The Hyūga-class is one of the most important assets of the Japan Maritime Self-Defense
Force, shortly JMSDF. At first glance, many may say, two helicopter destroyers of this
class have similar design logic with their big sisters, the Izumo-class. But, they are
different. As the Weapon Detective, we are investigating the Hyūga-class, the half-century
dream of Japan. Please don't forget to subscribe to our channel,
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our channel. Due to its appearance, the classification
of helicopter destroyer for the Hyūga-class naturally causes a rightful debate. These
two surface combatants look like aircraft carriers rather than conventional warships.
But if we look at the details, we may reach a different conclusion. To better understand
the Hyūga-class, let's look at its historical background and features. A half-century dream
for Japan is one of the most accurate definitions for the Hyūga-class. As we mentioned in our
Izumo-class video, this dream goes back to even the late 1940s.
Japan was demilitarized after the Second World War.
But due to quickly rising tension between the communist and free worlds, the US-led
Western allies began to need a stronghold in the Pacific.
So, they permitted Japan to establish the Maritime Safety Agency in 1948. It was just
the first step for rebuilding up a navy. In 1952, Tokyo intended to acquire an escort
aircraft carrier for the anti-submarine warfare mission for this paramilitary force. Washington
was also favourable about this plan. Two years later, Japan established the Self-Defense
Forces. The naval part of this force, the JMSDF, took
over the aircraft carrier procurement plan from the Japanese Maritime Safety Agency.
While the negotiation continued for an Essex-class ship's transfer, Japan changed its mind in
1959. In the same year, the dream, which led to
the Hyūga-class, began. Tokyo now decided to build an indigenous ship.
It would be a helicopter carrier, carry 18 Sea Kings, and operate three helicopters simultaneously.
This vessel would have no fixed-wing aircraft and command the escort fleet.
As you see, its design philosophy was highly similar to Hyūga-class.
But, the JMSDF would have to wait to realize this dream.
The helicopters of the time were not as effective for anti-submarine warfare missions as today.
Also, the ship would have a high cost. So, Tokyo terminated the programme and decided
to build lots of cost-effective conventional destroyers.
In 1967, Tokyo initiated the Third Defense Build-up Plan. According to this plan, the
JMSDF needed escort fleets, which consisted of eight surface combatants and six to eight
anti-submarine warfare helicopters, to deal with the threat of the new Soviet nuclear
submarines. Initially, Japan intended to build the 8,300-ton helicopter destroyers, which
would carry six helicopters. But due to budget problems, Tokyo decided
to commission two Haruna-class and two Shirane-class destroyers instead.
These vessels could accommodate three Sea Kings.
We may also mention the Japanese intention to build an aircraft carrier with the Harrier
jump-jets against the Soviet bombers with long-range anti-ship missiles in the 1970s.
In the 1980s, this plan was abandoned, but it led to the construction of the Izumo-class
later. A new hope arose in 1998 when Japan began
a study for the successor of the Haruna-class. After this study, in 2000, the JMSDF decided
that it was now time to build an actual helicopter carrier. As the child of this decision, the
first ship, JS Hyūga, was ordered in 2004. She was laid down in 2006 and launched in
2007. After a half-century from the original plan,
the JMSDF commissioned its first helicopter carrier in 2009.
The second ship, JS Ise, was ordered in 2006 and commissioned in 2011.
The Hyūga-class ships are primarily anti-submarine warfare carriers. But, they can also serve
as flagships of the escort fleets and support amphibious and humanitarian operations.
The hull and superstructure of the Hyūga-class have a design to reduce the radar cross-section.
When they are inside, the motorboats placed in the hull are covered by low radar cross-section
cover to ensure stealth. Still, we should accept that the surface of
the Hyūga-class is not smooth for a stealth ship.
The island type superstructure is at the starboard side. It has a length of 70 meters and a width
of 9 meters. The bridge is on the 4th floor.
The air traffic control room is at the rear and on the same level as the bridge.
The ship's joint operations centre and combat information centre is on the second floor
of the island. The medical room of the Hyūga-class includes
eight beds and an intensive care unit. The 19,000-ton Hyūga-class has the same propulsion
system with four 25,000 horsepower IHI/GE LM2500-30 gas turbines as the 9,500-ton Kongō-class
destroyer. But thanks to the well-designed hull of the Hyūga-class, it has the same
maximum speed as the Kongōs. According to the JMSDF official website, the
complement of the Hyūga-class is about 380-person. The ship has a length of 197 metres, a beam
of 33 metres, and a draught of 7 metres. Its standard weight is 13,950 tons, while its
fully-loaded displacement is 19,000 tons. The combined gas and gas configuration propulsion
system consists of four 25,000 horsepower IHI/GE LM2500-30 gas turbines. The maximum
speed of the Hyūga-class is 30 knots. The ship has one 16-cell Mk 41 vertical launching
system for the RIM-162 ESSM air defence and RUM-139 VL ASROC anti-submarine warfare missiles.
There are also two Mk 15 Phalanx close-in weapon systems, two 324mm triple torpedo tubes,
and seven 12.7mm machine guns on the Hyūga-class. The ship's OYQ-10 advanced combat direction
system, supported by artificial intelligence technology, can discriminate the possible
threats and determine the most suitable weapon system for the weapon officer to deal with
them. The FCS-3 has four phased array antennas.
It uses the C-band for search and the X-band for ESSM weapon control. The FCS-3 can simultaneously
detect about 300 targets at a range of 200 kilometres.
The range of the OPS-20C surface search radar is 46.3 kilometres.
The ship also has the OQQ-21 sonar system, which delivers high accuracy in detection
distance and shallow water. Thanks to this sonar, the Hyūga-class can attack the enemy
submarines with the Type 97 lightweight torpedoes and VL ASROC missiles. The OQQ-21 also help
to detect a possible torpedo attack and launch countermeasures.
The RUM-139 VL ASROC is basically an inertial navigation system-guided missile, which carries
a Mk 46 Mod 5A lightweight torpedo. Its range of 22 kilometres.
The Mk 46 Mod 5A has an active or passive/active acoustic homing guidance system and a range
of 11,000 metres. The torpedo can be effective at a depth of 370 metres.
Japan plans to replace the VL ASROCs with domestically developed Type 07 missiles. This
missile has 8 kilometres longer range. The Hyūga-class can launch the Type 97 lightweight
torpedoes from its triple torpedo tubes. The RIM-162 ESSM air defence missile has a
range of 50 kilometres and a maximum speed of Mach 4.
The rate of fire for the 20mm six-barrel Mk 15 Phalanx close-in weapon system is 4,500
rounds per minute. Its effective range is only about 1,500 metres. The effectiveness
of the Phalanx against the latest Chinese anti-ship missiles, such as YJ-12 with a maximum
speed of Mach 4, is questionable. Instead of its armament, the primary weapon
system of the Hyūga-class is its helicopters. In general, the ships of this class carry
three SH-60K anti-submarine warfare and one MCH-101 mine countermeasures and transport
helicopter. But, they can carry up to 11 helicopters. For a conventional surface combatant with
an aft helipad, the time between landing a helicopter and taking off another is generally
20 minutes. But, thanks to its aircraft carrier-like design,
the Hyūga-class allows simultaneously operating three helicopters. So, the ship gives a tremendous
combat capability enhancement to the JMSDF comparing the previous Haruna-class.
The Hangar is 120 metres long and 19-20 metres wide. But, only a 60-metre part is suitable
to park, the rest is generally used to carry supplies and vehicles. This part also includes
the maintenance section. Two big elevators connect the hangar from
the flight deck. The front elevator is 20 metres long and 10 metres wide, while the
rear elevator is 20 metres long and 13 metres wide.
The Hyūga-class has two small elevators to transfer crew and light cargos such as ammunition.
The small elevator at the front is also used for moving the sick or injured person to the
medical bay. In several exercises and operations, the Hyūga-class
has operated AH-64D Apache, CH-47JA Chinook, and UH-60J helicopters.
So, it can support an amphibious operation by transferring the combat troops to shore
and providing air support to them. Also, the ship has good capability for humanitarian
missions, such as disaster relief and search and rescue.
Also, in 2013, the US Marine Corps deployed its V-22 Ospreys on JS Hyūga during joint
amphibious exercises. Three years later, this ship operated the
US MV-22 Ospreys for the relief efforts following the Kumamoto earthquake.
As a non-combatant country, Japan has generally deployed the Hyūga-class ships in naval exercises,
humanitarian operations, and goodwill missions. But occasionally, the JMSDF also used these
vessels for more intense duties. On February 10, 2012, JS Hyūga spotted and
monitored four Chinese Navy frigates, which sailed about 110 kilometres northeast of Miyakojima.
In June 2017, alongside Atago-class destroyer JS Ashigara, JS Hyūga joined the US Navy's
Carrier Strike Group 1 and Carrier Strike Group 5 to respond to tensions caused by the
North Korean nuclear weapons programme. The JMSDF's classification of the Hyūga-class
as destroyers has caused some criticism. Of course, these vessels are nothing like a destroyer
in terms of size and design. They look like a light aircraft carrier. But different from
the Izumo-class, the Hyūga-class has a mission definition close to a destroyer. Thanks to
their onboard systems, these ships have a similar combat capability to current multi-mission
frigates. So without using their helicopters, they can conduct conventional naval operations
other than anti-surface warfare. Yet, JS Izumo and JS Kaga have only close-range
defensive weapons. They can only rely on their helicopters for many types of missions.
As mentioned in our Izumo-class video, JS Izumo and JS Kaga are not helicopter destroyers
but future aircraft carriers. Japan is now reinforcing these vessels' decks for the F-35B.
But, there is no known plan for similar work for JS Hyūga and JS Ise.
The Japanese industry needs raw materials, which come from over the seas. So in a possible
war, Japan would also need effective escort fleets to keep open the sealines while the
main fleet would fight. During the last 20 years, amphibious assault
ships, which can also serve as light aircraft carriers, have become a new trend for many
navies. Thanks to their flexible design, these multi-purpose vessels can perform many types
of missions in wartime. In peacetime, the amphibious assault ships execute important
tasks for humanitarian missions. We can say that the Hyūga-class so-called
helicopter destroyers are the Japanese style of this new trend. In wartime, they can perform
different types of combat missions, such as anti-submarine warfare, escort, and amphibious
assault. JS Hyūga and JS Ise have also proved themselves for humanitarian missions in peacetime.
Our analysis is that the classification of the Hyūga-class is in a unique place between
amphibious assault ships and destroyers, not a semi-aircraft carrier.
Thanks for watching our video. And please don't forget to subscribe to our channel and
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