The Sinking-1 (沉-1, or Chen-1) naval mine is the fourth type of naval mine entering Chinese service in 1966. It is a bottom mine jointly developed by the 710th research institute, the 152nd Factory and Fengxi Machinery Factory (汾西机器厂), and it was the first Chinese naval mine utilizing an acoustic fuse.
The original article can be found at Chen-1 bottom mine and the edit history here.