Boskalis fleet of subsea rock installaltion vessels consists of three dedicated self-propelled DP-2 vessels equipped with a flexible fallpipe which can be lowered into the water. Uniquely, the subsea rock installation vessel can position rock with extreme accuracy down to a depth of 1,500 meters.
The vessels are highly suited to cover offshore cables and pipelines. They are also used to prepare the seabed for offshore structures and to put in scour protection for offshore wind turbines and platforms. Additionally a subsea rock installation vessel can be used to ballast the legs of offshore platforms, and this work can involve, for example, pumping a mixture of water and rock into the legs.
Our vessels have a capacity to hold 24,000 tons of rock which are taken on conveyor belts and thereafter sent through the chute into the fallpipe. The fallpipe and an ROV are positioned above the starting point to deposit rock with great accuracy. Depending on the project specifications, the vessel can position rock in various ways. When the fallpipe cannot reach the destined position of the rock, as in offshore wind parks or around offshore platforms, the side dumping unit is used.