Southern Song Paddle-Wheel Warships (Chechuan)

Timeline

1. 1132De'an Prefecture · Jiangzhou CircuitHan Shizhong led naval forces attacking the Jin with chechuan (paddle-wheel warships); soldiers treaded wheels driving the paddle blades on both sides, the ships moving like the wind, and in coordination with fire attacks crushing a Jin detachment under Wuzhu, demonstrating overwhelming maneuverability on inland waters.
2. 1135–1141Yangtze River section at Nanjing · Lower YangtzeIn the battles of Huangtiandang and Caishi Rock, the Southern Song navy used large numbers of chechuan to surround Jin river-crossing fleets; combined with tower ships and sea-hawk ships, they became standard equipment in Song-Jin naval engagements.
3. 1201–1210Jianghuai defense line · HuaixiAround the Kaixi Northern Expedition, the Southern Song deployed chechuan navies on the Yangtze and Huai rivers for patrol, troop transport, and assault; some large chechuan carried ballistae and fire weapons, forming the mainstay of the river-defense fleet.
4. c. 1250–1279Lin'an Naval Command · Southern SongLate Southern Song chechuan grew larger and standardized, with more treadwheel crew and better paddle-wheel protection; the technique passed to the Yuan and Ming, influencing paddle-wheel design of grain-transport and war vessels, an important precursor to the modern steam paddle wheel.