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Atago vs Sejong the Great

Atago vs Sejong the Great at a glance — displacement 10,000 vs 10,000 tons, length 165 vs 166 m, speed 30 vs 30 knots, crew 300 vs 300.

Specifications
Atago Sejong the Great
Origin 🇯🇵 Japan 🇰🇷 South Korea
Category Destroyer Destroyer
Type Guided-missile destroyer Guided-missile destroyer
Manufacturer Mitsubishi Heavy Industries Hyundai Heavy Industries
Year introduced 2007 2008
Number built 2 units 4 units
Estimated unit price $1,480 million $923 million
Displacement 10,000 tons 10,000 tons
Maximum speed 30.0 knots 30.0 knots
Range 9,000 nm at 20 knots 5,500 nm at 20 knots
Length 165.0 m 166.0 m
Beam 21.0 m 21.4 m
Crew 300 300
Performance Radar Chart
Armament & Systems
Atago Sejong the Great
Armament
  • 1 × 5-inch (127 mm)/62 Mk 45 Mod 4 gun
  • 8 × Type 90 (SSM-1B) anti-ship missile
  • 2 × 20 mm Phalanx CIWS
  • 2 × HOS-302 triple torpedo tubes (Mark 46 or Type 73 torpedoes)
  • 96-cell Mk 41 Vertical Launching System (SM-2MR, SM-3, VL-ASROC, RIM-162)
  • 1 × 5-inch (127 mm)/L62 caliber Mk 45 Mod 4 naval gun
  • 1 × 30 mm Goalkeeper CIWS
  • 1 × RAM Block 1 CIWS
  • 16 × SSM-700K Haeseong anti-ship missile
  • 2 × triple torpedo tubes for K745 Blue Shark torpedo
  • 80-cell Mk 41 VLS for SM-2 Block IIIB/IV
  • 48-cell K-VLS for K-ASROC Red Shark, Hyunmoo III, K-SAAM, KM-SAM
Propulsion 4 IHI / GE LM2500-30 gas turbines, 100,000 shp (75,000 kW) 4 × General Electric LM2500 COGAG; 2 × shafts; 100,000 shp (75,000 kW) produced power

Detailed Comparison

The Sejong the Great class (KDX-III) of the Republic of Korea Navy (ROKN) and the Atago class of the Japan Maritime Self-Defense Force (JMSDF) constitute the primary Aegis-equipped heavy surface combatants in Northeast Asia. Both designs derive from the US Navy's Arleigh Burke lineage but diverge in armament density, mission prioritization, and hull volume to suit respective national defense strategies.

Development and Design

Commissioned in 2008 and 2007 respectively, both classes exceed 10,000 tons full load displacement. The Sejong the Great class, built by Hyundai Heavy Industries, was developed under the KDX-III program to transition the ROKN to a blue-water force. The Atago class, constructed by Mitsubishi Heavy Industries, serves as a scaled-up Kongō class with added helicopter facilities and reduced radar cross-section features, including a plain-structure mast. While the Atago features a standard Mk 41 VLS configuration, the South Korean vessel utilizes a larger hull volume to accommodate a hybrid VLS arrangement, resulting in a higher displacement.

Weapons and Sensors

Armament density defines the Sejong the Great class, which carries 128 VLS cells compared to the Atago's 96. The ROKN vessel combines 80 Mk 41 cells for SM-2s with 48 domestic K-VLS cells for indigenous assets, including the Red Shark ASROC and Hyunmoo III land-attack cruise missiles. The Atago relies exclusively on the Mk 41 VLS for SM-2, VL-ASROC, and SM-3 BMD interceptors. Anti-surface warfare capabilities favor the Korean platform, which mounts 16 SSM-700K missiles versus 8 Type 90 missiles on the Japanese ship. Both utilize the AN/SPY-1D(V) radar; however, Atago vessels have received Aegis Baseline 9 upgrades specifically for integrated air and ballistic missile defense (BMD). Sejong Batch I ships operate on Baseline 7.1, with Batch II introducing Baseline 9.C2.

Propulsion and Performance

Both classes employ a Combined Gas and Gas (COGAG) arrangement with four General Electric LM2500 turbines generating 100,000 shp. Top speeds are identical at 30 knots. The Atago class possesses greater operational endurance with a range of 9,000 nm at 20 knots, compared to 5,500 nm for the Sejong the Great. In aviation support, the ROKN design provides hangar space for two Super Lynx or Seahawk helicopters, whereas the JMSDF design accommodates a single SH-60K.

Deployment and Combat Record

The ROKN operates three Batch I units, with the lead ship tracking North Korean long-range missile launches shortly after commissioning. A second batch, starting with Jeongjo the Great (2024), is currently entering service to enhance BMD capabilities. The JMSDF operates two Atago class vessels, stationed at Maizuru and Sasebo, tasked primarily with fleet air defense and ballistic missile interception. The Atago class production ceased at two units, succeeded by the Maya class.

Conclusion

The Sejong the Great class prioritizes offensive volume and multi-role versatility, evidenced by its land-attack capability and larger missile magazine. Conversely, the Atago class reflects a defensive doctrine focused on endurance and ballistic missile defense integration within the US-Japan security framework.

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Frequently Asked Questions

Which has greater displacement, the Atago-class or Sejong the Great-class?
The Sejong the Great-class has greater displacement at 10,000 tons compared to the Atago-class's 10,000 tons.
Which is faster, the Atago-class or Sejong the Great-class?
The Sejong the Great-class is faster with a maximum speed of 30 knots compared to the Atago-class's 30 knots.
Which has longer range, the Atago-class or Sejong the Great-class?
The Atago-class has a longer range at 9,000 nautical miles compared to the Sejong the Great-class's 5,500 nautical miles.
Which is longer, the Atago-class or Sejong the Great-class?
The Sejong the Great-class is longer at 166.0 meters compared to the Atago-class's 165.0 meters.
How many crew members do the Atago-class and Sejong the Great-class have?
The Sejong the Great-class has a larger crew complement of 300 compared to the Atago-class's 300 crew members.
Which is more expensive, the Atago-class or Sejong the Great-class?
The Atago-class is more expensive at approximately $1.5 billion per unit compared to the Sejong the Great-class at $923 million.
Which has been built in greater numbers, the Atago-class or Sejong the Great-class?
The Sejong the Great-class has been built in greater numbers with 4 vessels compared to 2 vessels of the Atago-class.