A vessel (1) with a transfer installation for cargo and persons towards an offshore construction (12) comprises means for stabilizing its position at sea relative to the offshore construction (12), a telescopically extendable beam assembly (2) that comprises telescopable beam elements (2a, 2b), which beam assembly (2) with its one outer end (15) is rotatably connected to the vessel (1) by means of an axle system (7a, 8a, 9a), and a driving device designed to bring the other outer end (16) of the telescopically extendable beam assembly (2) in contact with a landing provision (13) of the offshore construction (12). The telescopically extendable beam assembly (2) is provided with means for moving a transportation carriage (14) back and forth between both outer ends (15, 16) along the telescopically extendable beam assembly (2), wherein the transportation carriage (14) is provided with a support (20) for carrying the cargo and persons.

A mooring apparatus (50) comprising a guide portion (55) for guiding a portion of a first mooring line (60), an arrangement (65) for connecting or coupling the apparatus (50) to a second mooring line (70), and a lock (75) or lock means. The guide portion (55) is moveably connected to the arrangement, and the lock is connected to, attached to or provided on the arrangement. A system (250) for tensioning a mooring line, the system comprising the mooring apparatus (50) and the first mooring line (60) and/or the second mooring line (70). A method of tensioning a mooring line, wherein the method comprises providing the system for tensioning a mooring line, and the method further comprises applying a pulling force to a first portion of a first mooring line (60) in a direction away from the apparatus (50).

There is disclosed an apparatus for mooring a structure, the apparatus includes a first portion for receiving a portion of a line, such as a mooring line, extending from a structure. A guide portion for guiding a/the portion of a line received by the first portion, the guide portion being movably connected to the first portion and a second portion for connecting or coupling the apparatus to a seabed or a further structure located thereon, the second portion being movably connected to the first portion and/or guide portion.

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 system and method for mating equipment offshore to a spar buoy secured to a foundation without the use of a crane barge. The system comprises a floating vessel having a pair of forks defining a slot. A gimbal table, defining an opening, is positioned within the slot and connected to the vessel and a locking collar is mounted to the gimbal table. A mating member is attached to the spar buoy. The vessel is maneuvered to bring the spar buoy within the gimbal table opening. With the spar buoy positioned within the gimbal table opening, the locking collar is arranged and designed to releasably attach to the mating member of the spar buoy and restrict relative vertical motion between the spar buoy and the vessel while the gimbal table allows the floating vessel to roll and pitch without driving these motions into the spar buoy.

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 method of repositioning a floating offshore wind turbine located at a current offshore position and having rotor blades rotating in a rotor blade plane includes: measuring a first value of a variability of a load related to a first location at the wind turbine; measuring a second value of a variability of a load related to a second location at the wind turbine; comparing the first value with the second value; and moving the wind turbine along a direction depending on the comparison and in particular further depending on the first location relative to the second location.

Semi-submersible offshore support structure for a wind turbine comprising three semi-submersible columns that are connected to each other by a connection structure, wherein the connection structure defines three sides of the support structure, wherein the support structure further comprises a wind turbine receiving element for receiving a wind turbine tower, wherein the wind turbine receiving element is positioned on a side of the support structure between two semi-submersible columns.

A method of installing an object under water at a desired location includes providing the object on a vessel, connecting the object to a submersible frame located below the water surface, wherein the vessel is spatially separated from the submersible frame along the direction of the water surface, releasing the object from the vessel such that the object becomes submerged and carries out a pendulum motion until the object is suspended from the submersible frame, and moving the object to the desired location.

Mooring chains used in offshore environments are typically formed from carbon steels due to their wear and fatigue resistance properties. Although carbon steels may exhibit robust mechanical properties, they are susceptible to corrosion, which can shorten the usable working lifetime of mooring chains, particularly in a seawater environment. Austenitic steels comprising high percentages of manganese may have comparable mechanical properties to the carbon steels commonly used in mooring chains, yet exhibit less susceptibility to corrosion. Austenitic steels suitable for use in mooring chains and other structures in contact with or exposed to a seawater environment may comprise: 0.4-0.8 wt. % C, 12-25 wt. % Mn, 4-15 wt. % Cr, a non-zero amount of Si<3 wt. %, a non-zero amount of Al<0.5 wt. %, a non-zero amount of N<0.1 wt. %, <5 wt. % Mo, and balance Fe and inevitable impurities.