Deepening of Mortingbåen and four surrounding shoals to -14.3 metres (nautical chart zero) will result in extraction of 141,000 pfm3 of mass in total, over an area of about 30,000 m2. The measure involves drilling, blasting and excavation for barges.

Deepening of Mortingbåen and four surrounding shoals to -14.3 metres (nautical chart zero) will result in extraction of 141,000 pfm3 of mass in total, over an area of about 30,000 m2. The measure involves drilling, blasting and excavation for barges.

Quantity calculations The deepening areas consist mainly of solid rock with the exception of the eastern side of Mortingbåen, where a layer of blasted rock remains from a previous deepening in 2003. At that time, it was deepened to -10 metres over an area of approximately 7600 m2. Based on geotechnical ground drillings, as well as information obtained regarding blasting that was carried out during a previous deepening, the Norwegian Coastal Administration estimates that the loose sand, gravel and blasted rock in this area has an average thickness of 1.5 metres. The total amount of loose soil at Mortingbåen is therefore estimated to be around 11,400 m3 .