Gantry cranes are mostly horizontal luffing system

Steel factory equipment  the weight and center of gravity of each boom system luffing process is almost no vertical displacement. One way is by adding events counterweight to balance the lifting boom system changes the center of gravity of the pitch synthesis when this method is more convenient arrangement, work is also more reliable and widely used. The semi gantry cranes second method is to rely on institutional characteristics of the boom system to ensure that the movement trajectory when the center of gravity close to the level luffing synthesis, No activity counterweight.

Crane supplier  along the trajectory of the heavy lifting to move closer to the horizon in the luffing process, compensation methods and compositions can be used boom law. Compensation Act by the special storage system automatically retractable rope hoisting rope luffing appropriate process to compensate boom lift spreader vertical displacement caused. Arm method is to rely on institutional characteristics guarantee Arm arm ends move closer level luffing process. Both methods are widely used.