Patent ID: 8425155

Claim:
A jacking system for a leg of a jack-up platform, comprising: at least three independent yokes, each yoke being connected to a jack-up structure by at least one vertically arranged double acting actuator and being equipped with a leg engaging mechanism, which is configured to engage and disengage with a hole of the jack-up leg, in order to transfer a load from the jack-up platform to the leg; and an anti-rotation provision configured to prevent rotation of the leg relative to the platform, wherein said anti-rotation provision includes: a plurality of guidance shoes, at least one of the guidance shoes being provided on each of the three independent yokes; and a plurality of vertical guidance pillars, the vertical guidance pillars being fixed together by rings surrounding the leg, and arranged for slidingly guiding the three independent yokes via the plurality of guidance shoes, wherein the plurality of vertical guidance pillars and rings are connected to the platform such that a sub-assembly including the vertical guidance pillars and rings is supported by the platform in a vertical direction and a tangential direction of the leg, but freely moveable in a radial direction with respect to a transverse cross-section of the leg, to prevent rotation of the leg when engaged by a leg engagement mechanism and permit the vertical guidance pillars to be horizontally guided by the leg.