Cloud Ladder Siege Engine

Timeline

1. c. -500–-221Central Plains · HenanDuring the Warring States period states built fortified cities and the cloud ladder became standard siege equipment. Mozi's 'Preparation Against Scaling Ladders' details its structure and defensive countermeasures (fire attack, pushing ladders, grappling hooks), showing that cloud ladders already came in fixed ladders, flying ladders, and multi-tiered ranks requiring many men to push them against the wall.
2. 200–1279Kaifeng · KaifengMilitary texts from the Han and Tang onward (such as Tongdian's military chapter and Wujing Zongyao) record the dimensions and use of cloud ladders, flying ladders, and ranked ladders, employed with tower vehicles and stone-throwing. In the Song, city wall heights and barbican systems were perfected, requiring longer ladder bodies and flank cover, often used together with fire arrows and fire balls.
3. 1351–1368Yingzhou · FuyangFrom 1341 to 1350 the Yuan court's governance crisis deepened, and rebel forces and warlords frequently besieged cities. After the Red Turban uprising in the eleventh Zhizheng year (1351), besieging forces still used cloud ladders, battering rams, and tunnels together to breach prefectural walls; historical records of many battles mention scaling ladders against Yuan firearms and crossbow bolts.
4. 1368–1600Nanjing · NanjingIn the early Ming, cloud ladders were still built to standards such as those in the Wubei Zhi, used together with falconets and matchlocks to cover scaling troops. After the 16th century, bastion-style firearm defenses rose and the cloud ladder's central role in major sieges gradually declined, though it was still occasionally used in attacks on inland prefectural cities.