Overhead lines: equipment - Supports

Supports in general, and pylons and poles in particular, are essential components of overhead power transmission and distribution lines.

The shapes and sizes of the supports vary from simple wooden or concrete poles a dozen meters high, to steel lattice towers over 50 m high and weighing 100 t or more.

Supports are defined according to the mechanical stresses created mainly by the conductors they support, and according to electrical insulation constraints.

This article presents the design rules for overhead line supports. It also provides an inventory of tried-and-tested technical solutions, as well as new, innovative solutions that take account of regulatory and environmental developments.

This article is an update with new additions of the article presented by Yves PORCHERON in 1992 in this treatise. Part of the text has been retained.

Overhead lines are the subject of a whole series of articles to which the reader can refer:

• "Line layout and calculation" ;

• "Dimensioning";

• "Conductors and ground wires" ;

• "Insulators";

• "Supports";

• "Support foundations";

• "Accessories";

• "Construction";

• "Maintenance" ;

• [D 4 431] "Find out more.