Abstract: A method for monitoring movement of a cantilever structure of an offshore platform, such as a jack-up platform or a self-elevating vessel, comprising providing a boundary model containing boundary limiting information of positions of the cantilever structure, wherein the boundary limiting information comprises at least position information of boundary limiting elements, such as obstacles; providing, during movement of the cantilever, position information of the cantilever representing an actual position of the cantilever; determining, during movement of the cantilever, a difference between the cantilever position information and the boundary limiting information of the boundary model; providing an output signal when the determined difference exceeds a predefined threshold value.

Abstract: Method for moving a cantilever with respect to a deck of an offshore structure in longitudinal and rotational direction, around a predetermined virtual vertical axis, without providing a fixed vertical rotation shaft, comprising providing an offshore structure with a cantilever movable with respect to a deck of the offshore structure, providing cantilever rails on the bottom side of the cantilever and providing a supporting member or a skid shoe to support the cantilever on the deck, wherein the supporting member or the skid shoe has a top part configured for allowing the cantilever rail to have an angle deviating from the centerline of the skid shoe during rotation of the cantilever.

Abstract: Telescopic lattice type crane boom for a crane, further comprising a locking system configured to lock at least one telescopic boom section with respect to a base boom section in at least an extended position, wherein said locking system includes a plurality of pins, each pin being configured to extend, in at least the extended position of the boom, at least partly through a corresponding pin receiving aperture provided in one of the base boom section and the at least one telescopic boom section.

Abstract: The invention relates to a monohull drillship (1), comprising an elongated hull (2) extending in the length direction (3) of the drillship. Said hull (2) is provided with at least one open moon pool (4) arranged to be located at the waterline (5) during use of the drillship. The drillship (1) is arranged for multiple-activity operations, e.g. simultaneous drilling and casing handling, in such a manner that drilling equipment can be passed through said at least one moon pool (4) at at least two locations (7, 8), i.e. at at least two so-called well centers, which are spaced apart from each other in at least a direction (6) substantially transverse to the length direction (3) of the hull of the drillship.

Abstract: A measurement system that comprises at least one horizontal load measuring unit, that is preferably arranged on the leg guide is provided. The horizontal load measuring device measures or determines horizontal load on the position of the leg where the device is placed, which gives a more accurate indication of the leg bending moment than the rack phase differential measurement. Advantageously, multiple load measuring units can be provided along the leg guide.

Abstract: Retractable thruster system for moving a thruster (1) on a vessel between an extended position, in which the thruster (1) is extended below a hull's bottom, and at least one retracted position, in which the thruster is located above the hull's bottom, the system comprising a canister (2) to which a thruster is mountable, wherein the canister is configured to be movable in a trunk (3) in a vessel's hull structure between said extended position and said at least one retracted position, and in which a rack-and-pinion lifting system is arranged to move the canister (3) in said trunk (3) between said extended position and said at least one retracted position, the lifting system including at least one rack (6) being fixedly connected to the vessel, and a pinion drive (7) including at least one pinion (8) arranged to cooperate with said at least one rack (6), said pinion drive being connected to the canister (2).

Abstract: The dual output pinion rack drive includes an epicyclic gearbox which permits the division of power of a single motor to first and second spur output pinions which are subjected to slightly different loading conditions based on rack geometry, rack tolerances and gear tolerances. A motor drives an input sun gear which drives planet gears which drive large and small ring gears in opposite rotational directions at similar torque levels while the carrier floats rotationally. None of the gearbox components, the sun gear, the planet gears, the large ring gear, the small ring gear, the planet carrier, and the housing are fixed rotationally. Each ring gear couples to first and second spur output pinions, respectively, and power is transferred through intermediate gear reductions and final planetary gear systems to first and second rack driving output pinions rotating in opposite directions driving the platform up a central rack.

Abstract: The drive system comprises a drive unit. The drive unit comprises a motor unit and a gear train coupled to the motor unit. The gear train comprises a differential planetary gear system having a single input shaft connected to the motor unit. The differential planetary gear system further has at least two output shafts of which each output shaft is arranged for driving a drive shaft. The differential planetary gear system comprises at least two single planetary gear sets.

Abstract: A torque sharing drive and process for sharing torque accommodates tooth inaccuracies on the rack and outer pinions. A driving pinion mates with first and second gears. The driving pinion is radially, bidirectionally, movable in response to gear separation forces only along the line between the centers of the driving pinion, the first gear and the second gear. First and second outer pinions are rotatable with the first and second gears, and as the driving pinion moves radially toward the first or second gear in response to gear separation forces, the first or second gear is angularly and rotationally advanced with respect to the other gear accommodating inaccuracies in the teeth of the rack and outer pinions. Alternatively, when gear separation forces are balanced, the driving pinion resides approximately equidistantly intermediate the first and second gear and the first and second outer pinions are approximately in phase.

Abstract: Vessel including a hull of a substantially closed surface has at deck level a lifting crane, ballast tanks within the hull and a ballast control unit for admitting water to the ballast tanks for changing the draft of the vessel. The hull has a narrow lower section having first width over a height from keel level to a widening level, and a top section having a larger width than the lower section, extending from the widening level upwards towards deck level. The control unit is adapted to ballast the vessel to have a relatively shallow draft level in a transit mode, so that the wide top section is above water level, while the vessel is traveling, and to ballast the vessel to a relatively deep draft level in a lifting mode so that the widening level is below water level, at least when the vessel is substantially stationary and the crane is in its lifting position.

Abstract: The drive system comprises a drive unit. The drive unit comprises a motor unit and a gear train coupled to the motor unit. The gear train comprises a differential planetary gear system having a single input shaft connected to the motor unit. The differential planetary gear system further has at least two output shafts of which each output shaft is arranged for driving a drive shaft. The differential planetary gear system comprises at least two single planetary gear sets.

Abstract: A jacking system for jacking a structure, includes a leg having a longitudinal axis and including first engagement parts along the leg, and a guiding frame displaceable along the leg. The guiding frame includes at least a first, second, third and fourth actuator, the actuators each having a first and second actuator part which in operation can displace with respect to one another along the leg, the first actuator part of the actuators coupled to the guiding frame, the second actuator parts of the actuators each coupled to first engagement parts for engaging and disengaging the first engagement parts of the leg for providing abutment in the longitudinal direction of the leg, the second actuator parts of the actuators displaceable along the leg past one another, and the actuators being arranged in pairs opposite one another with respect to a longitudinal plane of the leg.

Abstract: A jacking system (4) is described for a leg (3) of a jack-up platform (1). The jacking system comprises at least three independent yokes (7a-7d). Each independent yoke is connected to a jack-up structure by at least one vertically arranged double acting actuator (8a-8d?) and is equipped with a leg engaging mechanism such as a horizontally arranged movable locking pin (9a-9d), which is configured to engage or to disengage with a hole of the jack-up leg, in order to transfer a load (L) from the jack-up platform (1) to the leg (3), including a controller configured to operate the yokes (7a-7d) in a way that the leg (3) is moved by all the at least three yokes (7a-7d) in an alternating mode, such that at any moment in time during operation all but one of the at least three yokes (7a-7d) take the load (L) via the associated engaging mechanism, while the remaining yoke of the at least three yokes (7a-7d) makes a return stroke with its engagement mechanism in a disengaged position.