APL Neptune Deep Water Port Project
Location: Boston Bay, Massachusetts, Offshore USA
Project description:
The Neptune Deep Water Port Project is located offshore east of the Massachusetts Bay in international water. The company Neptune LNG will run this offloading development.
During operation an LNG tanker moors to a single point mooring system and offloads re-gasified product directly into the US gas distribution network. The system is based on the Submerged Turret Loading (STL) technology developed by APL. This system consists of a buoy / turret structure, connected to the seabed by nine mooring lines. The buoy / turret structure has integrated guide-tubes for a flexible riser and umbilical. These are permanently connected to the buoy / turret structure. When on location, the LNG Tanker pulls in the STL buoy, locks on and connects to the flexible riser and umbilical whereupon offloading can commence.
The dual STL Subsea System for the NEPTUNE Project in Massachusetts Bay is a disconnectable system allowing tankers to lower the buoy to its rest position prior to departing for the next loading port. The system is installed in a nominal water depth of 78m (North System) and 81m (South System) respectively.
Timing and duration: 14 months
Completion date: Summer 2009
Our scope: APL has contracted PDi to project manage the flexible riser gas lines and umbilicals installation engineering works covering both onshore preparation and offshore execution. This also included design of the system required to enable product lay from storage reels over the vessel side and installation of buoyancy units and other appendages to the products during deployment from the Normand Clipper.