The hoisting tonnage of gantry crane refers to the maximum load that the crane can safely lift under certain working conditions. It is affected by the structure, configuration, load distance, lifting height, ground conditions, weather conditions and other factors of the crane. To calculate the lifting tonnage of the gantry crane, it is necessary to measure the size of the triangle formed by the boom, winch and site, and then according to the formula ? (hC)/100. Where, r is the radius between the load and the ground, and hC is the rated moment of the crane. Gantry cranes of different manufacturers and models may have different calculation methods and parameters

There are different types of gantry cranes, which can be divided into the following types according to their installation location, structure and purpose:
The dock gantry crane is installed on the track along the dock for loading and unloading bulk cargo or containers. Common dock gantry cranes include slewing boom type and balanced hydraulic type. Their hoisting tonnage can vary from several tons to 85 tons.
The floating gantry crane is installed on the platform or pontoon and can be moved with the ship for operation on water. Their hoisting tonnage is generally small and suitable for short distance transportation.
The shipborne gantry crane is installed on the deck of the ship and is used for unloading or transferring goods. Their hoisting tonnage depends on the size of the ship and is generally smaller than the portal crane at the wharf.
The slewing jib gantry crane is a common wharf crane, which is composed of a lifting and slewing boom, a tower, a slewing part with machine room, a slowly moving slewing ring bearing, a column, a traveling gantry, drive mechanism and counterweight, etc. 1. Its characteristic is that it can flexibly adjust the load position in the horizontal and vertical directions, and it is suitable for loading and unloading bulk cargo or containers. Its hoisting tonnage varies according to different models, generally between 10-50 tons
The balanced hydraulic gantry crane is a kind of crane that uses the hydraulic system to control the lifting and slewing of the boom. It is characterized by simple structure, flexible operation and convenient maintenance, and is suitable for loading and unloading bulk cargo or containers. Its hoisting tonnage is generally between 10-40 tons.
Gantry crane is a crane installed on the beam between two columns. It can work across the space and is suitable for narrow wharf or warehouse. It has two modes of movement: tire and rail. The lifting tonnage can be large, up to 20000 tons.