Horizontal tray provided in two branch legs constitute a bridge crane gantry shape. This crane orbit on the ground, mainly used in outdoor storage yard, shipyards, power plants, ports and railway stations and other places for cargo handling and installation homework.
Shipbuilding gantry crane hoisting mechanism, trolley traveling mechanism and bridge construction, bridge crane with basically the same. Because span, crane operating agencies they use are driven way to prevent the crane produce skewed running and increase the resistance, or even accidents. Gantry crane lifting trolley running on the bridge, some lifting trolley is a jib crane. Both sides of the bridge legs are generally rigid legs; when span of more than 30 meters, usually on one side of the rigid leg, while the other side is connected through a flexible leg and bridge the ball joint, the mast becomes statically determinate system , such as to avoid the outer lateral thrust loads caused additional stress, can also be compensated bridge gantry crane vertical temperature deformation by wind area, in order to prevent falling or tipping lines in strong winds, wind measurements and fitted organization and operation of the crane rail clamp interlock. Trays may be free at both ends of the cantilever; may be cantilevered at one end or both ends of the boom, in order to expand the scope of homework.
Semi-gantry crane bridge legs at one end and the other end without legs, running directly on the high bench. Gantry cranes are divided into four types.
① ordinary gantry cranes: This crane is the most versatile, can carry a variety of items and bulk materials, from the weight of 100 tons, a span of 4 to 35 meters. With common gantry crane grab a higher level of work.
② Station gantry cranes: mainly used for lifting and Gate, also can be installed homework. Lifting capacity of 80 to 500 tons, the span is small, 8 to 16 m; the lower lifting speed of 1 to 5 m / min. This is certainly not always the crane lifting, but once the work is very heavy use, it should be appropriate to the level of progress of work.
③ shipbuilding gantry cranes: for berth assembled hull, standing with two lifting car: There are two main hook of a run on the track on the bridge flange; another has a primary and a secondary hook hook in running on the bottom flange of the rail bridge to flip and lifting large hull segments. Weight is generally from 100 to 1500 tons; span of 185 meters; lifting speed of 2 to 15 m / min, and 0.1 to 0.5 m / min jog speed.
④ container gantry cranes: for the container terminal. After the trailer carrying the quay container bridge container ship unloaded from the ship to the yard or rear, stacking up by container
Wall mounted jib crane or transported direct loading can accelerate or other container bridge crane carrying turnover. Can be stacked three to four layers, wide and 6 rows of container yard, general use tire, it also has a rail type. Container gantry cranes and container straddle match, which spans both sides of the door frame height and are larger. In order to meet the transport needs of ports, the higher the level of this crane work. Lifting speed of 8 to 10 m / min; span container according to the number of rows needed to determine the span, up to about 60 meters corresponding to 20 feet, 30 feet from the weight of 40-foot-long containers were about 20 tons, 25 tons and 30 tons.
