavation. Ultra-Small Turning Radius: 2,397 / 4,280 mm enables navigation through 2.5 m narrow tunnels. Intelligent Safety Protection: Integrated leakage, overload, and short-circuit protection compliant with China Stage IV. Compact Design for Tunnels: Designed for narrow lanes and tunnels in metal mines and underground projects. Reliable International Components: Uses Cummins, Deutz, Perkins engines and Rexroth, Parker, Eaton hydraulics. Comprehensive Customization: Customizable engine brands, hydraulic systems, boom design, color, and logo.