Gantry Crane
A welded structure made from angle sections or I-beams.
Product description
Main girder structures
1. Truss girder
A welded structure made from angle sections or I-beams. It offers low cost, low self-weight and good wind resistance. However, the numerous welds and inherent truss limitations lead to greater deflection, lower stiffness, relatively lower reliability and frequent weld inspection. It is suitable for sites with lower safety requirements and smaller lifting loads.
2. Box girder
Steel plates are welded into a box section with high safety and stiffness. It is generally used on large and ultra-large-capacity gantry cranes. An MGhz1200 crane is cited with a 1,200-tonne capacity and a box-section main girder. Drawbacks include high cost, high self-weight and poorer wind resistance.
3. Honeycomb girder
Usually an isosceles-triangular honeycomb girder: a triangular cross-section, perforated inclined webs on both sides, and upper and lower chords. It combines features of truss and box girders, providing greater stiffness, less deflection and higher reliability than a truss. Welding steel plates also makes it somewhat heavier and more expensive than a truss. It suits frequent use or heavy lifting at work sites and girder yards.
