The horizontal bridge is provided with a bridge Gantry Crane that forms the mast shape on both legs. The Gantry Cranes are operated on the ground track and are mainly used for handling and installation operations in open storage yards, docks, power stations, ports and rail cargo terminals. Gantry Gantry Crane hoisting mechanism, car running mechanism and bridge structure, and bridge Gantry Crane is basically the same. As the span is large, the Gantry Crane operating mechanism are mostly driven separately to prevent the Gantry Crane from generating skew operation and increase resistance, and even accidents. Gantry Gantry Crane is running on the bridge, and some Gantry Crane is a boom Gantry Crane. The legs on both sides of the bridge are generally rigid legs; span of more than 30 meters, often one side of the rigid legs, and the other side through the ball hinge and bridge connecting the flexible legs, so that the gantry into a static system , So as to avoid the external load due to lateral thrust caused by additional stress, but also to compensate for the vertical deformation of the bridge. Gantry Gantry Crane wind area, in order to prevent the use of strong winds in the taxi or overturned, equipped with wind measuring instrument and interlock with the operating mechanism of the Gantry Crane clip rail device. The bridge can be either cantilevered at both ends; it can also be cantilevered at one end or both ends to expand the operating range. The semi-gantry Gantry Crane has one end with a leg and the other end without a leg, running directly on a high platform. Gantry Gantry Cranes are divided into four types.
① ordinary gantry Gantry Crane: This Gantry Crane (see color map) the most widely used, can carry a variety of items and bulk materials, from the weight of 100 tons, the span of 4 to 35 meters. The gantry Gantry Crane with a general level of work is higher.
② hydropower station gantry Gantry Crane: mainly used for lifting and opening and closing the gate, but also for installation operations. From the weight of 80 to 500 tons, the span is small, 8 to 16 meters; lifting speed is low, 1 to 5 m / min. Although this Gantry Crane is not often lifting, but once the use of work is very heavy, so to properly improve the work level.
(3) shipbuilding gantry Gantry Crane: for the ship to assemble the hull, standing with two lifting trolley: one has two main hook, on the trajectory of the bridge on the track; the other has a main hook and a hook, The rails on the lower flange of the bridge are running so that the large hull segments are turned over and hoisted. Lifting capacity is generally 100 to 1500 tons; span of 185 meters; lifting speed of 2 to 15 m / min, there are 0.1 to 0.5 m / min fretting speed.
④ container gantry Gantry Crane: for container terminals. The container is transported from the vessel to the yard or rear, and the container gantry Gantry Crane is stacked or unloaded directly to speed up the movement of the container carrying bridge or other Gantry Cranes. Can be stacked high 3 to 4 layers, 6 rows of containers of the yard, the general use of tires, but also useful track. Container gantry Gantry Crane and container trailer compared to its span and mast on both sides of the height are larger. In order to meet the transport needs of the port, the Gantry Crane has a higher level of work. Lifting speed of 8 to 10 m / min; span according to the need to cross the number of containers to determine the maximum, about 60 meters. Corresponding to 20 feet, 30 feet, 40 feet long container from the weight of about 20 tons, 25 tons and 30 tons.