Floating vessels or structures are moored to the sea floor by mooring line assemblies connecting the floating vessels to anchors fixed the seafloor. Disclosed is a method of tensioning the mooring line assemblies to a desired tension, without applying tension forces from the vessel or structure being moored.

A method for installing a sea floor anchor includes building a drill string from a vessel having a cementing hose, drilling a hole in the sea floor, lowering an anchor member from the vessel into the hole, and cementing the anchor member in place in the hole with the cementing hose.

It is an object of the present invention to provide a means of constructing an Autonomous fully-Submersible Offshore Marine Platform (ASOMP) of considerable warfighting or commercial capability which is mobile and can autonomously transport to a hazardous operating area in a low-observable reduced vulnerability manner, fully submerge to avoid the military or environmental threat hazard, hibernate until needed, perform fully submerged mobility and mission operations, surface and provide Barge and SWATH surface ship mobility and mission operations, resubmerge if the hazardous threat appears and relocate to a new operating area. Another object of the present invention is to provide a fully autonomous and submersible low-cost lily-pad that surfaces when called and provides a main deck platform at appropriate freeboard and seakeeping motions to function as a refueling landing zone and pier to extend the range of aircraft and marine vehicles operating in a high-threat environment.

The present techniques are directed to systems and a method for reducing trenching around piles. An exemplary method includes attaching a mooring line to one end of a padeye extender bar that is coupled by another end to a padeye on the pile. The pile is installed in a sediment layer. The padeye extender bar is deployed to hold an attachment point for the mooring line above the sedimenlt layer.

A pile anchor reinforcing system includes a pile anchor having an end penetrating a seafloor, and a reinforcing pile penetrating the seafloor past the end of the pile anchor and being operatively coupled to the pile anchor to reinforce the pile anchor against lateral and vertical loading.

A tensioning system of a mooring line of a floating structure. The mooring line includes separate first and second mooring line sections, with a first end of the second mooring line attached to the floating structure and a first end of the first mooring line section being attached to an anchoring device embedded in a seabed. A tensioner configured to act on the mooring line includes a body with a housing, and an inlet unit for inserting a second end of the first mooring line section into the housing of the body. The body includes an opening for the passage of a second end of the first mooring line section from the inlet unit, through the housing, and along a direction changing element. The tensioning system includes a stabilizing platform fixed to the body. At least a portion of the stabilizing platform laterally projects from the body of the tensioner.

A buoy (10) comprising a central column (12), an outer frame (14) attached to the central column with buoyancy which may be provided by the outer frame and/or by attached buoyancy units (16). The central column is negatively buoyant and is normally open at one end to allow water to flow in, and create an oscillating water column caused by waves. This water column dampens the effect of wave or other forces on the buoy, thus providing a more stable foundation for a wind powered generator. A further generator may be provided to extract energy from the oscillating water column. The buoy is normally attached to an anchor by one or more tension leg tethers which maintains the buoyancy below the surface of the water which has also be found to increase stability. The anchor may be a modular gravity base anchor.

A technique for calculating the motion and stress at any location along a riser or mooring line that is connected to an oil platform using data from multiple motion sensors that are installed above the water level on the platform is disclosed. A relationship between motion at the locations of the motion sensors and motion at the point at which the riser or mooring line is attached to the platform is determined from a model of the platform. From this relationship, the motion at the location at which the riser or mooring line is attached to the platform is computed from motion that is measured by the motion sensors. The motion and stress at any location along the riser or the mooring line is calculated based on the acceleration at the location at which the riser or mooring line is attached to the platform.

A yoke mooring system and method for disconnecting a moored vessel from a tower structure. The system can include a support structure with one or more extension arms suspended from the support structure. A ballast tank can be connected to the one or more extension arms, and a yoke can extend from and connect to the ballast tank. The yoke can include a tower connector disposed on a second end thereof for connecting to the tower structure. A first winch system can be located on the support structure and connect to the yoke proximate a second end of the yoke via a first line or cable. A second winch system can be connected to the ballast tank via a second line or cable

The invention relates to a mooring tensioning arrangement for a floating structure or a vessel (11), comprising -a mooring line (3, 5, 7) having a first mooring part (3) and a second mooring part (5, 7), divided by a midwater coupling (4, 40, 400, 111), said at least a portion of the mooring line (3, 5, 7) is made of synthetic material, -said mooring line (3, 5, 7) is extending between an anchor (2) arranged on the seabed and a pulling unit (9, 10, 42) arranged separate from the floating structure or vessel (11), said mooring line (3, 5, 7) is extending at least via a fairlead pulley or a chain wheel (8, 80) arranged on the floating structure (11) between the anchor and the pulling unit (9, 10, 42) when the mooring line (3, 5, 7) being pre-tensioned, -a chain stopper (6, 60) being arranged in connection with the mooring line (3, 5, 7) between the anchor (2) and the floating vessel or structure (11) for tensioning the part of the mooring line (3, 5, 7) situated between the floating structure (11) and the anchor (2) at a pretension level. The mooring tensioning arrangement further comprising a second tensioning line (100) configured to be attached in one end to the midwater coupling (4, 40, 400) and in the other end coupled to the pulling unit (9,10, 42) when said mooring line (3, 5, 7) being re-tensioned, said midwater coupling (4, 40, 400) and the pulling unit (9, 10, 42) being arranged relative each other such that the tensioning line (100) is configured to impose a lateral force on the part of the mooring line (3, 5, 7) arranged between the anchor (2) and the floating structure (11) for removing stretch in the mooring line (3, 5, 7). The invention also relates to a method tor tensioning the mooring tensioning arrangement.