The 4,500/5,500-ton Type 091 (US Department of Defense designation Han-class, Chinese designation 09-I) was the first nuclear-powered submarine (SSN) class deployed by the People's Liberation Army Navy. The first Chief Designer of the submarine was an engineer and scientist of nuclear propulsion engineering Mr. Peng Shilu (彭士禄), then in 1983 succeeded by Mr. Huang Xuhua (黄旭华). The first submarine in the class was commissioned in 1974 and the fifth and final boat of the class was commissioned in 1990. The Han-Class is the among the first generation of nuclear-powered submarines in the People's Liberation Army Navy.