Tianjin is China's largest city that most Americans have never even heard of, only about 30 minutes to the east of Beijing by high speed rail. The city is nearly as big as Beijing, and its harbor is the main shipping port for the north of China. en.wikipedia.org/wiki/Port_of_Tianjin
This boat tour covered only a small harbor out of the larger port layout. You can see many more loading cranes off in the distance in pretty much every direction. There is a good deal of raw material traffic here in addition to the container shipping. The port is actually in a different city called Tanggu, but the entire region exists as one megalopolis and visitors like us can hardly tell where one administrative zone ends and another begins, even though these differences can be important to those who live there, of course.