Su Song's Astronomical Clock Tower
1088 CE · Medieval
In 1088, Chinese polymath Su Song completed a wooden pilot model of a 40-foot tall water-powered astronomical clock tower in Kaifeng during the Northern Song dynasty. The device combined timekeeping with astronomical observations and featured an escapement mechanism, armillary sphere, celestial globe, and 133 mechanized mannequins that announced hours. Su Song completed the bronze version by 1094. The clock incorporated the first known endless power-transmitting chain drive. Jurchen invaders destroyed the device in 1127, dismantling and removing it to Beijing where they could not reassemble it. Su Song documented the design in his 1092 treatise 'Xinyi Xiangfayao.'
Key Figures
Yi XingSu SongHan Gonglian
Locations
Kaifeng
Topics
astronomymechanical engineeringclockSong dynastywater power
Connected Events — 2 Connections
Chinese water-powered automation techniques documented in Su Song astronomical clock treatise were transmitted westward along Silk Road routes, influencing al-Jazari designs Elephant Clock Invented
Yi Xing's pioneering escapement mechanism provided the foundational technology that Su Song directly incorporated and refined in his astronomical clock tower 363 years later, enabling precise timekeeping combined with astronomical observation Yi Xing's Water-Driven Escapement Mechanism
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