**2.1. Covered conductors**

The most widespread structure of covered conductors consists of the core made from hard, compact aluminium alloy and a watertight/waterproof mantel made from a cross-linked polyethylene (XLPE). The use has shown the reliability of this type of conductor in very difficult conditions. It will withstand the weight of a fallen tree for days, mechanically and electrically.

Because of the outer mantel, the covered conductors are not that vulnerable when touching each other, or in contact with tree branches. This enables the spacing between phases/cables to shrink to one third of the space between normal over ground power lines. The platform for an over ground power line in a wooden area can therefore be smaller/narrower.
