Challenging Cable Survey for Statnett

Statnett took over three marine cable connections in Lofoten/Vesterålen, Northern Norway, on 1 January 2015. The cables were owned by Trollfjord Kraft and Lofotkraft and include Hadselfjorden, Langøysund and Sløverfjorden. A cable inspection and position survey along with a geophysical survey were carried out by MMT on these cables before the cables were taken over by Statnett. A cable inspection and position survey along with a geophysical survey was also carried out at Rombaken located in the inner parts of Ofotfjorden.

The aim of the cable inspection and position survey is to identify condition, position and possible burial depths of the cables.

MMT conducted the cable inspection and position survey by M/V Stril Explorer using the Work Class ROV Kystdesign Supporter. In Rombaken it was a challenging survey for the ROV with almost vertical slopes on both ends of the fjord. The cable tracking system used was the ORION system by Optimal Ranging. It was the first time MMT used the system on HVAC cables and the system showed good positioning horizontally and promising results vertically. 

Image: Challenging ROV survey for Statnett on vertical slopes in Rombanken, Norway.