The fleet of Jan De Nul Group disposes of two specific types of rock installation vessels: Fall Pipe Vessels and Side Stone Installation Vessels.
A Fall Pipe Vessel (FPV) is equipped for rock installation 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 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.
A Side Stone Installation Vessel (SSIV) is used for rock protection on offshore structures such as pipelines in shallow areas and for underwater rock berm construction. The rocks on board are pushed over its side. Some SSIV’s are equipped with an inclined fall pipe for rock installation underneath platforms and fixed structures.