Atago-class destroyer

Atago-class destroyer
Ashigara (DDG-178)
Class overview
Builders:	Mitsubishi Heavy Industries
Operators:	Japan Maritime Self-Defense Force
Preceded by:	Kongō-class destroyer
Cost:	¥140 billion $1.48 billion (constant 2009 USD)
Built:	2004–2008
In commission:	2007–
Completed:	2
Active:	2
General characteristics
Type:	Guided missile destroyer
Displacement:	7,700 tons standard 10,000+ tons full load
Length:	165 m (541 ft 4 in)
Beam:	21 m (68 ft 11 in)
Draft:	6.2 m (20 ft 4 in)
Propulsion:	4 Ishikawajima Harima/General Electric LM2500-30 gas turbines Two shafts 5-bladed CP props 100,000 shaft horsepower (75 MW)
Speed:	30 knots (56 km/h)
Boats & landing craft carried:	1 Rigid hull inflatable boat
Complement:	300
Sensors and processing systems:	AN/SPY-1D(V) radar OPS-28E surface search radar AN/SQS-53C sonar 3 x AN/SPG-62 FCS AN/SQQ-89 Mk 46 Optronic director Mk 160 FCS Mk 116 FCS
Electronic warfare & decoys:	ESM/ECM：NOLQ-2 4 x Mark 36 SRBOC
Armament:	• RGM-84 Harpoon SSM • SM-2MR Standard SAM (64 cells at the bow, 32 cell at the aft) • SM-3 Block IA ABM • RUM-139 Vertical Launch ASROC • 1 x 5 inch (127 mm) / 62 caliber Mark 45 mod 4 • 2 x 20 mm Phalanx CIWS • 2 x Type 68 triple torpedo tubes (6 x Mk-46 or Type 73 torpedoes)
Aircraft carried:	1 × SH-60K helicopter
Aviation facilities:	Flight deck and enclosed hangar for one helicopter

The Atago class of guided missile destroyer (あたご型護衛艦｜atago-gata-go-ei-kan) is an improved version of the Japan Maritime Self-Defense Force (JMSDF)'s Kongō class destroyers. It is a Japanese variant of the United States Navy Arleigh Burke-class destroyer (Flight IIA).

Both ships of the class share a same name with Japanese World War II cruisers. On occasion, Atago class destroyers have been incorrectly referred to as cruisers by the Japanese media.

Design

JDS Kongo with Ashigara while under construction at Mitsubishi in Nagasaki.

In 2000, the Japan Defense Agency Maritime Staff Office included another two Aegis ships in its five-year budget on top of the four Kongo class destroyers originally ordered.

The Atago class is fundamentally an improved and scaled up version of Kongō class destroyers. It features large accommodation and capable of flexible operation. One of the most obvious changes is an additional hangar to carry one SH-60K helicopter. In comparison to the Kongō-class/Arleigh Burke-class (Flight I) which only had helicopter platforms (but no support equipment), these ships have better helicopter handling facilities. To enhance Atago class' function as command centers, the bridge is two floors higher than Arleigh Burke-class Flight IIA, making her full load displacement over 10,000 tons—the first time for a JMSDF surface combat vessel. The gun caliber has extended from the 54 caliber of the Kongō class to the 62 caliber with strengthened powder charge capable 38 km firing range . As with other Japanese ships being refit, the American-made Harpoon missiles (such as in the initial configuration of the Kongō class) have been replaced with the Japanese-made Type 90 (SSM-1B) surface-to-surface guided missiles.

Japan has also purchased a manufacturing license for these weapons for use on their Kongo class Aegis destroyers. Japan Steel Works will manufacture, assemble and test the weapons.

The fire-control system for the Atago is Aegis Weapon System Baseline 7 phase 1, which will combine American- and Japanese-manufactured systems to make up the complete Aegis system. The Aegis Weapon System baseline 7 has improved tracking accuracy for vertical targets, and an acquisition capability for small low-altitude targets compared with the Aegis Weapon System baseline 4 and 5, used in Kongō class. The Atago also use a new stealthier plain-structure mast, which was originally designed in Japan, rather than familiar lattice type mast. New modified smokestack and other improvements are also introduced to make Atago stealthier.

Like the Kongō class, the Atago destroyers are equipped with a comprehensive suite of weapon systems including:

• Japan Type 90 (SSM-1B) anti-ship missile
• 96-cell Mk-41 VLS (64 cells in the forward area, 32 cells in the stern area)
  • RIM-66 Standard surface-to-air missile
  • RUM-139 VL ASROC
• Two Mark 15 20 mm CIWS gun mounts
• Two torpedo mounts in a triple-tube configuration
• One Mk 45 Mod 4 127 mm 62-caliber gun, in a stealth-shaped mount. Made by Japan Steel Works under an American license from its original manufacturer.

In keeping with Japan's post-war pacifist constitution, the Atago class does not currently carry the Tomahawk missile (although, in theory at least, use of an anti-ship version is permissible). While the two ships of Atago class are entering service, the Tachikaze class destroyers, Tachikaze and Asakaze are to be decommissioned.

Ships in the class

Building No.	Pennant No.	Name	Laid down	Launched	Commissioned	Home port
2317	DDG-177	Atago	5 April 2004	24 August 2005	15 March 2007	Maizuru
2318	DDG-178	Ashigara	6 April 2005	30 August 2006	13 March 2008	Sasebo

External links

• GlobalSecurity.org; JMSDF DDG Atago Class