Type 091 Han Class

The Type 091 (or Type 09-I, NATO codename: Han class) is China’s 1st-generation nuclear-powered attack submarine built by Huludao-based Bohai Shipyard. A total of five Type 091 submarines have been constructed between 1967 and 1990, of which three still remain in active service today.


The PLA Navy and Chinese defence industry initiated preliminary research on the nuclear-powered submarine technology in 1958, but the programme was suspended in 1963 due to technical difficulties and financial hardship. The Chinese political leadership took the decision in 1965 to build a land-based nuclear reactor for research and simulation purposes. The PLA Navy drafted a two-phase development plan, to first develop a nuclear-powered attack submarine, upon its success followed by a nuclear-powered missile submarine.

A team of China’s top nuclear scientists and senior government officials was formed in 1969 to lead the nuclear submarine programme. A range of associated facilities were completed by the late 1960s, including the land-based nuclear reactor in Mianyang, Sichuan Province; nuclear submarine shipyard in Huludao, Liaoning Province; and weapon test range for testing torpedo, sonar, and submarine-launched ballistic missile off the east coast. Construction of the first Type 091 nuclear-powered attack submarine Chang Zheng 1(pennant number 1701, later changed to 401) began in 1968. The land-based nuclear reactor became fully operational in 1970 and was ready for installation on the submarine.

Boat 401/Chang Zheng 1 was launched in December 1970 and its nuclear reactor was activated in July 1971. The sea trial began in August 1971 and the submarine was commissioned into the PLA Navy service in August 1974. However, the boat did not achieve initial operational capability for another decade, due to various technical issues and a lack of a suitable torpedo and associated fire-control. The second hull Boat 402/Chang Zheng 2 launched in 1977 suffered from similar issues. Unconfirmed reports suggested that France transferred some technologies in fire-control, sonar and nuclear reactor to China in the mid-1980s to help improve the Type 091.

The Type 091 appears to have bee built in three variants: the basic variant (Boat 401 and 402), the improved variant (Boat 403), and the further improved variant (Boat 404 and 405). From Boat 403/Chang Zheng 3, the submarine’s hull was stretched by 8 m. Boat 401 and 402 received modernisation refit in the late 1980s and was put back in service in the mid-1990s, but they were eventually retired in 2000/01. Boat 403 began mid-life refit in 1998 and was back in service in 2000. All five boats have been deployed by the North Sea Fleet from the Jianggezhuang nuclear submarine base near Qingdao.

The Type 091 utilises a water-drop shape with a double-hulled configuration. The submarine has four stern rudders with a single large 4-blade shaft. The hull has seven watertight compartments, with the sail located above the second compartment. A pair of foreplanes are positioned in the middle of the sail. A number of retractable masts are carried inside the sail including periscopes, radar antennas, radio and satellite communications, and navigation masts. The submarine can fire torpedoes and deploy mines from its six 533 mm torpedo tubes. Boat 404 and 405 can also launch the wire-guided anti-submarine torpedo and the YJ-82 anti-ship cruise missile (ASCM).

The three hulls in active service have received extensive modernisation refit and upgrades, including anechoic tiles and modernised mission systems. They have also been fitted with the technologies originally developed for the next-generation nuclear submarines, such as the H/SQG-207 flank-mounted sonar array and the new 7-blade propeller. However, the submarine is generally regarded as inferior to contemporary U.S. or Russian nuclear submarines in terms of quietness, weapon systems, and sensors.



  • 6x 533 mm torpedo tube, carrying 20 torpedoes or 36 mines
    • Yu-1 (Type 53-51), unguided to 9.2 km at 39 kt or 3.7 km at 51 kt; warhead 400 kg
    • Yu-3 (SET-65E), active/passive homing to 15 km at 40 kt; warhead 205 kg
    • YJ-82 submarine-launched ASCM, active radar-homing, 42 to 80 km range, Mach 0.9 in final approach, 165 kg shaped charge warhead with time-delayed impact proximity fuses

Mission Systems

  • Multi-purpose combat data and command system for submarine control and weapon firing
  • Surface search radar (NATO code name: ‘Snoop Tray’), I-band
  • Type 603/604 bow-mounted, medium-frequency sonar for active/passive search and attack (original)
  • H/SQ2-262 bow-mounted, medium-frequency sonar for active/passive search and attack (modernisation refit)
  • Chinese copy of the French DUUX-5 low frequency sonar, passive ranging and intercept
  • H/SQG-207 flank-mounted sonar array (modernisation refit)
  • Type 921-A radar warning receiver and direction-finder


  • Nuclear with turbo-electric arrangement
  • 1x Pressurised water reactor (PWR) rated at 90MW
  • One shaft with a 4-blade propeller (replaced by a 7-blade propeller after modernisation refit)


  • PLA Designation: Type 091, or Type 09-I
  • NATO code name: Han class
  • Type: Nuclear-powered attack submarine (SSN)
  • Designer: CSIC China Ship Design & Research Centre (701 Institute)
  • Builders: CSIC Bohai Shipbuilding Heavy Industry Co., Ltd.
  • In commission: 1974
  • Number: 5 constructed, 3 in active service
  • Displacement (t): 4,500 (surfaced), 5,500 (dived)
  • Length (m): 106
  • Beam (m): 10
  • Draft (m): 7.4
  • Speed (knots): 12 (surfaced), 25 (dived)
  • Range (nm): N/A
  • Crew: 75


Name            No.    Builder   Fleet   Launched     Commissioned
Chang Zheng 1   401    Bh        NSF     1970-12-26   1974-08-01
Chang Zheng 2   402    Bh        NSF     1977-12-20   1980-12-30
Chang Zheng 3   403    Bh        NSF     1983-10-31   1984-12-25
Chang Zheng 4   404    Bh        NSF     1985-12-26   1987-12-27
Chang Zheng 5   405    Bh        NSF     1990-04      1990-12

Bh.....Bohai Shipuard

NSF....North Sea Fleet


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