Straight-line towers: These are suspension-type straight-line towers in the load classification. They serve solely as support structures for suspending conductors and overhead ground wires in straight sections of the line, primarily bearing vertical and horizontal wind loads.
Tension towers: These are tension-type straight-line towers in the load classification. The conductor and overhead ground wire break at the tension tower, positioned within a straight (or angled) section of the line. They reduce the length of continuous spans along the longitudinal direction, facilitating line construction and maintenance, and controlling the potential for tower collapse along the longitudinal direction. In the event of an accident, they withstand the tension of the broken wire, preventing the accident from spreading to another tension section. Besides supporting the weight and wind force of the conductors and overhead ground wires, the tower also bears the tension of these wires.
Angle towers: Due to the influence of terrain features along the line's route, towers are erected at appropriate points where the line needs to be deflected in a suitable direction. These are used at line bends and must bear the lateral component of the conductor's load.
Terminal Towers: Terminal towers are the towers at the beginning or end of a line. Located at the start or end of the line, they connect power plants and substations and bear significant longitudinal loads. The conductors and overhead ground wires on one side of the line are directly tensioned on the terminal tower, while the other side is connected to the portal frame with very little tension.
Crossing Towers: Crossing towers are used to support conductors and overhead ground wires crossing rivers, lakes, and straits. They have high height and strength.
Transposition Towers: Towers used to change the arrangement of three-phase conductors in a line. When the conductors are not interrupted on the transposition tower, it is called a straight transposition tower; otherwise, it is called a tension or angle transposition tower.
Branching (Branching) Towers: Towers that decompose a double-circuit line into two single-circuit lines, or a multi-circuit line into two or more single-circuit or multi-circuit lines. The circuit remains unchanged after decomposition. A branching tower may have one side in the same direction and the other side branching, or both sides may have branching lines.
