The difference between 321 type steel bridge and 200 type steel bridge

The "321" steel bridge is a fast-assembled bridge developed on the basis of the original British Bailey truss bridge and combined with my country's national conditions and actual conditions. It was finalized and produced in 1965 and has been greatly developed in my country. It is widely used in national defense, combat readiness, and Traffic engineering and municipal water conservancy engineering are widely used assembling bridges in my country. It has the characteristics of simple structure, convenient transportation, quick erection, large load capacity, good interchangeability and strong adaptability. 

The "HD200" type prefabricated highway steel bridge increases the height of the truss, improves the load-bearing capacity, enhances the stability performance, increases the fatigue life, and improves the reliability. Compared with the 321 type steel bridge, under the same combination, the strength is increased by 33%, and the rigidity is doubled. Scope of application: single-lane deck net width, combined span, double-lane deck net width, combined span.