The Horizontal bridge is disposed on two legs which constitute a gantry crane.
This gantry crane company is working by traveling rails on the ground, mainly used in open-air storage yard, docks, power plants, ports and railway stations and other places for cargo handling and installation operations.
Gantry crane hoisting mechanism, trolley traveling mechanism and bridge construction, are basically same with bridge crane. Because of long span, gantry crane are usually used by respective driven way to prevent the crane producing skewed running and increasing the resistance, and even accidents.
Gantry crane design on main girder
The relation between span and cantilever Cantilever takes up 1/3 of the span because when the load in the span middle the maximum bending moment is close to the maximum bending moment when the load in the cantilever sid. Notice: It should be satisfied with the whole gantry crane stability when supposing the load is on the cantilever side.
(Stabilizing moment/overturning moment≥1.25 )
What frame structure should be used？Inverted triangular structure which means the triangle is pointed down by three-line frame composition. Two of which are the main frame, the other for the horizontal line rack
The height of the axis of the frame？Generally it is 1/14 of the span。
The width of the axis of the frame？Generally it is 0.8 times of the axis height of the frame
How many node number of the frame?Generally it is even number. The horizontal angle of the diagonal of a single internode is 40 degrees -45 degrees
Gantry crane design on legs
Gantry crane trolley is running on a bridge, and a lifting trolley is just like a boom-type cranes. Legs on both sides of the bridge are generally rigid legs; when span more than 30 meters, generally on one side, it is the rigid leg, while the other side is flexible leg connected through a ball joint and the bridge, the mast become statically indeterminate system under external loads to avoid outside thrust caused additional stress, it can also compensate bridge vertical temperature deformation gantry cranes wind area, to prevent falling or tipping over the line in the strong wind, and equipped with wind measurement instrument and operation interlock mechanism crane rail clamp.
Gantry crane design on crane ends
Both ends of the bridge can be no cantilever; it can be also at one end or both ends with the cantilever, in order to expand the scope of the necessary working.
Semi-gantry crane at one end there is a leg, the other end of the outrigger, run directly on a high bench.
Types of gantry cranes according to the gantry crane structures:
Full gantry crane systems
Full gantry crane design is the most popular gantry crane system, which —consisted of two legs that ride on crane rail, embedded flush with the top surface of the floor. The full gantry cranes typically run in a straight line in a designated work area. This type of gantry crane design highly utilizes the space underneath of the gantry crane girder between the legs making the scissor lifts, fork lifts, carts, and trucks or other lifting equipment cross the crane possible.