Underground core drilling rigs are compact, explosion-proof devices designed for narrow mine roadways to obtain rock and ore samples, classified by chassis, power, drive and drilling depth. In terms of mobility: Mini split portable rigs are disassembled and carried manually into narrow tunnels. Small crawler-mounted units feature slim rubber tracks for flexible movement inside mines. Rail-mounted models slide along mine tracks for fixed long-distance drilling. Power sources differ for safety: Diesel hydraulic types suit well-ventilated tunnels. Electric hydraulic rigs produce no exhaust, widely used in these enclosed projects. Pneumatic explosion-proof rigs are standard for gassy coal mines to eliminate fire risks. By drive structure: Spindle hydraulic rigs work for shallow short holes. Selecting a high-performance underground core drilling rig with a compact top-drive power head ensures stable torque and supports wireline coring for deeper exploration. Classified by depth: Light rigs drill within 100m for roadway advance detection; medium rigs reach 100–400m for ore body delineation; heavy underground core drilling rigs achieve over 400m deep coring. Most match triple-tube barrels to keep fractured ore cores intact.