TOKYO --- Rumors that the Japan Maritime Self-Defense Force's third "aircraft carrying destroyer" would mark a major improvement in size and capability over the Hyuga class ships now entering service have been confirmed.
The new 22DDH will be 248 meters long and 39 meters in beam, and displace more than 24,000 tons. This makes her almost 50 percent larger than the Hyuga class and places an unbearable semantic strain on the use of the term "destroyer" to describe these ships. To put the size of the ship into context, she is comparable with a World War II Essex-class fleet carrier.
Illustrations of the 22DDH show her to be a full-fledged helicopter carrier with no real destroyer characteristics. The superstructure is very similar to that of the Hyuga class with the difference that the 01 deck is extended forward, probably to accommodate a vertical launch silo for air defense missiles. The point defenses of the new ships are more than doubled, with three Phalanx Mk 15 mountings and two RAM launchers replacing the pair of Phalanx mounts on the older ship. Significantly, while one of the Phalanx mounts on the Hyuga is situated forward on the flight deck, and thus obstructs fixed-wing operations, the 22DDH has all of its mounts located on sponsons clear of the flight deck itself.
The flight deck layout on the 22DDH differs significantly from that of the Hyuga class. One of the lifts has been moved from the centerline to the deck-edge position. The added width of the flight deck has been used to shift the axis of air operations clear of the remaining centerline elevator. The number of munitions elevators feeding the flight deck has been increased from two to four.
A vertical launch silo built into the rear of the flight deck on the Hyuga has been removed, once again reducing obstructions to flight operations. Flight deck operations capacity has been increased from two to seven helicopters.
Japanese accounts suggest that one of the reasons for the drastic increase in size of the 22DDH design is a planned shift to the V-22 Osprey as the primary air group element for these ships. It is not clear whether these would be replacements for or supplemental to the SH-60Ks that equip the Hyuga class. These accounts also make it clear that the F-35B short takeoff and vertical landing variant of the Joint Strike Fighter is seen as a key system for these ships. Apparently, provision for the operation of UAVs is being included within the design.