Clamping system for heavy "I" beams and the like on oil rigs, etc

A clamping system for "temporarily" fixedly joining together two "I" beam or girder type structures on for example an offshore oil rig to set up for example a portable crane on the platform structure. The system uses four sets of opposed pairs of clamping elements, each set of which includes two related pairs of clamping elements which grip the beams and are bolted together, the clamping system being used in place of welding the beams or girders together. When it is time to move the structure, the clamping elements are merely unbolted, allowing the removal or replacement of the portable crane on the platform structure. The four clamping elements of each set include two pairs of side-by-side members which are positioned along side one another to grip the opposite edges of the top flange of the bottom, support beam and bear down on the upper surface of one side of the bottom flange of the upper, crane girder. The other, opposed pair of clamping elements, located on the opposite side of the crane beam is also positioned along side one another to grip the opposite edges of the top flange of the bottom, support beam and bear down on the upper surface of the opposite side of the bottom flange of the upper, crane girder. Each clamping element includes moveable griping means, such as for example setting or bearing bolts, which are tightened down on the various beam flanges, locking the clamping elements to the beam flanges. The clamping elements are all then bolted together, "fixedly" locking the crane girder to the platform skid beam. An another application of the present invention is the mounting of a crane structure on the beam structure of a building construction site.