... rotary drilling rig is a high-efficient piling machine applicable to the construction of bridge, railway, building and YTR/YTRD rotary drilling ... rig is a high-efficient piling machine applicable to the construction of ... cover YTR260, YTR230, YTR200, YTR160, rotary drilling rig, YTR220, YTR150, rotary drilling rig with domestically-made chassis, YTRD300, ...