Japan to downsize 2 planned Aegis destroyers to increase mobility

Solve the social problems of the country first before playing the little soldier..

One wonders if the decrease in displacement is accompanied by a decrease in other capacities such as anti-submarine warfare or anti-surface warfare capabilities.

not complaining. Just curious.

Solve the social problems of the country first before playing the little soldier..

Survivors (if any) sitting in a smoldering crater, will likely not consider their “social problems” to be very pressing if their cities, government and society have been destroyed.

One wonders if the decrease in displacement is accompanied by a decrease in other capacities such as anti-submarine warfare or anti-surface warfare capabilities.

not complaining. Just curious.

Good question. Look at the question from a tonnage point of view. If you are going to build 40,000 tons of ships, do you build two 20,000 ton ships or five 8200 tons ships? The capabilities are pretty much the same. I would go with more ships. I think that is were they are heading.

Who will give or make the decision to fire one of these missile interceptors? Where's the command and control? It's not much use having this capabiitiy if it is never used. The recent overflights of Kim's tin tubes over Japan don't seem to have created any urge to 'shoot one down'

@Nemo

One wonders if the decrease in displacement is accompanied by a decrease in other capacities such as anti-submarine warfare or anti-surface warfare capabilities.

AN/SPY-7 is much larger, heavier, and power thirstier than earlier AN/SPY-1 Aegis radar, thus requires a much larger hull to mount them.

One solution would be to mount the AN/APY-7 radar low, turn on only 2 out of 4 radar panels, and keep the number of SM-3 missile count low. This would mean the Aegis Ashore destroyer would require an escort of an existing Aegis destroyer to deal with submarines and other incoming low-flying missiles like cruise and anti-ship missiles.

@samit,

Thats about what I was thinking. They’re cutting the displacement by more than 1/2. One would think that there must be a choice to have less ASW capability (in addition to other capabilities.)

AN/SPY-7 is much larger, heavier, and power thirstier than earlier AN/SPY-1 Aegis radar, thus requires a much larger hull to mount them.

No. Since it is an AESA it is easily scalable. The Canadians are mounting AN/SPY-7 on their new "Canadian Surface Combatant". AN/SPY-6 is likewise an AESA and is going to be built in at least four differently sized configurations.

Thats about what I was thinking. They’re cutting the displacement by more than 1/2. One would think that there must be a choice to have less ASW capability (in addition to other capabilities.)

I doubt it. In fact I cannot think of an ASW ship over 10,000 tons. Most ASW frigates, the backbone of ASW, are in the 4,500 to 7,500 ton range, though a new German design is going to nudge 9,500 tons. Because there are occasions where the ship must execute some pretty hard maneuvers at high speed to get close enough to a modern nuclear sub to launch a torpedo that has a chance of reaching a deep diving sub, speed and agility matter. A larger hull with a longer waterline allows higher speeds in heavier seas, an advantage, but only up to a point. Anything much larger than a Spruance/Ticonderoga/Burke/Udaloy class, all of which are premier ASW ships, is going to give up agility attacking subs and has to rely more on its helicopters and stand off weapons like ASROC. And before you shake your head my inclusion of the Ticonderoga class, ask yourself if you have ever been aboard one at full honk when the helmsman throws the wheel over hard left or hard right causing it to heel 20 dgrees while it's throwing a rooster tail of spray higher than the main deck off the stern. They are impressively fast and maneuverable ships.

NK proved that the Aegis system doesn’t work. They fired four missiles simultaneously and it only had the ability to stop three. That means one nuke could hit Tokyo.

totally overpriced and give USA full access to our confidential military intelligence.

@Desert Tortoise

Since it is an AESA it is easily scalable.

1) The AN/SPY-7 model ordered by Japan is a large, powerful land-based radar.

2) Downsizing is not an option because a downsized AN/SPY-7 radar loses anti-ballistic missile capability.

3) Any "order change" requires more time and money.

The Canadians are mounting AN/SPY-7 on their new "Canadian Surface Combatant". 

The Canadian Surface Combatant is a Type 26 frigate with no anti-ballistic missile capability. It cannot operate SM-3 missiles.

In fact, there is a proposal for a US version of the Aegis Ashore ship; it envisions mounting the AN/SPY-6 radar on a San Antonio class hull, a 25,000 ton displacement LPD, or about the size of the proposed JMSDF Aegis Ashore destroyer.

@RodneyToday 

NK proved that the Aegis system doesn’t work. They fired four missiles simultaneously and it only had the ability to stop three. That means one nuke could hit Tokyo.

The best option for Japan is to buy the Korean KAMD triple layer missile defense system. The Korean system has none of the problems that THAAD or Aegis Ashore has because Korea has a similar geographic condition to Japan and was specifically engineered to deal with such issues.

Unfortunately, the best missile defense option is the one Japan cannot take.

There seem to be a lot of blind folded people in Japan, that can't connect the lines. MSDF buying weapons from US. A former MSDF member assassinating Abe. Who had the biggest motive to assassinate him? Well, look at where the money is. Abe was leading the Seiwa-kai, as the grandson of the class A war criminal Nobusuke Kishi, put in place by US due to his anti-communist stance. Abe's brother is the former defense minister. Now, US want to revert their choice of putting fascists as leaders of Japan, to make Japan a viable weapon customer. The head of the snake is assassinated. A ridiculous story about the Unification Church is fabricated, in order to remove Abe's brother, the former defense minister, as well. Other members of the Seiwa-kai are being removed as well, using the Unification Church as an excuse. The only good outcome of this is that the Japanese political system is finally being revamped...

As much as I tried, but I don’t get the point. If a bunch of those attacking missiles is launched and incoming, each with about estimated 10 mixed real and fake nuclear warheads, then you have only a very few minutes to react and to launch whatever amounts of defense missiles you have in possession, because you just can’t and don’t know which of the many incoming beasts are the real ones, and I am very sure, all the ship’s size faster deployment capabilities or maneuvering speed in general doesn’t play any role at all in that very small time frame.

This is pretty sad.

JMSDF's trying to shrink the Aegis Ashore destroyer so that it can be put into Anti-China missions, leaving Japanese mainland exposed to North Korean nuclear ballistic missiles.

So it's the choice between defending US bases on Okinawa or Honshu, but not both.

https://jp.reuters.com/article/idJP2022110801001790

新イージス艦は、政府が断念した「イージス・アショア」計画の代替策として建造される。当初案では北朝鮮を想定して計画されたが、対中国で柔軟運用できる機能が必要と判断したもようだ。

how much price for one outdated rocket from US stock?

how many families could be feeded from that money-aftercovid hard hit families?

why again money have be wasted if here have best army in the world for over 77 years now?

they are ones who should stop any attacks o Japan-right?

if its not their job-just send them home and stop waste our tax money for their costs!

A destroyer at 20,000 tons is more of a Cruiser or even Battleship.

Ticonderoga missile cruisers are 9,800 t (full load)

Zumwalt destroyers are the biggest at 15,907 t.

Pocket Battleships of the German navy in WWII were 16,000 t but later reclassified as Heavy cruisers.

Calling such a ship a destroyer gets it through funding easier than saying your building two Battleships or Cruisers. Maybe attempting to limit concerns of your hostile neighbors by calling them destroyers.

Having said that, the new Hunter class Frigates being built by Australia will be 9,800 long tons and will be the biggest class of frigate in use. Based on the UK type-26 but modified for Australian requirements. Bigger than the Australian Hobart class destroyers in use.

It is all over the place in modern days. You could call it an armed canoe (rather than a destroyer) and nobody would bat an eyelid.

NK proved that the Aegis system doesn’t work. They fired four missiles simultaneously and it only had the ability to stop three. That means one nuke could hit Tokyo.

Would you care to document when this happened? The US has not so far ever tried to engage and shoot down anyone's ballistic missile during a test.

Aegis using AN/SPY-1 radars can track and engage hundreds of targets simultaneously. SM-6 and SM-3 do not need an illuminator for terminal guidance so there is literally no limit on how many engagements Aegis may handle. The limit is magazine size of the firing unit(s).

1) The AN/SPY-7 model ordered by Japan is a large, powerful land-based radar.

2) Downsizing is not an option because a downsized AN/SPY-7 radar loses anti-ballistic missile capability.

3) Any "order change" requires more time and money.

You apparently have no understanding of how an AESA works. Each transmitter/receiver is an independent radar unit. T/Rs can be teamed to create specific waveforms but there can be T/Rs doing different things at the same time, example some creating a scan wave form while others are used as a communications link to the missiles to update their intercept data or to illuminate a target for a missile with semi-active terminal homing like SM-2 or Sea Sparrow. Unlike AN/SPY-1 the T/Rs in an AESA can operate on different frequencies simultaneously. Some T/Rs can conduct a long range scan in S band while others provide target tracking in X band for example. You can also have T/Rs creating wave forms on multiple frequencies at lower power levels to make the radar both less detectable (Low Probability of Intercept) and much harder to jam.

The number of T/Rs in blocks can be increased or decreased as needed to fit the space and weigh margins available. You say AN/SPY-7 is a land based system yet An/SPY-7(V)3 is going to be installed on Canadian warships. Another version of AN/SPY-7 is being fitted to the Spanish Navy's new F-110 class frigates. AN/SPY-7 is also being considered for backfit to existing Arleigh Burk Flight IIA ships to replace their existing AN/SPY-1 radars.

What you call downsizing is a misnomer. The system was designed from the outset to be scalable and may be used with multiple different sized installations on both land and sea based platforms. The version going on ships will be able, according to open sources, discriminate targets half the size AN/SPY-1 can currently discriminate at four times the range, which considering AN/SPY-1s proven capabilities is more than enough for sea based BMD. The US Navy has already shot down an ICBM target using SM-3 Block II from a DDG off Hawaii.

Any change requires time and money, except that these different versions are already planned and being implemented. As I said, the system was designed from the outset for land and naval use.

Calling such a ship a destroyer gets it through funding easier than saying your building two Battleships or Cruisers. Maybe attempting to limit concerns of your hostile neighbors by calling them destroyers.

Japan calls their big deck helicopter carriers like the Hyuga and Izumo classes "Multipurpose Destroyers" and designates them as DDH for basically that reason.

As much as I tried, but I don’t get the point. If a bunch of those attacking missiles is launched and incoming, each with about estimated 10 mixed real and fake nuclear warheads, then you have only a very few minutes to react and to launch whatever amounts of defense missiles you have in possession, because you just can’t and don’t know which of the many incoming beasts are the real ones, and I am very sure, all the ship’s size faster deployment capabilities or maneuvering speed in general doesn’t play any role at all in that very small time frame.

Aegis is fast enough to handle such a raid. AN/SPY-1, Aegis and VLS were designed to defeat mass raids of hundreds of Soviet missiles launched at a carrier strike group from subs, surface ships and bombers each coming at the CSG from different directions. Since then the weapons the ships carry have been improved to increase their speed and range culminating with SM-3 for exoatmospheric intercepts (in space) and SM-6 and possible the most recent version of ESSM for short range point defense. SM-3 Block II, which Japan is co-developing with the US, is probably the longest ranged and highest flying SAM in existence and can hit ballistic missiles in space before they can deploy decoys and warheads. The Aegis battle management system and its radars can handle hundreds of simultaneous intercepts and the radars have the necessary range to track ballistic missiles. SM-3 and especially SM-3 Block II make it possible to defeat enemy missiles in space before they begin their descent to their targets.

Now consider the geography of the region. Having missiles like SM-3 on ships close to North Korea starts to open opportunities for the Holy Grail of missile defense, a boost phase intercept. Nobody is going to get that opportunity with ICBMs launched from silos in western China. But longer ranged ballistic missiles fired from North Korea offer an opportunity for ships near Korea to hit them as they climb, when their speeds are lower and they are not maneuvering.

Ship size and maneuverability have no bearing on BMD but does have a bearing on anti-submarine warfare. These ships would be prime targets for DPRK and PRC subs so ASW capability matters greatly.