After positioning the structure offshore, Jan De Nul must ballast it with some 350,000 tons of heavy metal ore for which a pumping installation will be tested and installed on the barge ‘DN 120’. Subsequently, rock will be installed along the platform by the new side dumping vessel ‘JDN 8623’ to protect the structure against scour.

The new side dumping vessel will have a capacity some three times greater than that of the current largest side dumper. The massive capacity will enable lower cost installation of rock armour for scour protection to offshore platforms and pipelines as well as marine breakwaters.

A rapid sailing speed will enable it to load directly from quarries rather than take transshipments from supply barges. The vessel will feature DP class 2 dynamic positioning for safe operation alongside platforms and other structures. It can also be equipped with a telescopic fallpipe installation.

Meanwhile, at Ras Laffan in Qatar itself, Jan De Nul is performing landfall trenching for Qatargas and Rasgas. The nearshore section will be trenched with a newly developed elevated excavator with a rock breaker whilst the offshore section will be dredged by the backhoe dredger ‘Jerommeke’. The pipelines will bring gas onshore from offshore fields for liquefying and onward transport via tankers.

At Melut Basin in Sudan Jan De Nul’s largest trailing suction hopper dredger ‘Vasco da Gama’ is trench dredging through hard coral soil at depths of 50m. A newly designed ‘ripper’ draghead makes such work possible and dredged materials are being displaced sideways from the trench by rainbowing.

Jan De Nul’s recently awarded projects have a total value of some $100m.

MJ Information No: 22504