A seawall is an embankment built along a coast or riverbank to hold back the tide. The old Qiantang seawalls are the model of stone-built walls, guarding the farmland behind them.
The building of the wall went in three broad steps. In the Five Dynasties, stone in bamboo cages and timber piles for the base were used, and the Qiantang wall moved from earth to stone; in the Northern Song the wall was built of dressed stone, with men assigned to keep it in repair; and in the Qing, under Qianlong, the fish-scale stone wall was spread, its stones laid in alternating headers and stretchers, in courses, and tied with iron clamps, and it became the standard form of the Qiantang wall.
The safety of Jiangnan's farming rested on this wall holding.
Stone Seawall Engineering is the class in the chapter on Infrastructure on the stone seawalls that hold back the tide along the Qiantang River. From the bamboo cages of stone of the Five Dynasties, to the dressed-stone wall of the Northern Song, to the fish-scale stone walls of the Qing, the way the wall was built changed step by step, guarding the farmland of Jiangnan.
