Three months ahead of schedule, a new 132 kV power line entered service between Skogfoss and Varangerbotn in Finnmark County, despite Statnett attempting to do something the company had never done before – using composite pylons for parts of the section. This is the first time in Statnett’s history that such pylons have been installed. Composite pylons are made from polyethylene resin and fiberglass. According to the manufacturer, they require almost no maintenance. Although composite pylons are more expensive, they may be more economical as they have a longer lifespan and lower maintenance costs. Composite pylons on the entire section would also reduce the construction period significantly.
“This is the first time Statnett has used composite power pylons. The pylons are lighter than wooden power pylons and can be transported, preassembled, by helicopter. However, for this project, the pylons were installed in an area that we could get to by vehicle,” says Subproject Manager Astor Aspeli.
Statnett used the same foundation method as for wooden power pylons. This means they are installed on “uncompacted material”, and to avoid scars and damage a geotextile cloth was used between the pylons and the foundation. Three of the composite pylons were installed by the Reppen gravel pit in Nesseby in Finnmark County – a very exposed and windy area. The fourth pylon was installed at Skogfoss, where temperatures are often very low.
“At these locations we will be able to test how well the pylons can withstand the cold,” says Aspeli. Wooden power pylons have been used for the rest of the section.
Important for industry
The Finnmark power line is part of the next generation main grid. The new line will improve security of supply throughout Finnmark County – particularly in Eastern Finnmark.
“This is very important for the Kirkenes area, which is a future centre of industrial growth in Northern Norway,” says Statnett CEO and President Auke Lont.
Construction started in March 2010 with several local companies as subcontractors. The project is scheduled for completion in late summer 2014, with only minor substation work remaining.
Text: Lise Tønsberg Vangerud Photo: Statnett