The fleet of Jan De Nul Group contains several types of rock installation vessels: Fall Pipe Vessels, Inclined Fall Pipe Vessels and Side Stone Installation Vessels.
A Fall Pipe Vessel (FPV) is equipped to install rock on pipelines and other subsea structures in deep sea. Using its fall pipe it is able to install rocks with a size up to 400 mm in up to 2,000 m water depth. The fall pipe end is positioned by a powerful remotely operated underwater vehicle (ROV) and allows for accurate rock installation on the seabed.
The Inclined Fall Pipe Vessel (IFPV) installs the rock in more shallow areas. A fall pipe along the vessel is used to install filter layers and rock armour along or even underneath offshore structures to protect it against scouring. With the DP system of the vessels, this installation can be done with high accuracy.
A Side Stone Installation Vessel (SSIV) pushes rocks over its side to protect offshore structures such as pipelines in shallow areas and to install underwater rock berms.