Qingdao Beihai Shipbuilding Industry Co., Ltd. is a large shipbuilding and repairing company controlled by China Shipbuilding Industry Corporation (CSIC). The company relocated to Haixi Bay in Qingdao Economic and Technological Development Zone in 2004 to build a shipbuilding and repairing base in Qingdao West Bay. Shenyang Baotong Door Industry Co., Ltd. undertook the construction of its supporting gate project at the base shipbuilding area factory. The door adopts a flexible lifting gate with a width of 35 meters and a height of 12 meters; a width of 29.2 meters and a height of 16 meters, totaling 12 mm.