Professional Answer: Sag and tension diagrams are vital for the mechanical design and safety of overhead transmission lines. Sag refers to the downward dip of the conductor between two support towers, while tension is the pulling force on the conductor. These diagrams help engineers calculate the correct sag for different temperatures and weather conditions (e.g., wind and ice loads). Incorrect sag and tension can lead to conductors touching the ground, short circuits, or structural failure of the towers. Our tension stringing equipment is specifically designed to manage these critical factors during installation, ensuring optimal sag and tension for the life of the line.