June 2007 - ”NorNed - Kp 47" part 2

JD-Contractor A/S was hired to handle the world’s longest underwater cable ”NorNed”

The Norned High Voltage cable is a power cable laid out between Holland and Norway. Due to its length, the cable had to be laid out in several lengths and jointed together. At Kp 47 the normal inline jointing was not possible and an alternative setup and procedures had to be developed. JD-Contractor A/S has very long experience with the handling of this kind of cable and operation, therefore Statnett requested us to take over the engineering, planning and supervising of the operation.

The jointing at Kp 47 offered some challenges due to the construction of the cable which resembles the construction of a flat-cable. The handling of this kind of cable is delicate since any influences on the cable should be limited to turning at one axis at a time. Further more, the jointing due to technical reasons was to be made across the stern of the cable laying vessel M/S Skagerrak. This called for a very accurate planning of every movement of the vessel and cable during the work and made good use of the experience JD-Contractors’ employees possess after many years of handling flat-cables.

After a period of careful planning, a task plan was agreed upon and approved and subsequent procedures were made. M/S Skagerrak was mobilized in Frederikshavn, and equipped for a jointing operation across its stern. The jointing operation took a couple of weeks. After it was successfully carried out, M/S Skagerrak was demobilised and handed back the Norned cable to (the vessel involved in the laying) for the continuing laying of the cable. A technical accomplishment made by the personnel from JD-Contractor A/S was then completed.