Atago-class destroyer

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
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.