October 2007 - Relaying of cable trace due to establishment of a new wind farm

Client: SEAS-NVE.

The work started on the 10 September 2007. JD-Contractor A/S exchanged the five existing power cables and one fibre-optics cable and then afterwards established and laid out 2 sets of pipeline systems with 5 cable pipelines in each one of them.

The recovery of the existing cables was carried out from the diving ship M/S Honte, assisted by M/V Lille Björn and our floating stage, which was rigged with crane, winches and one container for the cables. Furthermore a working place was mobilized ashore. At those places where the cable was deeply embedded into the seabed, the divers used suction and jetting equipment for free jetting the cable, before it was be possible to pull the cable onto the floating stage.

A total of approx. 5 x 235 metres of power cables were recovered in Masnedsund.

When the cables had been successfully recovered in the area, a trench with the depth of 3 metres and the width of 10 metres was excavated into the seabed. The excavating work was carried out by the two excavating vessels M/E Helle Saj and M/E Nicolaj Saj. In the meantime the two pipeline systems were welded together ashore. Parallel with the establishment and ballasting of the pipeline systems, they were pulled out in Masnedsund by M/S Honte.

As both pipeline systems were pulled out from ashore, M/V Lille Björn towed them, so they were in the cable trace and in a straight line parallel with the Masnedsund Bridge. The pipeline systems, which were air filled, were then filled with water in order to lower them down into the excavated trench. After the laying and the lowering of both pipeline systems were finished, the trench was covered up with the materials from the excavating.

A total of approx. 264 metres of trenches were excavated and as a result approx. 7,000 m3 of materials were removed in the area in Masnedsund. Afterwards approx. 2 x 264 metres of cable pipelines were laid out and the materials were put back into the trench.

The establishment of cable pipelines in Masnedsund was finished on the 11 October 2007. When finished, both of the pipeline systems were video filmed and approved by a diving team, before the floating stage and working place ashore were demobilized. M/S Honte and M/V Lille Björn departured from Vordingborg port on the 13 October 2007.

JD-Contractor A/S was responsible for the delivery of all materials for the project, as well as the welding, ballasting and establishment of the two pipeline systems.

For the work at Masnedsund the following vessels were used:

• The diving ship M/S Honte,
• the multi-working vessel M/V Lille Bjørn,
• the excavating vessels M/E Helle Saj and M/E Nicolaj Saj,
• the tugboat T/B Rita Saj with barge,
• four rubber boats
• and finally our floating stage.