Statnett announced on 2 October that it had installed three new monitoring systems on the Sima–Samnanger power line in western Norway. The systems are on the crossings over Fyksesundet, Granvinsfjorden and Osafjorden. They measure conductor vibration and weather conditions to improve understanding of the stresses caused by wind and local terrain. The data are intended to inform maintenance planning and help extend the service life of long overhead spans across fjords.

Fjord crossings can stretch for several kilometres between pylons. Repeated wind-driven vibration may gradually wear conductors, dampers, insulators and other components. Statnett says each system includes vibration sensors, dampers fitted to the lines and a weather station on a pylon to record wind direction and speed. Continuous monitoring supplements calculations, visual inspections and shorter measurement periods used previously.

The monitoring equipment was developed through the D-fjord research and development project. Statnett says conditions can vary between fjords even when lines and dampers are similar. At one Hjørundfjorden crossing, the company found that phases of the same line type moved differently. Measuring more than one phase can therefore provide a fuller picture than monitoring a single conductor. The announcement does not claim that the system can predict every failure.

Three new systems were installed on the Sima–Samnanger line in early August 2026, and 20 vibration dampers were fitted. The first monitoring system had been placed on the line between Vik and Sogndal, which crosses the Sognefjord. Statnett plans to install a fifth system at Storfjord in spring 2027. That is a planned next installation, not a completed one.

Statnett intends to use measurements taken before and after reinforcement work to assess damping solutions and local conditions such as wind and terrain. Better information on loads may help target maintenance to the spans under greatest stress and reduce unexpected faults, the company said. The release’s reference to a possible ten-year extension of service life is an illustrative scenario, not a guarantee or measured result. No savings amount was published.

Accordingly, the release’s example of a longer service life is not a maintenance gain established by measured results. Sensors add information about line loads; operating decisions still rely on inspections, engineering analysis and safety requirements. Without later comparative data, the system’s effect on failure rates cannot be quantified.