The double girder overhead travelling crane is the type of overhead crane used for large loads and / or large openings. These bridges consist of two main beams, on whose upper part the hoist is moved, the lifting of the loads is carried out with the hook between the two beams. They run on the treadway fixed to the pylons of the building if they have been designed with consoles designed for this purpose. If not, it is necessary to execute a metal structure independent of the structure of the building, to support the rolling path. The equipment of the rolling bridge is made with a steel rope hoist. It is the right choice if you want to load up to 80 tons or more.