The fourth cross-sea bridge in Macao is located on the east side of the Macao Friendship Bridge, connecting the Macao Peninsula and Taipa Island. The steel structure of the bridge is in the form of truss and steel box girder. The total weight of the steel structure undertaken by CRBBG is about 37000 tons. The standards of raw materials are Q420qD, Q500qD and Q690qD. The standard section of the steel girder of the south main bridge is 46.2m wide and 2.96m high. The structural form of the steel girder of the south approach bridge is similar to that of the box girder of the south main bridge. The processing technical requirements, manufacturing acceptance specifications and on-site welding and coating requirements of the bridge steel structure shall be strictly implemented in accordance with BS 5400-6, EN1090-2 EXC3, JT/T 722 standards. The scope of work of CRBBG includes raw material procurement, shopdrawing, plate unit production and manufacturing, assembly, coating, delivery to construction site, welding on-site, repainting of paint.