A support structure for supporting a lift crane, and in particular to a lift crane jack-up structures, including rigs, platforms, barges, boats or the like, wherein the lift crane is positioned about a leg of the jack-up structure atop the jack-house. 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. A structurally reinforced jack-house having jacking units
interfacing with the leg is provided at the
deck of the vessel the jack-house configured to engage and support a crane tube column upon the roof of the jack house, which crane tube column in turn has situated thereupon the lift crane. The combined jack-house / crane tube
column design allows one to support a crane above the
deck in a stable manner independent of the leg situated therethrough, so as to provide a superior structural support for the lift crane, while providing ample space within the jack-house for the jacking units. The combined jack-house / crane support structure thereby affords significant space savings upon deck of the platform, while providing enhanced support of the lift crane. The
substructure of the vessel comprises longitudinal and transverse bulkheads intersecting to form a support
cell having a perimeter, the portion of the bulkheads forming the
cell extend vertically through the deck to form the walls of the jack house and support for the platform. In an alternative embodiment, a truss-type bracing
assembly engages the perimeter of the support
cell below deck to form a raised platform without walls.