Japan 20000t SPY-7 guided missile destroyer/cruiser

[Ainen]

And kinda pointless. I'd give it a couple of 76mm instead.

Bigger surface ships tried going couple 76mm route in the 1960s...didn't end well.

(1)It isn't like a larger gun, built on a similar tech level, is less capable in just about anything other than the CIWS role; guns of any size are automatable, and we know since 1970s1940s they work perfectly fine.

(2)For the capability, the opposite is obviously the case, as a larger shell simply makes more room for any usable content, flies order(s) of magnitude further and faster. Nor it's probably that much more expensive to produce, as the difference is mostly steelwork and actuators of heavier turret, the 'smart' part is similar. Smaller naval guns aren't that cheap just because they're small.
Nor their smart ammo is cheap because it's small. It's just less capable, and far more difficult to be made capable. Zumwalt 155 guns and their ammo shall serve as a stern warning here.

(3)The positive difference, if it exists, is limited to smaller guns already being available (but we're already developing a whole new unique, large ship?), and being easier to mount...which is worth the less the larger the ship. Installing it in the primary DP position is just a waste.

(4)It made a lot of sense when there were just no big enough ships to go beyond a normal DP weapon; missiles just don't depend on launcher size, unless they physically can move with them. Nor their usable magazine scale well with the size of a ship (it scales linearly=badly).

(5)But for large ships, gun as a system always benefited disproportionally from size. You just waste the already obtained internal volume, structural rigidity otherwise. Disproportionally larger shells(of any purpose), disproportionally more ammo, disproportionally cheaper.
This isn't about an established separate need - more about not using the opportunity to install a balanced(to size) weapon, which is already here.

 

[Maro.Kyo]

Bigger surface ships tried going couple 76mm route in the 1960s...didn't end well.

(1)It isn't like a larger gun, built on a similar tech level, is less capable in just about anything other than the CIWS role; guns of any size are automatable, and we know since 1970s1940s they work perfectly fine.

(2)For the capability, the opposite is obviously the case, as a larger shell simply makes more room for any usable content, flies order(s) of magnitude further and faster. Nor it's probably that much more expensive to produce, as the difference is mostly steelwork and actuators of heavier turret, the 'smart' part is similar. Smaller naval guns aren't that cheap just because they're small.
Nor their smart ammo is cheap because it's small. It's just less capable, and far more difficult to be made capable. Zumwalt 155 guns and their ammo shall serve as a stern warning here.

(3)The positive difference, if it exists, is limited to smaller guns already being available (but we're already developing a whole new unique, large ship?), and being easier to mount...which is worth the less the larger the ship. Installing it in the primary DP position is just a waste.

(4)It made a lot of sense when there were just no big enough ships to go beyond a normal DP weapon; missiles just don't depend on launcher size, unless they physically can move with them. Nor their usable magazine scale well with the size of a ship (it scales linearly=badly).

(5)But for large ships, gun as a system always benefited disproportionally from size. You just waste the already obtained internal volume, structural rigidity otherwise. Disproportionally larger shells(of any purpose), disproportionally more ammo, disproportionally cheaper.
This isn't about an established separate need - more about not using the opportunity to install a balanced(to size) weapon, which is already here.

Before all this, you've got to consider that this ship is something that is replacing Aegis Ashore and is meant for the defence of mainland Japan. One of its key benefits is envisioned to be freeing other JMSDF Aegis ships of Fleet Escort Force from BMD role so that they could actually be deployed alongside other Fleet Escort Force Ship to ECS without causing a BMD gap. As such, the possibility of ship main gun of ASEV actually being employed in combat is very low in the first place and as TomS has pointed out, bigger guns are "pointless" for this ship's role.

 

[TomS]

Just so. A couple of small guns would be more useful on dealing with small boats (which China does use, though not to the same extent as Iran). The 5-inch gun is rather ill-suited to dealing with small surface threats and IMO serves very little purpose on major combatants in general.

 

[Cordy]

ASEV：
Length： ～190m （Maya Class： ～170m）
Beam： ～25m （Maya Class： ～21m）
Standard displacement：～12000t （Maya Class： 8200t）
Crew：240 （Maya Class： ～300）

MK-41 VLS: 128 cells (Maya Class： 96 cells）

Does the Standard displacement figure of ~12,000 mt look understated (Standard displacement also known as Washington displacement in which ship is fully loaded including armament only excluding fuel).
The Zumwalt has very similar dimensions (Length 186m; Beam 24.7m) with a quoted fully loaded displacement of 15,995 mt, assuming the ASEV fuel load of approx 1,000 mt that would give fully loaded displacement of only 13,000 mt, a 3,000 mt difference?

 

[raptor82]

Does the Standard displacement figure of ~12,000 mt look understated (Standard displacement also known as Washington displacement in which ship is fully loaded including armament only excluding fuel).
The Zumwalt has very similar dimensions (Length 186m; Beam 24.7m) with a quoted fully loaded displacement of 15,995 mt, assuming the ASEV fuel load of approx 1,000 mt that would give fully loaded displacement of only 13,000 mt, a 3,000 mt difference?

“（the displacement of the ASEV）is 1.7 times that of the Flight III”

“DDG-51 Flight III : standard displacement :~7000t,（ Full loaded ）displacement: 9650t ”

 

[Cordy]

“（the displacement of the ASEV）is 1.7 times that of the Flight III”

“DDG-51 Flight III : standard displacement :~7000t,（ Full loaded ）displacement: 9650t ”

Thanks for your info “the displacement of the ASEV is 1.7 times that of the Flight III” looks much more realistic, which if taking CBO FLD figure for Flt III of 9870 mt would give ASEV FLD of ~17,000 mt, slightly higher than the Zumwalt's 16,000 mt

The CBO quote the DDG-51 Flt III light displacement as 7700 mt, defined as the weight of the ship excluding munitions, fuel, water, ballast, stores, crew etc. so puzzled and makes no sense as to why the Japanese can quote a standard displacement of only ~7000 mt.

 

[Forest Green]

Japan's Missile Defense Ships Will Now Be Multi-Role, Cruiser-Like

Japan moves away from procuring dedicated missile defense ships, opting for a multi-role, cruiser-like design that focuses on that mission.

www.thedrive.com

 

[barrett]

Japan MoD Secures $2.5 Billion To Build Two ASEV For FY2024

Japan MoD Secures $2.5 billion to build two ASEV for FY2024 - Naval News

The Japanese MoD announced it has secured $2.5 billion for fiscal year 2024 to build two Aegis System Equipped Vessels (ASEV) for the JMSDF.

www.navalnews.com

イージス・システム搭載艦建造３７３１億円で決着　２４年度予算案（毎日新聞）｜ｄメニューニュース

　防衛省は１９日、２０２４年度当初予算案で、イージス・システム搭載艦の建造費用として、ほぼ概算要求通…

topics.smt.docomo.ne.jp

The Japanese Ministry of Defense (MoD) on December 19 announced it has secured $2.59 billion (373.1 billion yen) for fiscal year 2024 from the Ministry of Finance to build two Aegis System Equipped Vessels (ASEV), which are alternatives to Japan’s now-scrapped plan for a land-based Aegis Ashore ballistic missile defense system.

 

[sferrin]

Japan MoD Secures $2.5 Billion To Build Two ASEV For FY2024

Japan MoD Secures $2.5 billion to build two ASEV for FY2024 - Naval News

The Japanese MoD announced it has secured $2.5 billion for fiscal year 2024 to build two Aegis System Equipped Vessels (ASEV) for the JMSDF.

www.navalnews.com

イージス・システム搭載艦建造３７３１億円で決着　２４年度予算案（毎日新聞）｜ｄメニューニュース

　防衛省は１９日、２０２４年度当初予算案で、イージス・システム搭載艦の建造費用として、ほぼ概算要求通…

topics.smt.docomo.ne.jp

The Japanese Ministry of Defense (MoD) on December 19 announced it has secured $2.59 billion (373.1 billion yen) for fiscal year 2024 from the Ministry of Finance to build two Aegis System Equipped Vessels (ASEV), which are alternatives to Japan’s now-scrapped plan for a land-based Aegis Ashore ballistic missile defense system.

Why did they scrap Aegis Ashore?

 

[Josh_TN]

Why did they scrap Aegis Ashore?

There were huge pragmatic concerns with where it could be adequately located with sufficient clearance downrange for boosters and misfires, and also radar horizon/detection without interfering with local air traffic and other civilian infrastructure. I do not think any officials came out and stated it, but I imagine there were also concerns with the vulnerability of a static site to any type of attack, ballistic or otherwise.

Note that the defenses to be installed on Guam have all of the same concerns, and I suspect US will struggle to site all of the radars it wants due to local emissions concerns. Aegis ashore was rejected there purely for vulnerability reasons, and as such the radars and launchers are all to be trailer mounted.

ETA:

The US defensive plan for Guam likely also is largely static sites despite nominally be relocatable equipment. I think the main advantage of using ICBS, SPY-7, and Mk41 trailers (among other systems) vice Aegis Ashore is that at least the combat system, all four radar faces, and the magazine aren't colocated where one hit destroys every single piece of capability.

 

[Cordy]

Japan MoD Secures $2.5 Billion To Build Two ASEV For FY2024

Japan MoD Secures $2.5 billion to build two ASEV for FY2024 - Naval News

The Japanese MoD announced it has secured $2.5 billion for fiscal year 2024 to build two Aegis System Equipped Vessels (ASEV) for the JMSDF.

www.navalnews.com

イージス・システム搭載艦建造３７３１億円で決着　２４年度予算案（毎日新聞）｜ｄメニューニュース

　防衛省は１９日、２０２４年度当初予算案で、イージス・システム搭載艦の建造費用として、ほぼ概算要求通…

topics.smt.docomo.ne.jp

The Japanese Ministry of Defense (MoD) on December 19 announced it has secured $2.59 billion (373.1 billion yen) for fiscal year 2024 from the Mini

The DoD FY2024 (March 2023) Justification Book Navy SCN quotes cost of two Burke Flight IIIs as $4.43 billion, 70% more expensive than the Japanese ASEVs, the big unknown is if the build up of the figures comparable, at first glance makes the smaller Burkes look very expensive.

 

[TomS]

The DoD FY2024 (March 2023) Justification Book Navy SCN quotes cost of two Burke Flight IIIs as $4.43 billion, 70% more expensive than the Japanese ASEVs, the big unknown is if the build up of the figures comparable, at first glance makes the smaller Burkes look very expensive.

Er, check your math. The amount secured for ASEV in the current budget is not the total amount to build two ships. The Naval News story says:

The ministry expects the total construction cost for each [ASEV] vessel to reach about 395 billion yen as of late August.

and

In comparison, the latest U.S. Arleigh Burke-class Aegis destroyer (DDG-51 class), in the case of Flight III, the latest estimate for 2023 is $2 billion (about 290 billion yen) per ship.

That makes ASEV about 35% more expensive than a Flight III DDG-51. Even if we take the $2.95b price fro a Flight III instead, it makes the DDG-51 only 424 billion yen, about 7% more expensive. And that leaves us with the question of what's getting left out of ASEV. My hunch is ASW.

 

[Cordy]

I most say do I not follow your logic, are you seriously suggesting we take Naval News $2 billion figure for the cost of a Burke Flight III and not the DoD FY2024 Justification Book figure of $2.2 billion ($4.43/2).

 

[TomS]

I most say do I not follow your logic, are you seriously suggesting we take Naval News $2 billion figure for the cost of a Burke Flight III and not the DoD FY2024 Justification Book figure of $2.2 billion ($4.43/2).

Like I said, even if we take the DoD value, ASEV is still not 70% less expensive per unit that a Flight III. A 7% differential is very small and is probably reflecctive of the efficiency of Japanese shipyards and the lower DC standards being applied.

If you're looking at cost on a per-ton basis, "steel is cheap, and air is free" comes to mind. But designing a new hull is not.

 

[Kota]

A 7% differential is very small and is probably reflecctive of the efficiency of Japanese shipyards and the lower DC standards being applied.

DC standards? Like damage control? If so I haven't seen anything suggesting Japanese damage control is sub-standard when compared to the US. If anything their preventative measures seem to be quite exceptional seeing as how few failures we see with how large of a fleet Japan operates.

But designing a new hull is not.

The ASEV likely isn't a clean sheet design. Even the Hyuuga and Izumo used existing designs, just enlarged to the required tonnage.

 

[Cordy]

Like I said, even if we take the DoD value, ASEV is still not 70% less expensive per unit that a Flight III. A 7% differential is very small and is probably reflecctive of the efficiency of Japanese shipyards and the lower DC standards being applied.

If you're looking at cost on a per-ton basis, "steel is cheap, and air is free" comes to mind. But designing a new hull is not.

Another write up on ASEV buy USNI saying Japan’s Defense Ministry Tuesday has secured the funding for the build of the two new ASEV Aegis destroyers confirming cost of 373.1 billion yen / $2.6 billion, a slight reduction from the 379.7 billion yen / $2.64 billion, that the Ministry sought in its August FY 2024 budget request.

So it would confirm my earlier post the two FY2024 Burkes budgeted at $4.43 billion are 70% more expensive, the detail breakdown of the US and Japanese budgets are unknown so no exact apples to apples comparison is possible, but would repeat at first glance it makes the smaller Burkes look very expensive in comparison to the Japanese ASEVs.

https://news.usni.org/2023/12/20/japan-locks-in-funding-for-2-new-aegis-destroyer

 

[Hood]

Note the article says the funding is for FY2024 and that two ships are to be built, one from FY2024 and one from FY2025. The $2.6 billion is the first budget request for the long-lead items and initial work on the first hull. The second ship is not fully funded yet as the Japanese Navy won't have put their FY2025 funding request in yet. So its too early yet to determine the final price.

 

[starviking]

There were huge pragmatic concerns with where it could be adequately located with sufficient clearance downrange for boosters and misfires, and also radar horizon/detection without interfering with local air traffic and other civilian infrastructure. I do not think any officials came out and stated it, but I imagine there were also concerns with the vulnerability of a static site to any type of attack, ballistic or otherwise..

I just saw the whole shebang as a civilian in one of the designated basing areas - which was chosen as the SDF actually owned land there.

There was a furore when it was discovered that the SDF had used Google Earth to determine the terrain at the site, using rulers on computer screens, IIRC. We didn’t have the booster or radar concern, given the location, well - save for fishing vessels.

The biggest problem was the locals didn’t see any benefit to the project. Most areas of Japan expect some kind of kickback in exchange for hosting national infrastructure - but nothing was offered, so no support was forthcoming.

 

[Cordy]

Note the article says the funding is for FY2024 and that two ships are to be built, one from FY2024 and one from FY2025. The $2.6 billion is the first budget request for the long-lead items and initial work on the first hull. The second ship is not fully funded yet as the Japanese Navy won't have put their FY2025 funding request in yet. So its too early yet to determine the final price.

In the Naval News Dec 19 write up by their Japanese defense writer Kosuke Takahashi on the ASEV destroyer contract it stated the Japanese Ministry of Defense (MoD) on December 19 announced it has secured $2.59 billion (373.1 billion yen) for fiscal year 2024 from the Ministry of Finance to build two ASEV, which are alternatives to Japan’s now-scrapped plan for a land-based Aegis Ashore ballistic missile defense system.
"In a press release following today’s ministerial-level negotiations, the defense ministry specifically said that 373.1 billion yen as construction costs of the two ASEV was allocated on the two promises:
(1) it will aim to build an effective project management system ;
(2) when acquiring and updating Aegis destroyers in the future, such as updating the Kongo-class Aegis destroyers, it will take a zero-based review regarding the selection of to-be-installed radars (for successors to the Kongo-class ships).
The defense ministry has selected Lockheed Martin AN/SPY-7 solid-state radars (SSRs) on the two ASEV over Raytheon’s AN/SPY-6 radar, which was originally designed for US Navy warships equipped with the Aegis Combat System."

Which interpret as the 373.1 billion yen/$2.59 billion is the fully funded cost of the two ships not just FY2024 funding as is the DOD FY2024 Justification Book figure of $4.43 billion for two Burkes.


https://www.navalnews.com/naval-new...res-2-5-billion-to-build-two-asev-for-fy2024/

 

[apparition13]

Japan has one of the of the top three shipbuilding industries on the planet. The US shipbuilding industry is practically defunct. They are consistently paying much less for similar ships, I think because of this.

As are South Korea, but they don't seem to have separated power plants like Japan and the USN do.

 

[Forest Green]

Radar For Japan's New Missile Defense Ships Passes Critical Space Object Tracking Test

Japan's Aegis Combat System-equipped warships are also getting Tomahawk cruise missiles, which crews have begun training on.

www.twz.com

 

[donnage99]

from lockheed martin

 

[Moose]

from lockheed martin

It's the Mega-Connie.

 

[sferrin]

from lockheed martin

 

[aonestudio]

Rolls Royce MT30 selected to power Japan’s ASEV

Rolls Royce MT30 selected to power Japan’s ASEV

www.rolls-royce.com

 

[raptor82]

ASEV rendering updated：

2024年版防衛白書、海自イージス・システム搭載艦の最新イメージ図を掲載（高橋浩祐） - エキスパート - Yahoo!ニュース

防衛省は7月12日に公表した2024年版防衛白書の中に、海上自衛隊向けに新造するイージス・システム搭載艦の最新のイメージ図を掲載した。艦の形状や主な兵装はこれまでに公開されてきた同艦のイメージ図と同様

news.yahoo.co.jp

 

[Pirate Pete]

Both the MRX (Marine Reactor X) and DRX (Deep-Sea Reactor X, a smaller derived design for use in submersibles and other underwater roles including seabed systems) programs date back to the early 1990s and succeeded the Mutsu reactor program. The first MRX prototype came on line in 1996 with the first DRX reactor going live the following year. The MRX program at the very least was still fully active in the late 2000s; originally the JS Shirase (AGB-5003) was to be a nuclear powered icebreaker using the MRX, but the Ministry of Finance insisted on a change to a much inferior conventional powered design late in the day (there may have been bribes and kickbacks involved there).

And that doesn't even include work done on the q.t. by the MSDF and TRDI into liquid gas cooled and other naval reactor designs during the 1980s and into the early 90's at least.

Incidentally, the Matsu appears to have been not only intended to be a proof of concept/technology demonstrator for domestically built nuclear merchant ships but also (from relatively late on in the program's development) to double as a disguised testbed for a domestic submarine reactor hidden in plain sight, much as its West German counterpart the Otto Hahn was. This meant its reactor was rather underpowered for a large surface vessel. The follow-on design to the Mutsu was in contrast planned to have a more powerful reactor much better suited to naval and commercial surface ships; detailed design work was intended to begin in 1975 with completion (including fuel loading) and service entry by 1983, indicating that the keel would have been laid down in 1980. However the (actually minor, but ultimately politically fatal) shielding problem with the Mutsu reactor (which was traced back to what could only be called pure bureaucratic stupidity) and the resulting popular backlash (helped nicely along by Soviet agents and associated fronts and/or useful idiots it should be noted) would cause that particular plan to be indefinitely shelved, something that Japan would soon increasingly come to regret dearly.

Sincerest apologies for referring so far back in this thread, but…
Are there any details of the follow-on vessel planned after Mutsu?

 

[MihoshiK]

It's the Mega-Connie.

When a Burke and a Connie love each other very much...

 

[Grey Havoc]

Sincerest apologies for referring so far back in this thread, but…
Are there any details of the follow-on vessel planned after Mutsu?

Haven't found anything more unfortunately, but I'll keep an eye out.

 

[barrett]

The Maritime Self-Defence Force's new ‘Aegis system-equipped’ vessels, the first of which will be built by Mitsubishi Heavy Industries and the second by JMU, sign a construction contract.
Contract signed for the construction of Aegis system-equipped vessels

https://www.mod.go.jp/j/press/news/2024/09/18c.html

 

[Cjc]

Good god is it the early 2000s again? These renders are horrible. I've seen better renders of this ship on reddit. Truly modeling (even on computers) is a lost art for companys and governments these days.

 

[Scott Kenny]

Good god is it the early 2000s again? These renders are horrible. I've seen better renders of this ship on reddit. Truly modeling (even on computers) is a lost art for companys and governments these days.

They're still using 2000s software to do their modeling. Can't bother retraining the people we hired "for life" (ie, till 65 or so).

 

[Arjen]

Good god is it the early 2000s again? These renders are horrible. I've seen better renders of this ship on reddit. Truly modeling (even on computers) is a lost art for companys and governments these days.

Have you considered the possibility that the lack of detail is intentional because details are yet to be settled? I will accept more detailed renders can be found of the proposed ships, but the details presented might just be fillers to give a prettier picture.

 

[Archibald]

Maybe the thread title could be changed, since the ships have shrunk from 20 000 to 12 000 tons ? also having the ASEV moniker on the title ?

Aegis system equipped vessels (ASEV) - Wikipedia

en.wikipedia.org

 

[starviking]

Have you considered the possibility that the lack of detail is intentional because details are yet to be settled? I will accept more detailed renders can be found of the proposed ships, but the details presented might just be fillers to give a prettier picture.

My personal experience of Japanese software usage jibes with the ‘old software was available’.

 

[Cordy]

Maybe the thread title could be changed, since the ships have shrunk from 20 000 to 12 000 tons ? also having the ASEV moniker on the title ?

Aegis system equipped vessels (ASEV) - Wikipedia

en.wikipedia.org

Japanese Navy convention is to quote ships displacement in standard tons, which for ASEV is 12,000 tons, but Japanese ministry said that the size of the ASEV with its 128 VLS cells will be 1.7 times larger than the US Navy’s latest Burke Flight III destroyers, the Burke Flt III full load displacement 9,500 mt+ which would make the ASEV near 16,000 mt+ and 190 m length - 25m beam. The JMSDF is expected to take delivery of the first ASEV during FY 2027, with the second one in the following year.

PS The dimensions of the Zumwalt are very similar to the ASEV, displacement 16,000 mt, 186m length 24.6m beam, confirming the ASEV size.

PPS The possible future DDG(X) full load displacement have seen quoted as 13,500 mt.

 

[aonestudio]

Japan MoD signs contracts to build two ASEVs with MHI and JMU - Naval News

On September 18, 2024, the Japanese Ministry of Defense announced that it has signed contracts to build two Aegis System Equipped Vessels (ASEV) for the Japan Maritime Self-Defense Force with Mitsubishi Heavy Industries and Japan Marine United, separately.

www.navalnews.com

 

[Scott Kenny]

Japan MoD signs contracts to build two ASEVs with MHI and JMU - Naval News

On September 18, 2024, the Japanese Ministry of Defense announced that it has signed contracts to build two Aegis System Equipped Vessels (ASEV) for the Japan Maritime Self-Defense Force with Mitsubishi Heavy Industries and Japan Marine United, separately.

www.navalnews.com

Two shipyards is standard practice for Japan.

 

[Dilandu]

Bigger surface ships tried going couple 76mm route in the 1960s...didn't end well.

Well, in modern days with air and surface drones sneaking around, it actually seems that Italians were right, and a battery of several 3-inch autocannons is better than one 4-5 inch turret.

 

[Scott Kenny]

Well, in modern days with air and surface drones sneaking around, it actually seems that Italians were right, and a battery of several 3-inch autocannons is better than one 4-5 inch turret.

With the Italian Supraponte installation, the comparison is that a 76mm CIWS with guided ammo is a lot better for the same installed weight as a 20mm Phalanx CIWS.