Bracing s are used to interconnect the legs of transmission lines, and the framing angle of the bracing and main leg of transmission towers should not exceed more than 15 degrees. Members of transmission towers are designed to compression and tension loads. Following are various patterns were used for bracing in Transmission towers.
- Portal System
- Pratt System
- Diamond Bracing
- Double web system
- Warren system
- Single web system
- Multiple Bracing
Single web Bracing System
In this single web bracing system, the struts are designed in compress and diagonal of tension. This bracing system got a narrow base, and these types of bracing types are much used in 66kV transmission lines. A single web bracing system consists of diagonal and struts of an all diagonal transmission tower, and this bracing system is widely used for narrow-based transmission towers.
Warren System
Warren bracing System is widely used for both large and small towers. In warren, bracing system tension diagonal will give effective support to compression one at point of connections.
Pratt System
Pratt bracing system used for large deflection under heavy load and unequal shears at the top of the focus stubs for design. Pratt type of bracing system is also used of the bottom two or three panels and warren bracing. In this bracing system, share carried by diagonal members, as shown in the figure.