DD(X) DDG-1000 Zumwalt-class destroyers

[Forest Green]

USS Zumwalt to receive hypersonic missile upgrades at HII

The destroyer's modernization period includes installation of the Navy’s Conventional Prompt Strike hypersonic missile system.

www.defensenews.com

 

[Christopher Wang]

Since the Zumwalt class DDGs' upcoming Advanced Payload Modules for the Long-Range Hypersonic Weapons (LRHW) are based on the VLS modules used on the Ohio class SSGN and Virginia class SSN, could the same modules which are projected to carry three LRHWs each also carry six or seven Tomahawk cruise missiles?

Let us assume that both of the Zumwalt class DDGs' Advanced Gun System turrets are removed and replaced with eight LRHW modules. And let us assume that each of the LRHW modules has space for six or seven Tomahawks. Combined with the existing 80 cells of the Mk 57 Peripheral Vertical Launch System, each of the refitted Zumwalt class DDGs could carry a total of 128 to 136 Tomahawks which is comparable to the Ticonderoga class CGs.

 

[sferrin]

Since the Zumwalt class DDGs' upcoming Advanced Payload Modules for the Long-Range Hypersonic Weapons (LRHW) are based on the VLS modules used on the Ohio class SSGN and Virginia class SSN, could the same modules which are projected to carry three LRHWs each also carry six or seven Tomahawk cruise missiles?

Let us assume that both of the Zumwalt class DDGs' Advanced Gun System turrets are removed and replaced with eight LRHW modules. And let us assume that each of the LRHW modules has space for six or seven Tomahawks. Combined with the existing 80 cells of the Mk 57 Peripheral Vertical Launch System, each of the refitted Zumwalt class DDGs could carry a total of 128 to 136 Tomahawks which is comparable to the Ticonderoga class CGs.

Why would you when (presumably) any of it's 80 Mk57 cells could? Neither the Zumwalts, or any Aegis ship, would ever fill ALL its cells with Tomahawk.

 

[Christopher Wang]

Why would you when (presumably) any of it's 80 Mk57 cells could? Neither the Zumwalts, or any Aegis ship, would ever fill ALL its cells with Tomahawk.

I'm asking if the Zumwalt DDGs' Advanced Payload Modules could carry other missiles besides the LRHW.

 

[Josh_TN]

I'm asking if the Zumwalt DDGs' Advanced Payload Modules could carry other missiles besides the LRHW.

Perhaps, but why?

 

[Scott Kenny]

Since the Zumwalt class DDGs' upcoming Advanced Payload Modules for the Long-Range Hypersonic Weapons (LRHW) are based on the VLS modules used on the Ohio class SSGN and Virginia class SSN, could the same modules which are projected to carry three LRHWs each also carry six or seven Tomahawk cruise missiles?

Let us assume that both of the Zumwalt class DDGs' Advanced Gun System turrets are removed and replaced with eight LRHW modules. And let us assume that each of the LRHW modules has space for six or seven Tomahawks. Combined with the existing 80 cells of the Mk 57 Peripheral Vertical Launch System, each of the refitted Zumwalt class DDGs could carry a total of 128 to 136 Tomahawks which is comparable to the Ticonderoga class CGs.

Assuming that it's an 85" inside diameter tube to support the VPM units, it's theoretically possible.

Perhaps, but why?

To allow those 80x Mk57s to be filled with SAMs?

 

[Christopher Wang]

Perhaps, but why?

The Long-Range Hypersonic Weapon (LRHW) would be a useful addition to the Zumwalt DDGs, but it would be a wasted potential if the Advanced Payload Modules (APM) are restricted to only one type of missile.

Assuming that it's an 85" inside diameter tube to support the VPM units, it's theoretically possible.

All the news reports I have read confirm that the APMs have a diameter of 87 inches, so you may be right.

 

[yeetmahboi]

but it would be a wasted potential if the Advanced Payload Modules (APM) are restricted to only one type of missile.

I dont see how, really.
APM is, or rather should, be developed from the VPM system so built in magazine modularity should be a starter. That being said, what Im getting from the DDGX render is that one 32-cell module can be exchanged for one APM. APM's 3-tube, lets assume each holds 7 Tomahawk, gives a max loadout of 21 Toma-sized munitions. Thats worse than the standard 32 cell, so the sole benefit to fitting APM is that you can use CPS?

For whatever's worth, I think squeezing out the potential of the Mk41, like giving new batches a dual hot/cold launch system that also permits the use of full-sized systems, improve maintainability, etc would be better than chasing other alternatives. In that sense, APM is good because its where oversized payloads get relegated to.

SM-3 Blk IIB should be a good basis to build a small HGV-tipped missile, while NGLAW, slated to replace the Tomahawk, should fit inside the constraints of Mk41, and SM-6 still is the most capable naval SAM at the moment relative to its competition.

 

[Scott Kenny]

I dont see how, really.
APM is, or rather should, be developed from the VPM system so built in magazine modularity should be a starter. That being said, what Im getting from the DDGX render is that one 32-cell module can be exchanged for one APM. APM's 3-tube, lets assume each holds 7 Tomahawk, gives a max loadout of 21 Toma-sized munitions. Thats worse than the standard 32 cell, so the sole benefit to fitting APM is that you can use CPS?

Again, the Zumwalts have 80x Mk57 cells. So swapping one or both AGS for APMs doesn't hurt AA self defense capability.

Side note, I am actually expecting the APMs to only hold 6x birds, the center tube is the wiring access point for VPMs. But not for the Trident version.

 

[Moose]

Again, the Zumwalts have 80x Mk57 cells. So swapping one or both AGS for APMs doesn't hurt AA self defense capability.

Side note, I am actually expecting the APMs to only hold 6x birds, the center tube is the wiring access point for VPMs. But not for the Trident version.

The payload tubes in the bow of a block III+ 774 aren't accessible from the pressure hull, being located in a ballast tank, so loading requires access via the center. But the tubes in the Block V/VI VPM can be accessed from the pressure hull just like in a SSGN, so they can take a full load of 7. Barring some really problematic flooding, these DDG tubes will be accessible.

 

[Scott Kenny]

The payload tubes in the bow of a block III+ 774 aren't accessible from the pressure hull, being located in a ballast tank, so loading requires access via the center. But the tubes in the Block V/VI VPM can be accessed from the pressure hull just like in a SSGN, so they can take a full load of 7. Barring some really problematic flooding, these DDG tubes will be accessible.

Fair point.

 

[yeetmahboi]

Again, the Zumwalts have 80x Mk57 cells. So swapping one or both AGS for APMs doesn't hurt AA self defense capability.

Side note, I am actually expecting the APMs to only hold 6x birds, the center tube is the wiring access point for VPMs. But not for the Trident version.

Yes, I'm all in for replacing both AGS mounts with APMs.
The thing here is the possibility of modular magazines in APM, which I believe will be used on the DDGX while Mk41 is kept for legacy reasons. I see no use in additional capability because existing systems like Standards are perfectly usable for everything except carrying hypersonics, and CPS is matured enough that it will be the main strategic LRPF onboard USN LSCs in the foreseeable future.

 

[Firefinder]

Honestly there is one other missile type I can see the APMs being use for.

A new version of the Kinetic Energy Interceptor.

That system was basically the same size, 40 inches diameter and bout 39 foot long, as the Long-Range Hypersonic Weapon (LRHW).

So I can see that bring that back for the ABM job in the future.

Not much use for the Zumwalts through, they lack the needed radar size to use such a beast. Could be the shooter to another ship's spotter though.

 

[Josh_TN]

Honestly there is one other missile type I can see the APMs being use for.

A new version of the Kinetic Energy Interceptor.

That system was basically the same size, 40 inches diameter and bout 39 foot long, as the Long-Range Hypersonic Weapon (LRHW).

So I can see that bring that back for the ABM job in the future.

Not much use for the Zumwalts through, they lack the needed radar size to use such a beast. Could be the shooter to another ship's spotter though.

The future USN interceptor is likely Glide Breaker. No idea what the dimensions are, but I suspect it will be mk41 sized. APM is best used for CPS, since there will be such a limited number of tubes for it in the fleet and Zoomie isn’t really useful for anything else. The VPMs might contain Sea dragon.

 

[that_person]

ZEUS upgrades are coming up soon too

 

[Scott Kenny]

The future USN interceptor is likely Glide Breaker. No idea what the dimensions are, but I suspect it will be mk41 sized. APM is best used for CPS, since there will be such a limited number of tubes for it in the fleet and Zoomie isn’t really useful for anything else. The VPMs might contain Sea dragon.

I'm not sure you can get any decent HGV protection footprint out of a Mk41 sized missile.

 

[Josh_TN]

I'm not sure you can get any decent HGV protection footprint out of a Mk41 sized missile.

I’m not sure there will be enough platforms to mount it on otherwise.

 

[that_person]

I'm not sure you can get any decent HGV protection footprint out of a Mk41 sized missile.

Glide Phase Interceptor is trying to do just that

 

[Scott Kenny]

I’m not sure there will be enough platforms to mount it on otherwise.

Remove 16x Mk41 cells and replace with 2x or 3x APM tubes, whichever fits.

Glide Phase Interceptor is trying to do just that

The last HGV interception chart I looked at gave a horizontal range of 7nmi from launcher to edge of NEZ. That makes typical naval dispersion wide enough that each ship will have to carry its own HGV interceptors. Can't stack all the ships within a 7nmi bubble and be safe from the other missile attacks.

 

[that_person]

Remove 16x Mk41 cells and replace with 2x or 3x APM tubes, whichever fits.



The last HGV interception chart I looked at gave a horizontal range of 7nmi from launcher to edge of NEZ. That makes typical naval dispersion wide enough that each ship will have to carry its own HGV interceptors. Can't stack all the ships within a 7nmi bubble and be safe from the other missile attacks.

Japan Joins U.S. for Glide Phase Interceptor (GPI) Development - Naval News

Japan's Ministry of Defense announced that Japan & the United States agreed to start the joint development of the GPI

www.navalnews.com

There’s an SM-6-sized missile program running to fit a HGV interceptor into a Mk41. It’s mature enough that Japan joined too.

 

[Scott Kenny]

Japan Joins U.S. for Glide Phase Interceptor (GPI) Development - Naval News

Japan's Ministry of Defense announced that Japan & the United States agreed to start the joint development of the GPI

www.navalnews.com

There’s an SM-6-sized missile program running to fit a HGV interceptor into a Mk41. It’s mature enough that Japan joined too.

Still means that each ship will have to carry its own GPIs, and that cuts into other defensive missiles.

 

[Josh_TN]

Remove 16x Mk41 cells and replace with 2x or 3x APM tubes, whichever fits.

Not going to work. CPS is a *lot* longer than a mk41 cell so APM must penetrate an extra deck through the ship. In the case of Zommie, this area was reserved for the ammunition handling of the 155mm, so the room is there. That would not apply for any Mk41 equipped ship. Glide Breaker perhaps could be wider than a Mk41 cell but not any longer, so perhaps some kind of modification would be possible. But given all the Mk41s in service and the fact that LSC is a decade or more away, I suspect whatever come from the program is shoehorned into Mk41.

 

[Josh_TN]

The last HGV interception chart I looked at gave a horizontal range of 7nmi from launcher to edge of NEZ. That makes typical naval dispersion wide enough that each ship will have to carry its own HGV interceptors. Can't stack all the ships within a 7nmi bubble and be safe from the other missile attacks.

Not sure about that...my understanding is that the intent of Glide Breaker was to engage incoming HGVs at extended ranges before they started maneuvering. That would presumably involve an interceptor with a very large engagement envelope.

 

[that_person]

Still means that each ship will have to carry its own GPIs, and that cuts into other defensive missiles.

Zumwalt doesn't seem to be getting that much of an AAW armament. Her SPY-3s are only being replaced with the 9-foot SPY-6s. She's a strike platform.

 

[trose213]

Zumwalt doesn't seem to be getting that much of an AAW armament. Her SPY-3s are only being replaced with the 9-foot SPY-6s. She's a strike platform.

Doesn't need much with how long range the CPS is.

 

[that_person]

Doesn't need much with how long range the CPS is.

I have no idea what you're talking about

 

[Josh_TN]

I have no idea what you're talking about

The US Army states that LRHW has a 1750 mile range. That would mean the launch platform could be a couple time zones away from the target, so the threat environment is likely rather moderate. In the context of a Pacific war, it is unlikely that a Zoomie is ever in range of anything smaller than a DF-26.

 

[Scott Kenny]

Not sure about that...my understanding is that the intent of Glide Breaker was to engage incoming HGVs at extended ranges before they started maneuvering. That would presumably involve an interceptor with a very large engagement envelope.

Don't know how they're going to stuff the required thrust into a 21" diameter missile, short of something really weird like the Meteor solid fuel ramjet but as a scramjet.

Actually, can't an ATACMS fit into a Mk41, if barely? I know they fit into submarine VLS tubes with minimal modifications. That means a 24.5" missile, which will help a lot.

Zumwalt doesn't seem to be getting that much of an AAW armament. Her SPY-3s are only being replaced with the 9-foot SPY-6s. She's a strike platform.

The way I'm seeing it, the GPIs are going to be pretty close in usage to ESSMs or maybe SM2MRs. Higher altitude capabilities and faster, but not a lot of distance from the ship horizontally. Kinda like the difference between Hydra rockets and CRV7s: Hydra has 2.5x more range, CRV7s are a lot faster.

As the Blackbirds demonstrated, intercepting a Mach 3+ target is very difficult even when it goes in a straight line. You need a long detection range from your sensors and a missile that climbs to altitude very quickly. Any maneuvers at all can completely ruin any chance of intercepting the Blackbird, their usual response to "missile launch detected" was to push on the throttles and make a pretty gentle turn, maybe 2 gees at the most (Max turn was a 3.5gee).​

Honestly, something like the old Sprint ABM has the kinematics to get up fast enough, but is way too big to fit into a Mk41. Sprints were 53" in diameter at the base!

I'm expecting a 3 stage missile: booster/first stage is to punt the missile far enough from the ship that when the insane second stage kicks in the ship isn't damaged. Second stage pushes 100+gees up and as a side effect gets the missile up to some 3000m/s. Third stage is for terminal impact.

 

[Josh_TN]

Take a look at THAADs dimensions. That’s an endo/exo atmospheric missile with a slant range in the low hundreds of km. Any hypersonic glider by definition is still faintly inside the atmosphere. Anything above that is just ballistic. So it seems to me that something mk41 compatible but with a higher divert ability is possible. As for effective engagement angles…the defending ship probably needs to the target, next to the target, or down the threat axis. For an escorted target, it seems likely there is at least one close defender and likely at least one in envelope defense platform further out, at least for land launched missiles where the threat axis is pretty obvious and static.

 

[trose213]

The US Army states that LRHW has a 1750 mile range. That would mean the launch platform could be a couple time zones away from the target, so the threat environment is likely rather moderate. In the context of a Pacific war, it is unlikely that a Zoomie is ever in range of anything smaller than a DF-26.

And that's just the acknowledged range, not the true one.

 

[Josh_TN]

And that's just the acknowledged range, not the true one.

Yes, that’s the distance from Guam to Taiwan without threatening the mainland range.

 

[yeetmahboi]

Don't know how they're going to stuff the required thrust into a 21" diameter missile, short of something really weird like the Meteor solid fuel ramjet but as a scramjet.

A dual-stage ramjet for efficient acceleration at different speed regimes and sustained M7 at altitude could allow enough energy to lob an KKV. Or supersonic combustion rockets. Essentially recreating Sprint in the 21st century?

 

[Josh_TN]

I don’t think a ramjet of any kind is practical. Reaction time and altitude are an issue; I think both rule out a ramjet or even scramjet option, even if some kind of weird solid boosted, scramjet sustained, solid terminal engagement weapon was technically achievable.

 

[Scott Kenny]

I don’t think a ramjet of any kind is practical. Reaction time and altitude are an issue; I think both rule out a ramjet or even scramjet option, even if some kind of weird solid boosted, scramjet sustained, solid terminal engagement weapon was technically achievable.

My mental model was solid boosted, solid first stage, and scramjet terminal. The booster is fairly small, just enough to get the first stage to minimum safe distance before ignition.

Apparently THAAD is a 13" rocket with a 15" business end? I don't think that you'd have the full 200km cross range against a target that isn't coming directly towards the launcher, though. Are any THAADs in Ukraine, or just Patriots?

Something THAAD-like could be the GPI, though I'm betting more towards the proposed THAAD-ER with a 21" booster. If you can't double-pack into a Mk41 cell, you might as well use all available diameter!

 

[Josh_TN]

My mental model was solid boosted, solid first stage, and scramjet terminal. The booster is fairly small, just enough to get the first stage to minimum safe distance before ignition.

Apparently THAAD is a 13" rocket with a 15" business end? I don't think that you'd have the full 200km cross range against a target that isn't coming directly towards the launcher, though. Are any THAADs in Ukraine, or just Patriots?

Something THAAD-like could be the GPI, though I'm betting more towards the proposed THAAD-ER with a 21" booster. If you can't double-pack into a Mk41 cell, you might as well use all available diameter!

Not sure that is an achievable goal at the altitudes we are discussing. The target itself is not dependent on atmosphere for oxidizer. Things like HAWC/HACM seem to operate at lower altitudes than gliders. They are generally labeled 70,000+ feet. A practical higher scramjet seems like an entire path of research that might need to be undertaken. Minimally, boosting a liquid fuel at those accelerations seems problematic to me. Basing that stack on a ship seems like it might open up other USN concerns as well.

Inaccurate Wiki entries not withstanding, THAAD has an envelope that is pretty large. I think that 200km range involves basically no cross range movement, but if you're defending yourself or the ship next to you, what cross range do you need?

Ukraine has apparently been given almost every flavor of MIM-104: PAC2 GEM, PAC3, MSE. THAAD is definitely not in play, in fact I don't think the US keeps one anywhere in Europe.

An extended range THAAD with more divert seems like a perfectly acceptable anti HGV system, but that isn't the contractor that was selected. So who knows what Glide Breaker ends up looking like. But I suspect it will have a 21" max diameter.

I'm sure the maximum altitude for THAAD basically is point defense only and the maximum range is at its minimum operating altitude, but it seems like a fairly long ranged piece of kit. Seems like it could be had for HGV intercept. The SM-3/6 stack is only moderately heavier, and SM-3 is purely exo atmospheric. I think Mk41's could support a reasonably ranged defensive weapon.

 

[Scott Kenny]

Not sure that is an achievable goal at the altitudes we are discussing. The target itself is not dependent on atmosphere for oxidizer. Things like HAWC/HACM seem to operate at lower altitudes than gliders. They are generally labeled 70,000+ feet. A practical higher scramjet seems like an entire path of research that might need to be undertaken. Minimally, boosting a liquid fuel at those accelerations seems problematic to me. Basing that stack on a ship seems like it might open up other USN concerns as well.

Fair point, the USN is just about anaphylactic allergic to liquid fueled missiles onboard ship, unless the fuel is basically JP5/JP10. Nothing super reactive.

Inaccurate Wiki entries not withstanding, THAAD has an envelope that is pretty large. I think that 200km range involves basically no cross range movement, but if you're defending yourself or the ship next to you, what cross range do you need?

If defending yourself, no cross range needed. But "the ship next to you" in a modern combat formation is going to be over the horizon from you, some 50km away.

That's where my concern about cross range of the GPI are coming from.

An extended range THAAD with more divert seems like a perfectly acceptable anti HGV system, but that isn't the contractor that was selected. So who knows what Glide Breaker ends up looking like. But I suspect it will have a 21" max diameter.

I said "THAAD-like". Even if LockMart isn't the one making the GPI, I still think the final product will look a lot like THAAD-ER.

I'm sure the maximum altitude for THAAD basically is point defense only and the maximum range is at its minimum operating altitude, but it seems like a fairly long ranged piece of kit. Seems like it could be had for HGV intercept. The SM-3/6 stack is only moderately heavier, and SM-3 is purely exo atmospheric. I think Mk41's could support a reasonably ranged defensive weapon.

Reasonable range as long as the ship launching Glide Breaker is the target or on the Threat Axis. Cross range rapidly goes to "minimal" given the speeds and altitudes involved. Especially when the HGV can maneuver. It takes a minimal energy maneuver to get a Mach 3 vehicle out of the intercept bucket of pretty high end air defenses.

 

[Josh_TN]

I’m assuming any high value unit has an escort riding shotgun and that any other warship defends itself, with soft kill measures only if necessary. Area defense against ballistic and hypersonic threats just isn’t going to be practical.

 

[yeetmahboi]

I don’t think a ramjet of any kind is practical. Reaction time and altitude are an issue; I think both rule out a ramjet or even scramjet option, even if some kind of weird solid boosted, scramjet sustained, solid terminal engagement weapon was technically achievable.

I guess I'll have to wait for SABRE then.
Air-augmented rockets present a good interim solution in that they can operates from zero air speed and at high altitude where air is to thin to compress. Wikipedia says Meteor features that kind of propulsion, no idea on validity. But I remember there was a Soviet ICBM project that used AARs, Gnom was it name, and this really deserves further exploration imo. Single-stage-to-orbit airbreathers would be revolutinizing BMD whose history consists solely of overweight rockets bar SM-3.
Alternatively, if you don't mind magazine capacity, converting IR-CPS AURs to take a KKV would be interesting. Arclight reverse?

If defending yourself, no cross range needed. But "the ship next to you" in a modern combat formation is going to be over the horizon from you, some 50km away.

That's where my concern about cross range of the GPI are coming from.

Suppressed glide is a real killer.
I wonder if, at the altitude GPI is supposed to operate in, assuming no MOKV tech, endoatmospheric intercepts could be conducted by ESSM-sized missiles. A 2-stage MALI, with the first stage housing pop-out wings and an improved economy microturbojet, jettisonable, and the second stage a HALFRAAM, but with a smaller motor, and the radome+warhead is replaced by a lightweight KKV. Think of it as a fusion between ALARM, NCADE and the Iranian 358.
Another solution would be to task F-35s, and in the future F/A-XX, to carry out fleet BMD using a combination of their own kinematics and JATMs converted to house KVs. It would require transforming the entire fleet architecture and doctrinal defensive aviation employment, but materially and technologically speaking would be cheaper.

 

[Scott Kenny]

I’m assuming any high value unit has an escort riding shotgun and that any other warship defends itself, with soft kill measures only if necessary. Area defense against ballistic and hypersonic threats just isn’t going to be practical.

And those escorts won't be particularly close to the ship. Look at all the satellite photos of the Ford when the Israel-Hamas fight kicked off. No other ships in the same frame with the carrier. That's the kind of spacing we're talking about for modern missile defenses, which makes it very difficult for any ship but the one being targeted to engage HGVs.

Suppressed glide is a real killer.
I wonder if, at the altitude GPI is supposed to operate in, assuming no MOKV tech, endoatmospheric intercepts could be conducted by ESSM-sized missiles. A 2-stage MALI, with the first stage housing pop-out wings and an improved economy microturbojet, jettisonable, and the second stage a HALFRAAM, but with a smaller motor, and the radome+warhead is replaced by a lightweight KKV. Think of it as a fusion between ALARM, NCADE and the Iranian 358.
Another solution would be to task F-35s, and in the future F/A-XX, to carry out fleet BMD using a combination of their own kinematics and JATMs converted to house KVs. It would require transforming the entire fleet architecture and doctrinal defensive aviation employment, but materially and technologically speaking would be cheaper.

It's honestly not that big a transformation from the original Fleet Air Defense mission IMO. You're just adding weapons to engage a new threat type. Going from multiple bomber regiments to HGV/AShBM defenses.

 

[Josh_TN]

And those escorts won't be particularly close to the ship. Look at all the satellite photos of the Ford when the Israel-Hamas fight kicked off. No other ships in the same frame with the carrier. That's the kind of spacing we're talking about for modern missile defenses, which makes it very difficult for any ship but the one being targeted to engage HGVs.

I would not consider that deployment to indicative of a 7th fleet CSG during hostilities. The only reasons to disperse are 1) to complicate opponent scouting / targeting 2). ASW and 3). nuclear weapons. Those may or may not be relevant in the Pacific theater: overhead surveillance is likely ubiquitous, submarines likely are thin on the ground at the range the USN could reasonably strike PLAN assets (~1000 miles), and tactical nuclear escalation may seem unlikely, at least initially. In fact, pre conflict, it can be assumed all units are continuously tracked, so dense packing of surface units with an ABM capability (and likely ASAT capability by extension) seems perfectly reasonable to me. In any case, I wouldn’t assume the Fords formation typical: I thought it was relatively unheard of for the SAM boss to be more than 3000 yards from the CV, and I think it often acts as the plane guard as a result. But I never was the service so my info is generally third hand.