Corrosion protection of steel towers and camouflage of lines using the DUPLEX-system

摘要

Corrosion protection of steel towers using the DUPLEX-system is a relatively new method in the transmission line business, whereas this principle has been used successfully for decades for other purposes. The idea is to coat galvanized tower members as soon as possible after their production to use synergetic effects from zinc and the coating material. As a result, the lifetime of the protection against corrosion can be extended up to 40-50 years depending oh the environmental conditions. Another big advantage is that the towers can be camouflaged in the appropriate colour to blend with the environment. Also the shining effect of new galvanized towers can be prevented. Two methods shall be distinguished: i) the in-factory-DUPLEX-coating, where members are coated in the factory immediately after galvanizing before mounting and ii) the DUPLEX-coating on completely mounted towers, where the structures are coated as soon as possible after their erection. Both methods are proven and reliable principles for corrosion protection. Austrian Power Grid (APG) sees advantages in the DUPLEX-in-factory-coating and has been using this method successfully as protection for its steel structures since 1983. This article therefore concentrates on the in-factory-coating.