On March 22nd Japan put into service a second 27,000 ton “destroyer” (the Kaga, DDH 184) that looks exactly like an aircraft carrier. Actually it looks like an LPH (Landing Platform Helicopter) an amphibious ship type that first appeared in the 1950s. This was noted when Izumo, the first Japanese LPH was launched in 2012 (it entered service in 2015). The Izumos can carry up to 28 aircraft and are armed only with two 20mm Phalanx anti-missile cannon and launcher with sixteen ESSM missiles for anti-missile defense.
LPHs had no (or relatively few) landing craft but did carry a thousand or more troops who were moved ashore using the dozen or more helicopters carried. The first American LPH (the USS Iwo Jima) was an 18,400 ton ship that entered service in 1961, and carried 2,000 troops and twenty-five helicopters. Until Izumo showed up, several nations operated LPHs, and Britain and South Korea still do. The U.S. retired its last LPHs in the 1990s, but still have a dozen similar ships that include landing craft (and a well deck in the rear to float them out of) as well as helicopters. A few other nations have small carriers that mostly operate helicopters but carry few, if any troops.
The Izumos are the largest LPHs to ever to enter service. It differs from previous LPHs in not having accommodations for lots of troops and having more powerful engines (capable of destroyer-like speeds of over fifty-four kilometers an hour). Izumo does have considerable cargo capacity, which is intended for moving disaster relief supplies quickly to where they are needed. Apparently some of these cargo spaces can be converted to berthing spaces for troops, disaster relief personnel, or people rescued from disasters. There are also more medical facilities than one would expect for a ship of this size. More worrisome (to the Chinese) is the fact that the Izumo could carry and operate the vertical take-off F-35B stealth fighter, although Japan has made no mention of buying that aircraft or modifying the LPH flight decks to handle the very high temperatures generated by the F-35B when taking off or landing vertically. The Chinese are also upset with the name of this new destroyer. Izumo was the name of a Japanese cruiser that was a third the size of the new “destroyer” and led the naval portion of a 1937 operation against Shanghai that left over two-hundred-thousand Chinese dead. The Chinese remember all this, especially the war with Japan that began unofficially in 1931 and officially in 1937.
The Izumo is part of a trend. In 2009, Japan launched its second Hyuga class “LPH”. Earlier in 2009, it commissioned the first of these "helicopter-carrying destroyera". This was the first Japanese aircraft to enter service since 1945. The Hyuga class are 197 meter (610 foot) long, 18,000 ton warships that operates up to eleven (mostly SH-60) helicopters from a full length flight deck. Although called a destroyer, it very much looks like an aircraft carrier. While its primary function is anti-submarine warfare, the Hyuga will also give Japan its first real power projection capability since 1945. The Hyuga was also the largest warship built in Japan since World War II. The Japanese post World War II constitution forbids it from having aircraft carriers, which is the main reason it is called a destroyer. That, and the desire to not make the neighbors anxious. East Asian nations still have bad memories about the last time Japan had lots of aircraft carriers. Meanwhile, more Japanese are calling for the constitution to be changed, not just so these odd looking destroyers can be more accurately named but because it would then be easier to develop nuclear weapons if China became more threatening. A constitutional change would also help the economy by making it possible to export weapons and that is one reason why it is happening.
The Hyuga, but not the Izumos, have major weapons on board. The Hyuga’s have sixteen Mk41 VLS (Vertical Launch System) cells for anti-aircraft and anti-ship missiles. There are also two 20mm Phalanx anti-missile cannon and launcher with sixteen ESSM missiles for anti-missile defense. There are also two triple 324mm (12.75 inch) torpedo mounts for anti-submarine work. There is a crew of three hundred and seventy and a top speed of about sixty kilometers an hour. A third Hyuga class ship was planned but this was cancelled when it was decided to proceed with the larger Izumo class DDHs. The Izumo class is similar (but slightly larger) than the Hyugas. The Izumo has an elevator (to the hanger deck under the flight deck) powerful enough to carry an F-35B fighter or MV-22 tilt-wing transport.
The last Japanese warship to be called the Hyuga was a World War II battleship that entered service in 1918, and was converted to a hybrid battleship/aircraft carrier in 1943. The new Hyuga was intended for peacekeeping missions as well, and for that role its many helicopters will be most useful. During World War II there was also a Japanese battleships named Ise, which was the lead ship of a class of ships that also contained the Hyuga. Both were 35,000 ton warships, and both were sunk, in the same week, in late July 1945. The Ise had been rebuilt during the war as an aircraft carrier (actually a hybrid battleship/aircraft carrier).