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Najin vs Sariwon

Najin vs Sariwon at a glance — displacement 1,600 vs 650 tons, length 100 vs 61 m, speed 26 vs 16 knots.

Specifications
Najin Sariwon
Origin 🇰🇵 North Korea 🇰🇵 North Korea
Category Frigate Corvette
Type Frigate Corvette
Manufacturer Najin Shipyard Mayang-do or Bong Dao Bo shipyards
Year introduced 1973 1965
Number built 4 units 5 units
Estimated unit price NA NA
Displacement 1,600 tons 650 tons
Maximum speed 26.0 knots 16.0 knots
Range 4,000 nm at 14 knots 2,700 nm at 16 knots
Length 100.0 m 61.5 m
Beam 10.0 m 7.5 m
Crew 180 --
Performance Radar Chart
Armament & Systems
Najin Sariwon
Armament
  • 2 × SS-N-2 Styx (later Kh-35) anti-ship missiles
  • 2 × 100 mm guns
  • 4 × 57 mm guns (2 twin)
  • 30 mm and 25 mm anti-aircraft guns
  • 2 × RBU-1200 anti-submarine rocket launchers
  • Depth charges and up to 30 mines
  • 4 × 57 mm guns (2 twin)
  • 4 × 37 mm guns (2 twin)
  • 16 × 14.5 mm machine guns (4 quad)
  • 2 × depth charge rails
  • Up to 30 mines
Propulsion 2 diesel engines, 15,000 bhp, 2 shafts 2 diesel engines

Detailed Comparison

The Korean People’s Navy (KPN) relies heavily on a rapidly aging surface fleet, maintaining legacy hulls through continuous piecemeal upgrades. The 1,600-ton Najin-class frigate and the 650-ton Sariwon-class corvette exemplify the stagnation of North Korea’s conventional large-surface combatant programs, predating the current doctrine of asymmetric submarine and fast-attack missile forces.

Development and Design

Built between 1971 and 1979 at the Najin shipyards, the four Najin-class frigates visually replicate the Soviet Project 42 (Kola) class but utilize a distinct indigenous hull. The five Sariwon-class corvettes predate them, constructed in the 1960s at Mayang-do and Bong Dao Bo. Their design is a direct continuation of the Soviet Fugas (Tral) class fleet minesweepers from the 1930s. Both designs lack modern survivability measures, compartmentalization standards, or radar cross-section (RCS) mitigation.

Weapons and Sensors

The Najin possesses over-the-horizon strike capability, whereas the Sariwon is restricted to visual-range engagements.

Najin armament evolution:

  • Initially armed with 100mm/57mm guns and torpedoes.
  • Mid-1980s refit added P-15 Termit anti-ship missiles scavenged from Osa-class boats. The launchers were poorly integrated, creating severe top-weight issues and a high risk of catastrophic secondary explosions.
  • A 2014 modernization on at least one hull replaced the Termits with Kh-35 (Kumsong-3) anti-ship missiles and added twin 30mm automated turrets derived from the AK-630 close-in weapon system.

The Sariwon is entirely gun-armed, mounting four 57mm, four 37mm, and sixteen 14.5mm heavy machine guns. Both classes retain a minelaying capacity of approximately 30 mines, relying on obsolete Soviet-era surface search radars (such as Pot Head or Skin Head) and hull-mounted sonars with negligible utility against modern quiet submarines.

Propulsion and Performance

The Najin utilizes two diesel engines generating 15,000 bhp on two shafts, yielding a top speed of 26 knots and a 4,000-nautical-mile range at 14 knots. The Sariwon operates on two diesels producing a maximum speed of 16 knots and a 2,700-nautical-mile range. The Sariwon’s 16-knot top speed restricts it exclusively to static coastal defense or pre-planned minelaying operations, as it cannot intercept modern naval or commercial traffic.

Deployment and Combat Record

Neither class actively participates in KPN frontline skirmishes. During Northern Limit Line (NLL) clashes, such as the Battles of Yeonpyeong (1999, 2002), the KPN deployed expendable patrol boats and torpedo craft. The Sariwon units remain stationed on the East Coast for fishery patrol and localized escort. The Najin hulls serve primarily as fleet flagships and propaganda assets; deploying them within range of Republic of Korea Navy (ROKN) coastal defense cruise missiles or air assets would result in rapid loss.

Conclusion

The modernized Najin-class frigate holds a definitive tactical edge over the Sariwon. The integration of Kh-35 missiles and 30mm CIWS provides the Najin with standoff anti-ship lethality and point defense, whereas the Sariwon is functionally a 1930s minesweeper lacking anti-ship missiles, anti-air tracking, or the speed to evade targeting. In a conventional conflict, both ships would act solely as localized minelayers or stationary batteries before being neutralized by ROKN precision fires.

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Frequently Asked Questions

Which has greater displacement, the Najin-class or Sariwon-class?
The Najin-class has greater displacement at 1,600 tons compared to the Sariwon-class's 650 tons.
Which is faster, the Najin-class or Sariwon-class?
The Najin-class is faster with a maximum speed of 26 knots compared to the Sariwon-class's 16 knots.
Which has longer range, the Najin-class or Sariwon-class?
The Najin-class has a longer range at 4,000 nautical miles compared to the Sariwon-class's 2,700 nautical miles.
Which is longer, the Najin-class or Sariwon-class?
The Najin-class is longer at 100.0 meters compared to the Sariwon-class's 61.5 meters.
Which has been built in greater numbers, the Najin-class or Sariwon-class?
The Sariwon-class has been built in greater numbers with 5 vessels compared to 4 vessels of the Najin-class.