To help a metal fabrication client in Monterrey, Mexico optimize their multi-level workshop workflow, we recently designed and exported a customized 3-ton Single Girder Semi-Gantry Crane. Installed directly beneath an existing 20-ton overhead bridge crane, this semi-gantry system creates an independent, localized material handling workstation without requiring additional building columns on the workshop floor. The order was completed within 18 working days and shipped via containerized ocean freight.
The BMH European-style Semi-Gantry Crane features a 3-ton lifting capacity, a 10-meter span, and a 4.5-meter lifting height under an A5 working classification. Unlike standard gantry cranes that require two ground rails, one side of this semi-gantry crane travels on an elevated runway beam mounted to the existing workshop columns, while the other side runs at floor level using high-strength polyurethane trackless wheels. This trackless bottom-beam configuration keeps the workshop floor completely flat and unobstructed, allowing forklifts and transfer carts to pass freely across the bay.
To ensure synchronized movement between the upper rail wheel and the lower floor-running wheel, our electrical engineers implemented a dual-closed-loop inverter drive system with photoelectric anti-skew sensors. If the crane detects any slight deviation during long travel, the PLC automatically adjusts the speed of the upper or lower drive motor in real time, preventing rail gnawing and structural stress. Safety along the floor travel path is further enhanced by ultrasonic obstacle detection radars, audible-visual warning alarms, and LED safety zone projection lights on the lower end carriage.
The lifting mechanism utilizes a low-headroom European wire rope hoist featuring dual lifting speeds (5/0.8 m/min) and variable frequency cross travel (2–20 m/min). All electrical components were built to match Mexico's 440V, 60Hz, 3-Phase industrial voltage standard. Control is achieved via a lightweight industrial wireless remote transmitter, giving machine operators full freedom to move safely around large welded assemblies.
Prior to shipment, our technical team provided complete 3D layout drawings and wheel load calculation sheets to assist the customer in verifying their existing column brackets. Thanks to modular plug-and-play aviation connectors for the electrical wiring, the customer's local maintenance crew completed on-site mechanical assembly and electrical commissioning in just two days under our remote video guidance.
This semi-gantry crane project illustrates how flexible, space-saving lifting equipment can dramatically improve workstation productivity while eliminating waiting times for main overhead cranes.
