Kilo class

China purchased 12 Project 877EKM/636 (NATO reporting name: Kilo class) conventionally-powered diesel-electric submarines (SSK) from Russia between 1995 and 2007. The acquisition of these submarines provided the PLA Navy with access to the latest submarine quieting, sonar and weapon technologies, some of which have reportedly been incorporated into the indigenous Type 039A (Yuan class).


The Kilo class is designed by St. Petersburg-based Rubin Central Maritime Design Bureau, intended mainly for anti-submarine warfare (ASW) and anti-surface warfare (ASuW) roles, and also capable of general reconnaissance, water mine laying and patrol missions. There are three variants in the Russian Navy service: Project 877, Project 877K, and Project 877M. The Project 877EKM was the early export variant with reduced features. The Project 636 is a follow-on development of the former with reduced noise level and increased underwater speed.

The PLA Navy ordered two Project 877EKM submarines from Russia in 1994, and took delivery of them in 1995. An order was placed in 1996 for two additional Kilo submarines in the improved Project 636 variant, making the PLA Navy its first international customer. The delivery of these submarines took place in 1997 and 1998. All four Kilo submarines have been deployed by the PLA Navy East Sea Fleet at the submarine base in Zhoushan, Zhejiang Province facing the Taiwan Strait.

In 2002, the PLA Navy signed a US$1.5 billion deal with the Russian state arms export agency Rosoboronoexport to purchase eight more Project 636M submarines. In May 2002, the Russian news agency Itar-Tass confirmed that construction on the first two hulls of these submarines was to commence during the first quarter of 2003 at the Severodvinsk Shipyard. The remaining six hulls were to be built at Admiralteyskiye Verfi Shipyard in St. Petersburg (five hulls) and at Krasnoye Sormovo Shipyard in Nizhniy Novgorod (one hull). Delivery of these submarine began in 2005 and was completed by 2007.

In the early years of operating the Kilo submarines, the PLA Navy reportedly experienced some mechanical problems due to insufficient crew training, and more constantly because of the material problems including the troublesome batteries and generators. The first two Project 877EKM submarines were said to be out of operation for several months due to technical problems. As the PLA Navy became more efficient in operating the submarine, these problems were subsequently solved.

The purchase of additional Kilo submarines reflected the PLA Navy’s urgency in building a modernised underwater force that capable of supporting its military actions against Taiwan and deterring any intervention by the U.S. Navy. It also reflects the incapability of China’s indigenous shipbuilding industry to fulfil the navy’s requirements, which forced the Chinese military planners to look elsewhere for a solution.

The Kilo class features a water-drop shape double hull with a T-shape stern rudder and a single large shaft. A pair of bow planes are located close to the midship on the upper hull in front of the sail. With a reserve buoyancy of 32%, the submarine consists of six watertight compartments separated by transverse bulkhead in a pressured double hull, which increases the survivability of the submarine, even with one compartment and adjacent ballast tanks flooded. The command and control and fire-control systems are located in the main control room which is sealed off from other compartments.

To reduce the submarine’s acoustic signature, the flooding ports are removed from the forebody, and the hull is covered with rubber anechoic tile to reduce its noise level. The improved Project 636 has more powerful diesel generators, but with a lowered speed main shaft, which provides a substantial reduction in the acoustic signature of the submarine.

The Project 877EKM has a displacement of 2,300 t when surfaced and 3,950 t submerged. The Project 636 has an extended hull with slightly larger displacement. The maximum diving depth is 300 m. The surface speed is 11 knots and the underwater speed is 20 knots. The personnel onboard total 52, and the submarine has an endurance at sea of 45 days.

The submarine’s propulsion system consists of two diesel generators, a main propulsion motor, a fuel-economic motor and a single shaft driving a seven-blade fixed-pitch propeller. There are two additional stand-by motors for running in shallow waters, at mooring and in cases of emergency. Two 120-cell storage batteries are installed in the first and third compartments of the submarine. The main machinery is equipped with an automatic control system.



  • 6x 533 mm torpedo tube (2 top, 4 below), carrying 18 torpedoes (6 in launch tubes and 12 on weapon racks) or 24 mines. The two outbound tubes at the bottom can launch TEST-71MKE TV electric homing torpedoes. The two upper tubes can launch the 3M-54E anti-ship cruise missile
    • TEST-71MKE anti-submarine torpedo, active sonar homing with TV guidance, remotely-controlled by operator to manually switch to an alternative target or manoeuvre in two axes; 1,820 kg total mass; 205 kg warhead
    • 53-65KE anti-surface torpedo, wake-homing; 2,200 kg total mass; 200kg warhead; up to 40 km range; up to 500 m depth of search
    • (later 8 Project 636Ms) Klub-S missile complex / Novator 3M-54E Kalibr (SS-N-27 ‘Sizzler’) anti-ship cruise missile; Inertial Navigation System (INS) with active radar-homing; up to 220 km range; 450 kg high-explosive warhead
    • 24x mines in lieu of torpedoes
  • 8x Strela-3 (SA-N-8 ‘Gremlin’) surface-to-air missiles (may have not been installed on those in service with the PLA Navy)

Mission Systems

  • (Project 877EKM) Multi-purpose combat information system
    • MVU-110EM computer allowing 5 targets to be tracked simultaneously, with 2 automatically and three manually
    • Andoga navigation system feeding the course and speed data into the combat data system
  • (Project 636) Improved C4ISR system with high-speed computer capable of processing information from the surveillance equipment and displaying it on the screen. It can also automatically determine the surface and underwater target data and calculate firing parameters, provide automatic fire control, and provide information and recommendation on the manoeuvres and deployment of weapons.
  • (Project 877EKM) MGK-400 Rubikon (Shark Teech) dual-channel sonar providing echo target ranging, detection of active sonar signals, and underwater communication
  • (Project 636) MGK-400EM digital sonar
  • MRK-50 (Snoop Tray-2) active surface search radar working in periscope and surface modes to provide information on the underwater and air situation, radar identification, and navigational safety
  • Countermeasures include electronic support measures (ESM)
  • Radar warning receiver
  • Direction-finder


  • 2x diesel generators
  • 1x main propulsion motor
  • 1x fuel-economic motor
  • One shaft with a single 7-blade fixed-pitch propeller


  • Manufacturer designation: Project 877EKM/636
  • NATO code name: Kilo class
  • Type: Diesel-electric attack submarine (SSK)
  • Designer: St. Petersburg-based Rubin Central Maritime Design Bureau
  • Builders: Severodvinsk Shipyard; Admiralteyskiye Verfi Shipyard (St. Petersburg); Krasnoye Sormovo Shipyard (Nizhniy Novgorod)
  • In commission: 1995
  • Number: 12
  • Displacement (t): (Project 877EKM/636) 2,300/2,350 (surfaced); 3,950/4,000 (dived)
  • Length (m): (Project 877EKM) 72.9; (Project 636) 73.8
  • Beam (m): 9.9
  • Draft (m): 6.3
  • Speed (knots): 11 (surfaced); 20 (dived)
  • Design depth (m): 240 to 300
  • Self-sustaining capability (days): 45
  • Range (nm): N/A
  • Crew: 52


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