Sjøentreprenøren AS was contracted in 2020 for dredging at Rosenberg Verft
The project was part of the preparations to receive the vessel Jotun A. The assignment consisted of dredging approximately 14,500 tonnes of contaminated loose materials and blasting about 9,000m3 of rock. Due to the level of contamination, all loose materials were loaded ashore and transported to Svåheia in Egersund by trucks. In addition, a silt curtain was used to prevent particle dispersion.
To secure the rock on which the quay structure stands, 332 rock bolts were installed and grouted. All bolts were installed with the help of a diver and support personnel on land. Because blasting was to be done right up to the quay line, there were strict requirements for staggered drilling with double threading, in addition to rock stabilization.
It was not possible to remove the silt curtain during the construction period, and an air bubble curtain was used as a substitute for the silt curtain when it needed to be lowered underwater to allow vessels to enter/exit the work area. An air bubble curtain was also used during blasting to dampen the shock waves that result from the detonation. This was done to protect marine animals and fish life outside the work area. The air bubble curtain was also used to protect nearby vessels.
Environment in focus – the seabed in balance
At Sjøentreprenøren, we are proud to have completed a number of successful maritime projects that demonstrate our expertise and dedication to delivering results that meet our customers' needs.
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