A gantry crane is a bridge-type crane in which a horizontal bridge is arranged on two legs to form the shape of a gantry. This crane runs on ground tracks and is mainly used for handling and installation operations in open storage yards, shipyards, power stations, ports and railway freight stations.
The gantry crane's lifting mechanism, trolley operating mechanism and bridge structure are basically the same as the bridge crane. Due to the large span, most of the crane operating mechanisms adopt separate driving methods to prevent the crane from generating skewed operation to increase resistance and even accidents. The gantry crane's crane trolley runs on the bridge, and some crane trolleys are a jib crane. The outriggers on both sides of the bridge are generally rigid outriggers; when the span exceeds 30 meters, one side is often a rigid outrigger, and the other side is a flexible outrigger connected by a ball hinge and the bridge, making the mast a statically indeterminate system. This can avoid additional stress caused by lateral thrust under external load, and can also compensate for the large wind receiving area of the longitudinal temperature deformation of the gantry crane. In order to prevent gliding or overturning under strong wind, a wind meter and Crane rail clamp interlocking with the running mechanism. The bridge can be without cantilever at both ends; it can also be cantilevered at one end or cantilevered at both ends to expand the working range. The semi-gantry crane bridge has one leg at one end and no leg at the other end, and runs directly on the high platform.
When lifting heavy objects, the hook wire rope should be kept vertical, and it is not allowed to tow the object diagonally.
The center of gravity of the lifted object should be correctly aligned and tied tightly. The use of sharp-edged mats is good.
Before the heavy object is lifted off the ground, the crane must not perform slewing motion.
When lifting or lowering heavy objects, the speed should be uniform and stable, to avoid the rapid changes in speed, causing the heavy objects to sway in the air, causing danger. When dropping heavy objects, the speed should not be too fast, so as not to damage the heavy objects when landing.
When the crane is under load, try to avoid landing booms. When the boom must be raised and lowered under lifting conditions, the lifting weight must not exceed 50% of the specified weight.
Two cranes work on the same track, and the distance between the two cranes should be greater than 3m.