An arctic jackup truss leg comprises a plurality of chords, an outer bracing network with a plurality of bracing elements connecting the plurality of chords, an internal bracing network with a plurality of bracing elements, and a bridge plate network with a plurality of bridge plates, wherein each bridge plate has two ends that are coupled with the bracing elements of the outer bracing network and the internal bracing network respectively.

A method for installation of an elongate element in a stretch of water, the method including reversible fastening of a connecting member (34) at a first end (16) of the elongate element (10); arranging the elongate element (10) in a substantially horizontal configuration; reversibly engaging the connecting member (34) in a retaining member (36); pivoting the elongate element (10) about a substantially horizontal axis to move the elongate element (10) into a substantially vertical configuration, while the connecting member (34) remains engaged in the retaining member (36); joint lowering of the retaining member (36), the connecting member (34) and the elongate element (10) in the stretch of water (12) with the help of a lowering line (152); detaching the connecting member (34) of the first end (16) of the elongate element (10), and joint raising of the retaining member (36) and the connecting member (34).

A jack-up crane vessel or semi-submersible crane vessel is provided including a hull with a deck, and a crane on the hull for hoisting a load outside the deck. The crane includes a slewing crane base with a first suspension, an elongated boom that is rotatable around a horizontal rotation axis with respect to the first suspension, at least two pendants between the boom and the first suspension that mutually converge toward the distal boom section, a boom spacer between the boom and the first suspension, and a boom luffing installation for driving the rotation of the boom around the horizontal rotation axis between a lowered transport position and a raised operational position. In the direction of the vertical rotation axis the first suspension extends at least in the lowered transport position of the boom above the boom heel of the boom.

For controlling movement of a cantilever of an offshore platform, displacements required for displacing an item to a target position including longitudinal skidding displacement and transverse skidding displacement of the cantilever of the cantilever are determined from current position data and target position data. From position dependent support load data support loads during the longitudinal skidding displacement are determined. If and until a sum of support loads or a highest support load decreases during the longitudinal skidding displacement towards the target position, the longitudinal skidding displacement precedes the transverse skidding displacement. If a sum of support loads or a highest support load increases during the longitudinal skidding displacement towards the target position, the transverse skidding displacement towards the target position precedes the longitudinal skidding displacement.

Method for stabilizing a jack-up platform unit, the unit including a hull, a plurality of legs which are extendible from and/or through the hull and which are arranged to support the platform unit during off-shore operations, and a jacking system arranged to move the legs between a transport position and an operational position, wherein the jacking system is also arranged to move the hull along the plurality of legs between a floating position and an operational position, the method comprising the steps of lowering the plurality of legs until the legs stand on or in the seabed, raising the hull substantially above the sea surface, temporarily applying a preloading on the plurality of legs, further raising the hull to an operational height above the sea surface.

The present invention provides an assembly platform of a large tidal current energy generating device. The assembly platform is internally provided with at least one horizontal axis hydro-generator. The assembly platform includes supports, at least four fixed piles, at least two sleeving members and at least two force-bearing supports. The fixed piles are connected through the supports to form an installation space. The hydro-generator is installed inside the installation space, one end of each fixed pile is driven to be fixed to a seabed and the other end extends to be above a water surface. Ends of the at least two force-bearing supports are respectively mounted on the left and right sides of the horizontal axis hydro-generator along the water flow direction and the other ends are respectively provided with corresponding sleeving members so as to resist an impact force of a water flow on the horizontal axis hydro-generator.

A system is disclosed including but not limited to a a jack up processor in data communication with each for dynamically balancing loads in real time on a plurality of legs supporting a jack up rig platform having a plurality of gear box motors on the plurality of legs. A processor reads data from sensors on gear box motors on the legs and selects a stored torque profile from a computer readable medium based on the load data from the sensors; and sends the torque profile to the plurality of gearboxes. A computer readable medium and neural network are disclosed for dynamically balancing loads on the plurality of legs in real time.

A spud greasing system includes a spudwell and a spud configured to slidingly engage with the spudwell between a deployed position and an undeployed position. The spud includes an access window configured to align and correspond with a window of the spudwell when the spud is in the undeployed position. A sheave assembly is mounted in the spud and includes a first sheave and a second sheave rotationally mounted proximate a front end and a back end of the housing, respectively. When the spud is in the undeployed position, a grease supply is configured to be selectively connected to a supply pipe through the window and access window of the spudwell and spud thereby supplying grease to the first sheave of the sheave assembly without removing the spud from the spudwell.

A device and a method for securing a connection to be formed between a leg of a marine structure and a pile of a fundament fastened in a seabed. The connection has the leg partly inserted into an opening of the pile. The device is configured to be firmly connected to the leg. The device comprises a sleeve element configured, together with the leg of the marine structure, to be brought to vicinity of an upper portion of the pile. The device further has a clamping arrangement attached to the sleeve element comprising at least one clamping device configured to form an attachment between the sleeve element and the upper portion of the pile.

The invention relates to a system (1) for use with a crane (4) on a surface vessel (3), comprising a crane tool (15) attached or attachable to a hoisting cable (5) of the crane (4) and one or more adaptors (16) attached or attachable to one or more tools (11-14, 25) for carrying out operations or to one or more components (2, 10), the crane tool (15) comprising a connector (17) and at least one of the adaptors (16) comprising a connector-counterpart (18).