Special crane ship for transporting & erecting bridges on sea

A special-purpose hoisting ship for transporting beams on the sea relates to a hoisting ship which is for transporting, constructing, and installing large-scale bridge precast or preassembling components on the sea. The hoisting ship comprises a ship hull, a torsional box, a hoisting frame, a banded bracket, a polar crane, a hanging beam shoulder pole, a hoisting mechanism, an operational control system, and a mooring system. The ship hull is connected with the torsional box, which forms an integer, and the distance between two boats are 5 to 18 meters, and thereby the hoisting ship is not only suitable for constructing freely supported beams and double cantilever beams, but also suitable for hoisting and installing precast abutment bodies, sinking platform mechanisms, and other objects. The utility model adopts center hoisting modus, which means the center portion of a hoisting point of a crane is arranged near the buoyancy center of the ship hull, thereby achieving installing contraposition of heavy bridge components, realizing constructing safety, sufficiently utilizing and exerting the capability of the structure of the ship hull , and actualizing technique economics. The utility model with max elevating capacity of 2500 tons and max lifting highness of 41 meters is characterized by simple and direct construction, high efficiency in operation, great capability of resisting wind and wave, and great capability of adapting ocean environment.