The container gantry crane is a highly efficient and reliable solution for handling, transporting, and stacking containers in modern container yards. Designed to operate along fixed rails, it enables smooth lifting and precise placement of containers within the designated working area, ensuring safe and organized yard operations.
Equipped with advanced AC frequency conversion control, the container gantry crane achieves accurate speed regulation for the hoisting, trolley traveling, and crane traveling mechanisms. This allows smooth acceleration and deceleration, reduces mechanical impact, and improves overall operational efficiency.
The hoisting mechanism is commonly designed with a single-drum configuration for standard container handling requirements. Depending on operational needs and load conditions, a double-drum hoisting system can also be adopted to enhance lifting stability and meet higher performance demands, making the crane adaptable to a wide range of container handling applications.
Main Components
♦Gantry Frame: The gantry frame is the main structural body and primary load-bearing component of the heavy duty gantry crane. It consists of main girders, support legs, end beams, lower beams, trolley frames, and various auxiliary steel structures. Additional elements such as the operator’s cab, walkways, ladders, railings, and maintenance platforms are integrated into the frame design. The gantry frame is engineered to provide sufficient stiffness, strength, and overall stability under dynamic and static loads, ensuring safe crane operation in demanding port environments.
♦Lifting Trolley: The lifting trolley is composed of the hoisting mechanism, trolley traveling mechanism, and trolley frame. The trolley frame is a welded, box-type steel structure with an integrated rain shelter. It is equipped with multiple safety devices, including buffers, rail sweepers, limit stops, and operational limiters. The hoisting system includes a load limiter, load display, and several safety interlock switches. Wheel diameter and material are carefully selected to withstand maximum wheel loads under the most unfavorable operating conditions, preventing wheel overloading.
♦Trolley Traveling Mechanism: The trolley traveling mechanism of the heavy duty gantry crane includes the drive unit, auxiliary traveling devices, and safety protection systems. It adopts an articulated balanced beam structure to ensure equal wheel pressure under the same support leg. Each drive unit independently drives a single wheel without exposed gear transmission. Safety features include wind-proof anchoring devices, track cleaners, polyurethane buffers, and wheel shaft break protection installed on every pair of traveling wheels.
♦Mobile Operator’s Cab: The operator’s cab is rigidly mounted to the trolley and travels together with it, reducing the risk of collision with container stacks or spreaders. The cab uses enclosed, heat-insulated toughened glass, offering excellent visibility, comfort, and thermal performance. Its design prioritizes safety, durability, ergonomic comfort, and aesthetic appearance to reduce operator fatigue during long working hours.
♦Electrical Protection System: The electrical system includes main circuit breakers, power contactors, and comprehensive protection devices such as short-circuit protection, overcurrent protection, voltage loss protection, overload protection, limit switches, emergency stop devices, electrical interlocking, warning alarms, anemometers, and lightning protection systems.
♦Platforms and Ladders: Access ladders, platforms, and walkways are constructed using high-strength bolted connections. Anti-slip checkered steel plates or galvanized steel gratings (typically 3 mm thick) are used to ensure safe access for operation and maintenance personnel.
♦Container Spreader: The container spreader of the heavy duty gantry crane is selected based on the container types to be handled, such as 20 ft, 40 ft, or 45 ft containers. It is designed for quick and easy replacement, allowing flexible adaptation to different container handling requirements.
Features of the Container Gantry Crane
Low Hoisting Speed with High Trolley Traveling Speed
Container gantry cranes are designed to meet the specific operational requirements of container terminals. Since containers are typically stacked three-high over four or four-high over five, the required lifting height is relatively limited. As a result, the hoisting speed is designed to be lower. In contrast, container yards are usually long and narrow along the rail direction, requiring a higher trolley traveling speed to maintain efficient handling capacity and high productivity.
Optimized Speed Based on Span and Cantilever Length
The trolley traveling speed is determined by the bridge span and cantilever length. When the span and cantilever are relatively small, the demand for high traveling speed is lower. For cranes with larger spans and longer cantilevers, the trolley speed is increased accordingly to meet higher throughput and operational efficiency requirements.
Synchronous Travel Control for Large Spans
When the container gantry crane span exceeds 40 meters, differences in rolling resistance between the two gantry legs may cause misalignment during high-speed travel. To prevent this, a synchronization system is installed. Through electrical control, the traveling mechanisms on both sides are kept synchronized, ensuring smooth, stable, and safe crane movement.
Advanced Electrical Drive and Control System
To meet high-performance operating requirements, the electrical drive system adopts thyristor DC drive or AC variable-speed control systems, providing precise speed regulation and smooth operation. Alternative systems such as AC eddy current control or stator voltage regulation may also be used. For high-speed trolley mechanisms, electrical braking functions are integrated to reduce mechanical impact, improve safety, and enhance the overall service life of the container gantry crane.
