Foundry bridge cranes are the primary lifting and transportation equipment in steel mills’ smelting workshops, used for operations such as transferring liquid metal, pouring, and adding molten iron during the smelting process. Cranes under 125t typically feature a YZ-type double-girder structure. Cranes over 125t typically feature a YZS-type four-girder structure. The YZS-type utilizes a four-beam, four-track, dual-trolley design. It primarily consists of a bridge, main trolley, auxiliary trolley, hook beam, trolley travel, and electrical components. The main trolley operates on the main girder track outside the bridge, while the auxiliary trolley operates on the auxiliary girder track inside the bridge. The main trolley’s pickup mechanism utilizes fixed-spaced hook beams.