Elevated crane support system and method for elevating a lifting apparatus

#The present invention relates to a support structure for supporting a lift crane and in particular to lifting cranes for use on jack-up type drilling rigs, lift boats, platforms, boats and the like, wherein the lift crane is positioned about a leg(s) of the jack-up structure atop the jack-house or yoke assembly.

#The preferred embodiment of the present invention contemplates a system for elevating a lift crane above the deck and about the leg of the jack-up structure, without relying upon the leg for structural support, unlike king post-type design lift cranes. A structurally reinforced jack-house or yoke assembly having jacking units interfacing with the leg, is provided at the deck of the vessel. The jack-house or yoke assembly is configured to engage and support a crane tub upon the top of the jack-house or yoke assembly, which crane tub has situated thereupon the lift crane.

#The structurally designed jack-house or yoke assembly allows one to support a crane above the deck in a stable manner independent of the leg situated there through, so as to provide a superior structural support for the lift crane, while providing ample space within the jack-house or yoke assembly for the jacking units. The combined jack-house/yoke assembly support structure thereby affords significant space savings upon the deck of the platform, while providing enhanced support of the lift crane.

#For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawings, in which like parts are given like reference numerals, and wherein:

#FIG. 1 is an isometric view of an exemplary jack-up vessel having the lift crane support structure/jack house of the present invention.

#FIG. 2A is a side, partially cut-away view of a jack-up platform having the lift crane support structure/jack house of the present invention with an exemplary 300 ton crane, illustrating the erection of a detachable rig kit.

#Referring to FIG. 1 of the drawings, the lift crane support structure/jack-house 1 of the present invention is integrated into the deck 13 of a vessel 3 such as a jack-up drilling rig, jack-up service vessel, barge, platform, or the like having legs 4 configured to engage the water bottom 5 to lift the vessel above the water level, the legs 4 passing through vertical, enveloped passageways 6 formed through the deck and hull of the vessel. To facilitate lifting or lowering of the legs 4, jacking units 11, 11′ are provided, generally within a jack-house 7.

#In order to provide a more stable, elevated platform for a crane to operate on the vessel, while lessening deck space requirements, the jack-house of the present invention is reinforced to allow the placement of a crane tub 16 emanating from the top of the jack-house, which crane tub has at its distal end a flange 20 for the rotatable engagement of a crane 10 thereupon.

#Continuing with FIGS. 2A-2C, 3A-3C, and 4A-4C, the jack-house 7′, 7″ of the preferred embodiment of the present invention comprises an above deck portion 12, 12′ and a substructure 14, 14′ situated below deck 13, 13′ such that the jack-house is structurally integrated into the vessel, with the base of the jack-house engaging the hull 19, 19′ of the vessel in the vicinity of the leg passageway 6′ for leg 4′. Below the deck, the jack-house substructure 14, 14′ may be reinforced by diagonal braces of support members 17, 17″ having first 17′ and second 18 ends, the first end 17′ engaging the jack-house wall members, the second end 18 engaging a bulkhead or otherwise inside of the hull 19, 19′.