Hello everyone.
Today we will be examining the Mogami class frigates of the Japanese Navy, officially
the Japanese Maritime Self-Defence Force, or JMSDF for short.
The Mogami is the latest iteration of their stealth frigates, and Japan plans to build
many, many ships of this class.
Now, there is a lot of hype in the Western defence media about the Mogami class.
There are plenty of videos on YouTube that are full of praise for the Mogami, basically
overstating their capabilities, without critical commentary of the limitations of this class.
My personal view on the Mogami class is more nuanced.
I do think that they are very capable, but only for the specific missions that they are
designed to do.
The Mogami class is not a multi-purpose warship.
They are actually built for very specific duties, for example anti-submarine patrols
and mine warfare.
For reasons I will explain in this video, the Mogami class does not have the sufficient
air warfare capabilities to undertake fleet air defence, at least not by themselves.
The Mogami class is built by the Mitsubishi Heavy Industries for the most part, although
a couple of units are also built by the Tamano Shipyard corporation.
Japan wants to build a total of 22 ships, so they are really aiming to mass produce
these frigates, and I think Japan can probably do this.
The production costs are fairly affordable.
The range of figures I’ve seen suggests between 400 million dollars to 450 million
dollars per unit.
Five ships of the class have been launched for the Japanese Navy, with two commissioned.
Japan is also selling 8 ships to Indonesia, with 4 of these to be built in Indonesia.
A key hint we have of the role of the class are the ships they are intended to replace.
The Mogami is replacing the Asagiri class of first generation JMSDF destroyers, and
the Abukuma class of destroyer escorts.
Both of these are old warships.
Neither of these classes can be considered “frontline combatants".
They are rear area patrol ships and anti-submarine escorts.
The Abukuma, the so-called destroyer escort, is small, has no surface-to-air missiles,
no towed sonars, and only basic radars.
It is not a real warship, but rather a patrol ship.
The Asagiri destroyer is slightly better and more survivable, with short-range Sea Sparrow
missiles, but again only truly suitable for patrol duties.
The Mogami class, as their successor, will basically do the same type of missions, except
better.
The Mogami class displaces 5,500 tons at full load, which is large for a frigate.
It has a length of 133 metres and a beam of 16.3 metres.
It has a very small crew of about 90, which supposedly reflects a high level of automation
in the ship’s combat information centre.
The Mogami carries a pair of small rigid inflatable boats, for the purposes of rescue, patrols,
and small unit landings.
Propulsion is combined diesel and gas, also known as CODAG.
For low-speed cruising, the ship relies on its two German MAN diesel engines.
When the ship needs to reach high speed, it switches on a single Rolls-Royce MT30 gas
turbine for additional horsepower.
Maximum speed is somewhere north of 30 knots.
The Mogami class has what appears to be very strong stealth capability, especially compared
to its predecessors, the old anti-submarine destroyers and destroyer escorts.
The Mogami has all the basic stealth requirements, including sloped angular surfaces for the
ship’s belt, and a compact superstructure.
It also has a very clean-looking integrated mast, which is perhaps the defining feature
for a modern stealth warship.
Modern warships operate many, many antennae, to allow the functioning of radars and communication
devices.
These antennae have to be situated high on top of a mast, which makes them easily detectable
to enemy radar.
The integrated mast shields the various antennae from detection, while also minimising the
mutual interference between different electronic systems.
The cylindrical radome at the very top of the mast is reportedly constructed out of
material that simultaneously allows for a low radar cross section, and also high radio
wave transmittance.
This radome contains very important electronics, for example the communication device between
the ship and its helicopter, its passive radar system, the electronic support measures, and
its friend and foe identification system.
According to the Japanese, the structure of the radome also makes it very easy to swap
out damaged electronic systems for new replacements.
So, what missions are the Mogami class designed for?
The answer is anti-submarine warfare, for the most part.
The ship fulfils the role of anti-submarine escort duties for more vulnerable supply ships
and troop transports, and to patrol the rear area.
We can see this, because the Mogami class is very well equipped with different sonars.
It has the latest iteration of domestic Japanese towed array sonar, and a variable depth sonar.
Both are developed by the NEC corporation, a Japanese technology and electrical engineering
firm.
They should enhance both the passive and active sonar capability of the Mogami class, especially
compared to the previous Abukuma class destroyer escort, which only has an antiquated bow sonar.
The Mogami class also has a special hull-mounted Hitachi OQQ-11 mine-hunting sonar.
This suggests that the Mogami class may be able to find and remove naval mines.
The Mogami has a special unmanned surface vehicle with mine-sweeping capabilities, which
is stored towards the rear of the ship, and can be launched through the rear ramp.
Once the Mogami class detects a submarine, it can engage the threat with its Type 12
lightweight ASW torpedo.
The Type 12 torpedo is a fairly new weapon, and the JMSDF has been fairly tight-lipped
about it.
But reportedly, it is optimised for shallow coastal waters.
The Mogami should also have anti-submarine missiles to engage underwater threats at a
much longer range than torpedoes – this weapon is most likely the Type 07 ASROC.
Of course, the Mogami also has facilities to support one SH-60L Seahawk anti-submarine
helicopter.
This Japanese version of the Seahawk is produced by Mitsubishi under license from its US manufacturer.
The SH-60 can carry a large number of sonobuoys, as well as its own Type 12 torpedoes for use
against submarines.
So, the main use of the Mogami class is basically a general patrol ship and anti-submarine escort.
In a combat deployment, its primary purpose is to tow its passive sonar cables, to listen
for enemy submarines.
It has very capable active sonar to back this up if needed.
The Mogami class also likely has a secondary role as a mine detector, and possibly a general
mine warfare ship, depending on the available equipment.
It supposedly has the equipment to lay naval mines of its own.
So long as the Mogami class frigates stick to anti-submarine missions, and mine warfare,
they are likely to perform very well.
Let’s talk about what the Mogami is not designed for.
They are not proper air defence warships.
They will install a Mark-41 vertical launching system of 16 cells, and these are expected
to be fitted with domestic medium-range SAMs, which are the navalised version of the ground-based
Type 03.
The Mogami frigates do not have their vertical launching system just yet, but the necessary
funding has been provided, and the system should be installed soon.
With only 16 VLS cells, the Mogami class will be too lightly armed for proper air defence
duties, keeping in mind that some of these cells will have to carry anti-submarine missiles,
rather than SAMs.
The ship basically won’t have enough ammunition for fleet air defence duties.
An even greater impediment to its air warfare capabilities is that the Mogami does not have
the proper radar suite for long-range air search.
The ship has a very capable OPY-2 AESA radar, but this only in the X-band.
Generally, the X bandwidth has very good resolution at shorter ranges, and is therefore effective
at tracking targets flying close to the sea surface.
It is highly resistant to various background clutter found in low altitudes, especially
near the coast.
For this reason, the X-band is universally favoured for naval fire control radars.
However, the X-band performs poorly at medium to long ranges, and is quite vulnerable at
long ranges to the stealth technology of fifth generation fighters.
Basically, the X-band performs well as a fire control radar, but bad at volume search.
Traditionally, air defence destroyers rely on S-band radars to perform volume search
at long ranges, to detect hostile aircraft, which may have stealth technology.
The S-bandwidth travels much further through the atmosphere than the X-bandwidth.
But the Mogami class does not have that.
This means the class, on its own, is impotent for engaging modern fighters or even bombers,
which typically involves a long engagement range.
That said, the X-band radars on the Mogami should be very suitable for the interception
of incoming cruise missiles, which generally involves a very short engagement range, and
this is something the X-bandwidth excels at.
But even in that case, the low amount of ammunition carried, in terms of SAMs, will make the Mogami
vulnerable to a saturation strike.
Perhaps the only suitable role the Mogami can play, in terms of air defence, is to support
the far more capable Japanese AEGIS destroyers, like the Kongo class for example.
The Mogami can take advantage of the cooperative engagement capability of the AEGIS destroyers,
essentially using their S-band radars to find air targets at long ranges.
On their own, however, the Mogami’s air defence capability is quite lacking, because
of two reasons: number one is the low number of SAMs, or ammunition, because it only has
16 VLS; number two is the lack of a proper volume search radar necessary for finding
stealth aircrafts.
The Mogami class has reasonable anti-surface firepower, with 8 of the Type 17 anti-ship
missiles, distributed in a pair of quad launchers.
The Type 17 is high subsonic, with good sea-skimming qualities, and reportedly high anti-jamming
capabilities.
The current iteration of the naval version has a range of 400 km.
The Mogami class also has a single 5-inch, or 127 mm naval gun, the Mark 45.
This will be useful for defending against small vessels or fighting in the littoral
environment.
So, this concludes my opinion on the Mogami class, the latest iteration of frigates Japan
plans to mass produce.
In terms of production numbers, it would be their version of the Type 054A, but as we
have discussed, their capabilities and mission set do not resemble the Type 054A.
The Mogami class is designed for anti-submarine patrols and escort duties, and perhaps mine
warfare as their secondary function.
They are essentially rear area warships, rather than frontline units.
The Mogami is ill-suited for fleet air defence.
This is because of low ammunition, in terms of SAMs, and also because it lacks a volume
search radar, which impedes its engagement of stealth aircrafts at range.