Traveling attachment for ring supported lift crane

In a crane having an upper structure pivoted on a lower carbody including crawler means for moving the crane over the ground, the combination comprising, a pair of support beams secured to and forming a part of said lower carbody, a track-like ring secured to said beams and horizontally surrounding said lower carbody and said crawler means, said beams extending fore and aft beneath and beyond the periphery of said ring, a boom carrier pivoted for vertical movement on said upper structure and riding for rotation on said ring, a boom mounted on said boom carrier for lifting a load, a counterweight carrier pivoted for vertical movement on said upper structure and riding for rotation on said ring, means interconnecting said counterweight carrier and said boom for counteracting a heavy load, and a traveling support attachment including a pair of laterally spaced crawler assemblies respectively attached outboard of said ring to the forward ends of said pair of beams by means including a cross frame interconnecting said crawler assemblies and a plurality of frame elements interconnecting said crawler assemblies and said lower carbody, said crawler assemblies are connected to said frame elements through vertical pivot posts, means for pivoting said crawler assemblies about the axis of said posts, and said cross frame including jack means mounted thereon to support said ring and to permit movement of said crane and ring over the ground while said boom is lifting a heavy load.