Gantry Crane Box Girder

Box girder crane is widely used in the industry to upload goods or materials. Box girder cranes have an excellent weight-to-span length ratio compared to typical cranes. This feature greatly reduces the cost of steel construction projects.

The box girder serves as the primary load-bearing structure of a gantry crane, composed of upper / lower cover plates, web plates, and internal stiffening plates. These components are typically fabricated from high-strength steel grades such as ASTM A36, S355JR, or Q355B, selected for their durability and weldability. The steel plates undergo special surface pre-treatment (dark red appearance), to prevent corrosion and extend the crane's service life.

For large-span cranes, the box girder incorporates many stiffening plates to:

1. Reinforce structural integrity by distributing loads between the cover plates and webs.
2. Transfer trolley forces evenly to the web plates during operation, minimizing localized stress.

After welding and assembly, the box girder undergoes SA2.5 shot blasting to remove impurities and create an optimal surface for protective paint adhesion, ensuring long-term resistance.

Box girder crane has key characteristics of long spans and higher capacity. Because less steel is used in the fabrication of box girder cranes, and also maintains its robustness. Therefore, box girder cranes are the best choice when the crane load exceeds 30t or the span exceeds 60 feet.

Box girder crane has become an important component in modern steel building construction. SYNERGIA's box girder bridge cranes are fabricated by AWS D1.1 certified welders and designed specifically for your projects. Get in touch with our experts for more information.