Image Number 10 for United States Patent #6457908.
A method and apparatus for deployment of mooring systems for buoyant marine structure such as mobile offshore drilling units (MODU's) and for connecting the same to the mooring lines thereof. An anchor handling vessel carries one or more anchors each having a deployment connection and a mooring connection and individually moves each anchor over its stern roller and deploys it to the sea bottom for installation. A handling line is disconnected by ROV from the deployment connection and is moved from the deployment connection to the mooring connection so as to become the main mooring line. Syntactic buoys are then mounted on the main mooring line for elevating it above the sea bottom for recovery. When MODU stationing is desired the anchor handling vessel then recovers the surface buoy and connects to the rig mooring line using a short section of mooring chain. A J-chaser stopper device is then installed in the mooring string and is connected to the mooring line of the MODU by a short section of chain. The J-chaser lowers the mooring string, completing the mooring connection between the anchor and the MODU. A plurality of mooring strings, typically eight, are deployed in this manner to properly station the MODU. Disconnection of the MODU is accomplished essentially by the reverse of the above deployment procedure.