Eltel Transmission Finland and Fingrid have signed a contract on changing of earth wires for 400-kV lines during 2011-2012. The contract comprises replacement of 1100 km earth wire of which 400 km is optical ground wire (OPGW). These five lines are part of a critical interconnection between Finland and Sweden and are located in northern Finland. Fulfilling the required outage targets are of paramount importance in the contract. During the outage period the line under work is out of operation.
The need for replacement of old earth wires made of steel arises from a need to limit hazardous voltages close to the lines. The new earth wire type is made of steel reinforced aluminum alloy. The use of OPGW for certain sections is based on enhancement of communication lines.
"The new contract will be the third earth wire replacement project engaged by Fingrid and won by Eltel Transmission Finland. In the previous two projects all the outage targets were fulfilled. The client has also appreciated the high quality of delivered materials and our stringing works. In the latest completed project Eltel’s performance using Fingrid’s own scoring system awarded Eltel 26 points out of maximum 29 points, classifying Eltel as a "5 Star" Contractor", says Tapio Leskinen, director of Eltel Transmission Finland.
The overall length of replaced earth wire after this project will be 2350 km of which 600 km is OPGW. One 24-km section has been performed on de-energized line while fulfilling all requirements for live-line working conditions, utilizing tension and cradle block method for crossings.
In the execution of the projects above Eltel is utilizing its cross border resourcing by setting up teams from its Finnish and Polish Transmission units.