China’s Grand Canal climbs 42 metres with Song pound locks
The Jing–Hang Grand Canal links Beijing to Hangzhou across roughly 1,776 kilometres of rivers and lakes—the spine of medieval China’s north–south grain and troop moves. Its highest reach, 42 metres above sea level in Shandong foothills, became routine after Qiao Weiyue’s tenth-century pound lock.
The oldest cuts date to the early fifth century BCE, when King Fuchai of Wu ordered a northern channel for campaigns against Qi and for trade. An even older waterway, the Honggou or Wild Geese canal, already linked the Si and Bian rivers with the Yellow River close to Kaifeng and served as a model for later trunks.
After the Sui reunified China, engineer Liang Rui’s levee project on the Yellow River in 587 added lock gates to control canal levels, with double slipways to drag boats over when the drop was too great for a flash lock. Emperor Yang finished the system between 604 and 609, first linking his southern capital Yangzhou to Luoyang by the Tongji Canal, then running southeast to Suzhou and Hangzhou. It was still a patchwork of artificial and natural channels, shadowed by an imperial road.
Under the Tang, branches reached Chang’an, yet it was canal-side Yangzhou, seat of the salt monopoly, that became the economic hub. By 735 about 165,000 short tons of grain moved along the canal each year, and the government built granaries along the route in case floods cut it. After the An Lushan rebellion of 755–763 the northern economy never fully recovered, and in 858 a huge flood along the canal drowned thousands of acres of farmland.
In the tenth century Qiao Weiyue (926–1001) devised the pound lock, which let barges climb safely to the canal’s highest stretch in the Shandong hills. Silting later forced route changes, and today’s Beijing–Hangzhou main stem of about 1,776 km is divided into six sections.
Source: Grand Canal (China)
