Offshore jackup elevating and leg guide arrangement and hull-to-legs load transfer device

A method of of operation of a locking load transfer device for an offshore jackup platform's hull to be supported by legs which have one or more vertical toothed gear racks and pinion gear drive units attached, said method comprising the steps of:

• mounting at least one block to a first vertically movable alignment guide which is mounted to a second horizontally movable guide which is mounted to the hull of said offshore jackup platform, forming at least one protruding lug extending from one face of said block, wherein said lug is configured and oriented for insertion from a side of said gear rack between said teeth of said gear rack, shaping the lower face of said lug for engagement against one of said upper faces of said gear rack teeth;
• moving said block in a direction normal to the flat sides of said gear racks from a first retracted position to a second engaged position, while maintaining the desired horizontal alignment positions, normal to the directions of travel;
• and adjusting a vertical locking column mounted to said hull to bear against said block and lock said lower face of said lug against said upper face of said gear rack tooth to prevent downward movement of said hull relative to said leg.

A method of rigidly and releasably locking an offshore jackup platform's hull in position relative to the legs of the jackup rig which have one or more vertical toothed gear racks and pinion gear drive units attached, said method comprising the steps of:

• mounting a locking block with at least one protruding lug formed to engage with the rack teeth of said jack up rig to a first guide permitting movement in a vertical direction which in turn is mounted to a second guide permitting movement in a horizontal direction normal to the side face of said gear rack, jacking the rig while moving said block and first guide horizontally and normal to and toward said rack teeth until said teeth and lug align, moving said block and lug further horizontally into engagement of the lower face of said lug with at least one upper face of a gear rack tooth, jacking said rig additionally and moving said block vertically along the first alignment guide to a desired position, and locking said block vertically against downward loading with an adjustable bearing device fastened to the hull of said rig.