The substitution of an existing ground wire by a cable combining the classical functions of an earth wire and telecommunications capacity has a long history. With first installations of this technology in 1978 Draka Comteq is provided with a more than 25 years lasting experience. Nowadays the optical ground wire (OPGW) is the most important and most accepted technology to equip high voltage lines with optical fibres world-wide.
An OPGW of course has to cover the classical functions of an earthwire such as short circuit and lightning protection .In addition the integrated optical fibres must be protected from mechanical and thermal loads. The challenge is to optimise the mechanical, electrical and data transmission properties in a way that all requirements coming from the overhead line design are fulfilled. The advantage is that all these functions are combined in one cable which reduces the additional loads for the towers.
Various designs based on fibres in stainless steel tubes offer the possibility to meet the requirements of the high voltage line. The most important characteristics are:
