A heavy-duty steel hydraulic drilling mast designed for trailer-mounted water well and geotechnical drilling rigs. The mast features a chain-driven feed system, hydraulic lift cylinder, high-torque top rotary head, integrated hose routing, and a rigid guide rail for smooth drilling operations. It is engineered to provide high lifting force, precise drill pipe handling, and reliable performance in medium to hard rock drilling applications. The compact design makes it suitable for mobile drilling rigs while maintaining excellent structural strength and stability.