Self-unloaders equipped with sub-sea rock installation (SRI) technology are typically used to accurately install rock in water depths of up to 2,200 metres. They can also be used for such activities as cable installation for offshore wind farms and side stone dumping. Self-unloaders with sub-sea rock installation technology are equipped with a flexible fallpipe and an onboard Remotely Operated Vehicle (ROV).

The fallpipe and ROV are lowered to the seabed at installation. Using advanced measurement instruments and underwater navigation equipment, the ROV secures the fallpipe in the correct position while a conveyor belt brings the rocks from the holds of the ship to a spreader and feeder on the deck. The rocks are then discharged through the fallpipe at a controlled rate for precise placement.

Diagram of a Self-Unloader Equipped with Sub-Sea Rock Installation Technology