In the context of Overhead Transmission Line (OHTL) construction, a "Transmission Line Machine" primarily refers to the specialized, heavy-duty, powered equipment used for the precise installation of conductors (wires) and ground wires on transmission towers. The two core types of these machines are:

• Hydraulic Pullers: Designed to generate controlled pulling force to draw pilot ropes or actual conductors across spans.

• Hydraulic Tensioners: Engineered to apply continuous, controlled back tension to the conductor as it's being strung, preventing it from touching the ground and ensuring proper sag.

These machines are distinct from general construction equipment due to their specialized functions, emphasis on precise tension and speed control, and their role in protecting the conductor's integrity during the complex stringing process.