Universal joint for offshore platform leg - to sea-bed foundation prevents uncontrollable forces by floor irregularities

摘要

A universal joint for each of the legs of an offshore drilling and/or production platform is arranged between the pivot at the end of the leg and a coaxial bore in a bracket of the foundation on the sea bed. A ring located in the bore has a concave spherical inner face and a ring located on the leg pivot has a convex spherical outer face which forms a partial ball-and-socket joint. This removes uncontrollable forces which would be caused by sea bed irregularities if the joint were only movable in one plane.