The Navy’s trend in ship design has been towards lighter and
lighter built ships with less and less defensive capabilities. Well, let’s step in and put a stop to
that! Since the Navy clearly doesn’t
know how to design a ship with defensive capabilities, let’s do it for them.
We’re all familiar with the concept of a carrier group’s
layered defense. Aircraft provide wide
ranging defense against search aircraft and provide the initial defensive layer
against an attack. Standard missiles
offer the possibility of very long range intercepts. Escort ships range dozens of miles out to
provide extended ASW and AAW protection.
Medium range defense is provided by closer escorts and medium range
defensive missiles. Various missiles,
electronic warfare systems, and CIWS provide close in defense.
Similarly, an individual ship’s defense should consist of
more – much more! – than just Standard/ESSM missiles and one or two RAM/SeaRAM,
as the Navy seems to believe. A ship’s
defense should be a multi-faceted, layered construct. Let’s consider the individual components.
Outer Layer
Middle Layer
Inner Layer
A few supplementary comments are warranted:
Sensors – 360 degree EO/IR with targeting capability (IRST)
in addition to supplement and largely replace radar. Such a system would involve far more than the
current one EO sensor on ships today.
This would be several, perhaps dozens, of sensors each scanning a
portion of the sky and acting as a single, integrated system. During war, this may actually be the main
sensor system so that the ship doesn’t have to radiate.
UAVs – This has been posted on previously. Every ship should sail with several dozen
small, stealthy, passive UAVs for establishing situational awareness. These are cheap and expendable. They must be stealthy. It’s pointless to try to establish
situational awareness if doing so gives away your own position. We must be able to see without being seen.
Long range missiles – I hesitate to even include long range
missiles as I believe their use will be quite limited, bordering on never. No enemy is going to present high altitude
targets other than ballistic missiles which are a special case. So many people forget that long range
missiles can only engage high altitude targets because of the radar horizon
limitation. Beyond the radar horizon,
radar can only see targets at altitude.
Close In – Attackers will get through. It’s guaranteed. Even in scripted exercises, they always
do. Every ship should have several to
dozens of close in weapon systems instead of the nearly useless single (or no!)
close in weapon on today’s ships.
Inner Layer - The inner layer has the most components and
yet the Navy devotes the least amount of effort and resources to it. The Zumwalt has no close in weapons. The DDG(X) concept graphic has only two RAM
launchers for close in defense. The
Burkes have only one CIWS.
EW/ECM is the most common and, historically, the most
effective anti-air component and yet the Navy devotes very little attention or
resources to it. Even the current SEWIP
upgrades are a limited effort, poorly executed.
Focus - So, what does the Navy focus its attention and
resources on? That’s right, the most
expensive and least likely to be used component: long range missiles.
- UAVs – small, stealthy, wide ranging UAVs providing passive aerial sensor coverage
- Standard Missiles – long range anti-air defense
- Passive Sonar – long range detection
- EO/IR – long range visual and infrared detection integrated into a 360 deg hemispherical sensor system
- ESM – very long range signals analysis (Outboard/COBLU and S-3 Shadow type sensing) providing detection and triangulation
- Stealth – do all the above without, in turn, being detected
- EO/IR - medium range visual and infrared detection integrated into a 360 deg hemispherical sensor system combined with fire control
- ESSM – medium range anti-air defense
- EW/ECM – detection, jamming, spoofing, etc.
- Stealth – do all the above without, in turn, being detected
- EW/ECM – point defense jamming, spoofing, etc.
- RAM/SeaRAM – close in anti-air defense
- CIWS – close in anti-air defense
- Decoys – integrated into Aegis
- Stealth – do all the above without, in turn, being detected
The USN has been dysfunctional since forever. Its been almost 49 years since I first reported to boot camp. The faces at the top have changed but the mindsets have not. For cripes sake we are still building DDG 51s a design that dates to 1980!!! Steel first cut December 1988. But commissioned on July 4th, 1991. Amazing.
ReplyDeleteSorry posted before done. Operator error. But even that ship was criticized by all the compromises imposed thanks to politics and a fairly long gestation as a result. At least they didnt draw out the construction. Will the USN ever build a suitable and useful Surface Combatant in a reasonable timeframe? Odds are poor.
DeleteLong range missiles can be useful using the Cooperative Engagement Capacity when the outer screen detects and feed the targeting info to the cruisers. By the time the target gets into the cruiser's detection range the missile is in the air and closing on the target. The radar on the missile could also lock on to the target. The E-2Ds can add to that as well for low level. Drones as missile trucks could be fed solutions by the screens too.
ReplyDeleteI know there is that problem of emissions but its at least a part of the defense system.
Or ... and stay with me on this ... the outer screen, since they've detected the target, simply engages it directly! No need for some convoluted series of targeting handoffs, communications noise giving away positions, and a multi-link kill chain that has a higher chance of failure.
Delete"The E-2Ds"
This post is talking about surface ships. For carriers, the aircraft would, of course, add a further, very long range defensive layer.
Something to consider is that EASR AESA radar on the Constellations is an AAW-grade radar. It seems obvious to me that we should be using these ships in the battlegroup as forward pickets, the way Fletchers were in the Big Blue Blanket: the FFGs turn their radars on, radiating and acting as missile bait, feeding targeting picture to the DDGs in the inner layer. That's how you get some use out of long range missiles when your own sensors are limited by the horizon.
DeleteOr, I suppose, counterintuitively, maybe the FFGs should be the inner screen, to provide close ASW protection to the carrier, and to be the final layer of defense? I recall the JMSDF practice, where they have the DDG providing area AAW defense for the squadron, while an AESA FFG provides short range missile defense for itself and the DDG, and the rest of the DDs and DEs have self protection point defense for leakers the DDG missed.
One thing to bear in mind is that radar sensitivity scales as a cube of the size of the radar aperture so if used the smaller SPY-6 in Constellation as a picket ship it would give only fairly poor diffraction beam width of thee point eight degrees due to the small size of the antenna, limited range and though EASR enables it to receive the returns more clearly with low power it makes it much easier for an enemy to inject their own noise via jamming and to swamp the real returns compared to a high power radar which can burn through.
Delete"FFGs turn their radars on, radiating and acting as missile bait, feeding targeting picture to the DDGs in the inner layer."
DeleteIf the FFG has the target on radar, why wouldn't it engage the target itself? Why unnecessarily complicate the kill chain? This kind of thing is technology for the sake of technology.
"If the FFG has the target on radar, why wouldn't it engage the target itself? Why unnecessarily complicate the kill chain?"
DeleteBut of course! The whole point of CEC and the fight being quarterbacked by the Air warfare commander in the CG is so that everyone can be engaging and coordinating their fires, and FFGs do carry interceptor SAMs of their own.
The biggest argument against having them on the outer edge of the screen, though, is their limited magazine depth: The Constellations have a third the VLS cells of the Burkes. So, like I said, perhaps that's where they should be - the inner screen, providing the second layer of defense to the carrier, bodyguarding it the way the Japanese use their AESA DDs to bodyguard their DDGs.
"The biggest argument against having them on the outer edge of the screen, though, is their limited magazine depth:"
Delete???? Smaller escorts are farther out because they're smaller! That means they're expendable. They provide an expendable means of early detection as well as ASW. Reversing the system and putting the more powerful Burkes on the outer screen would simply be sacrificing powerful units to submarines and missiles.
https://www.navalnews.com/naval-news/2024/02/us-navy-awards-sewip-block-3-backfit-on-more-destroyers/
ReplyDeleteThis block has electronic attack capability. Block 4 is a future upgrade. Passive defense is another layer of defensive capabilty & I see that you have a post on this.
Do you know if there has been any work- -even just theoretical computer simulations- on using large guns with high explosive shells, aimed by modern fire control systems, to take out missiles? It seems like that would be an elegant solution- you use the big guns to take out mass swarms of missiles or drones, then use interceptor missiles or CIWS to take out individual missiles that leak through. But as far as I know this has never been explored as a modern option.
ReplyDeleteWell, that exact concept was explored on this blog (see, "Return of the Broadside")
DeleteThe Japanese used this tactic with little success in WWII. Since we have no big guns today, no one is looking at it except us!
@Aj Gyes: The Italians have been working on this for the last decade and change with the OTO Melara 76mm gun. Live fire tests have demonstrated the ability to engage fairly small target drones that are an order of magnitude smaller than cruise missiles. It's worth noting that 3" shells have a significantly faster muzzle velocity than RAM, which gives them a greater effective range (on account of intercepting the target faster than RAM).
DeleteThe Chinese are also doing their own research into medium-caliber point defense guns - I've seen research papers to that effect, where using very conservative performance metrics (significatly below the demonstrated capability of DART), the calculations show that they can guarantee target destruction with a salvo of 12 rounds in the worst case scenario.
However, it would appear that the Chinese have decided to pursue high powered lasers instead.
Interestingly, the Japanese railgun program is for a pretty modest railgun weapon, in the 25mm to 40mm range, with the intent of using it as a point defense gun against missiles (as opposed to the American railgun programs which were about shore bombardment).
There was a proposal in Proceedings I think a few decades ago about using Battleship 16-in guns for missile defense using airburst ammo.
DeleteI once suggested something similar with big rockets.
http://www.g2mil.com/NAVROC.htm
"Live fire tests have demonstrated the ability to engage fairly small target drones that are an order of magnitude smaller than cruise missiles."
DeleteI am unaware of any semi-realistic testing of 76 mm guns against cruise missiles. I'm aware of manufacturer's tests against static targets (with a static gun mount!) or very slow flying drones. I'm unaware of a test against an actual cruise missile with terminal evasive maneuvering and possible penaids while the defending ship is sailing at high speed and maneuvering radically in choppy seas and, perhaps, rain. Do you know of any tests? Manufacturers can, and do, make all manner of claims that are invariably false or, at best, vastly overstated.
Point defense intercept boils down to two variables: target size and target speed.
DeleteNote that the test shoots of the 76mm DART system were against small Banshee target drones, which are a fraction of the size of the seaskimming Kalibr missile (a Kalibr is 4 times the size of a Banshee).
The manufacturer's test demonstrate that the entire package is capable of servicing the first variable; what's not demonstrated is the second variable. Still, you have 72 rounds of ready ammo, you at least can take more shots at the target.
"test shoots"
DeleteI've never yet seen a test shoot that was remotely realistic. Do one against a supersonic or high subsonic missile capable of wild terminal maneuvers while the defending platform (ship) is wildly maneuvering in high sea states and then I'll begin to believe the results.
Honest question here: how wildly can a missile fly in terminal engagement and for how long? At some point, it has to settle out its flight path.
DeleteI flew Hueys in Nam, and we were flying wild as you please. I flew so low my skids were bashing the treetops. And I was always concerned because no matter how crazy I flew, there was always that one moment when I was completely vulnerable to enemy fire: when I settled in to fire. It was only for a few seconds, just long enough to let loose a salvo of rockets, but it was the most terrifying moment of my life. And then I did it again, and again, and again.
"how wildly can a missile fly in terminal engagement"
DeleteModern missiles are designed to execute a convoluted "corkscrew" approach which may or may not be combined with a terminal pop-up and steep dive final maneuver. Somewhere I once saw a graphic of the head on view of a missile on terminal approach and it looked like random, chicken scratchings all over the page - very tough to predict or get a clean shot at!
"there was always that one moment when I was completely vulnerable to enemy fire: when I settled in to fire."
While true for helos, a missile doesn't need to "stop". It just keeps coming. It can approach the target from a steep angle just as well as straight on (90 deg).
Question for you - is armor compatible with stealth? Could an additional defensive layer be added that consists of armor, but that does not compromise stealth? I am thinking mainly of the magnetic signature of ferrous metals that traditionally make up armor, but also possible shaping difficulties.
ReplyDelete"is armor compatible with stealth?"
DeleteWhy wouldn't it be?
"I am thinking mainly of the magnetic signature "
This has been well understood and dealt with since WWII. Degaussing is the process by which a ship's magnetic signature is reduced or eliminated.
Add depth and division of armor and that completes the picture. Not unsinkable but not mission kill by default.
ReplyDeleteAgain, compartmentation and armoring have been well understood since very early times.
Delete"Again, compartmentation and armoring have been well understood since very early times."
ReplyDeleteExcept by the modern US Navy. ;)
Lutefisk
I stand corrected.
DeleteFun fact: it's actually possible to see the thermal bloom of an approaching sea skimming supersonic missiles through an IR camera, past the horizon. Thruster wash and friction heats the air, creating an effect not disimilar from watching the rays of the sun rising above the horizon at dawn. Of course, at that point, the missile is impacting in seconds. Better hop to it.
ReplyDeleteYour fun fact seems to reinforce CNO's idea (hopefully summarizing correctly) that engagements are more likely to be horizon types of quick reaction engagements rather than the long-range radar/missile intercepts using Aegis and Standards.
DeleteLutefisk
The final defense is damage control. Make sure every sailor is up to speed and capable of participating in DC. As an aside, at the risk of sounding anachronistic, how effective are female sailors at the physical tasks required of DC in a fire/flood/hull breach scenario. Has this been studied?
ReplyDeleteLong range missiles need to be there almost as a fleet in being. If there was none, then the enemy could fly high safely at points. They need to be there to keep them honest.
ReplyDeleteI think the elephant in the room is wondering how effective any of these systems will be in actual combat.
ReplyDeleteThe situation in which the navy puts only one phalanx on the Burke, and apparently is phasing it out in favor of a SeaRAM, is a bit concerning.
If the navy was a disciplined, testing and data driven, lets make the best navy that we can to win in combat type of organization, I'd assume that CIWS isn't really all that effective so they have deemphasized it.
But can anybody say with confidence that the US Navy is that type of organization? I know I don't feel that way.
It looks like the navy doesn't know how well these systems will perform in combat, what effects missiles have on armor, how important is EMCON on the modern oceanic battlefield, and really anything else that is practical.
I wonder what their priorities are? Because winning the next naval war doesn't seem to be on the list.
Lutefisk
The Japanese seem to always have two phalanx mounts on their ships. Do they think they're effective because of their own testing, or are they relying on ours?
DeleteOne of the problems with CIWS placement on FFGs and DDGs is that if you place them too close, their search radars will interfere with each other. Note where the Iowa's placed them: at the bow, under the bridge, next to the directors, and aft by the funnel. The director is acting like a break, a blindspot, that's reducing emissions interfering with each other. Note placement on the Burkes: one forward, under the bridge, one aft above the helo hangar: there's the entire superstructure in between.
DeleteOn the other hand, adding additional RAM mounts (as opposed to SeaRAM) is a much easier proposition: the 21-cell RAM launcher is purely passive, relying on the host ship's radar and FCS to cue it. It has no emissions, so there's no emission interference to worry about. Consider the Spruances - the VLS Spruances had 2 Phalanx CIWS, an 8-cell Sea Sparrow launcher, and a 21-cell RAM launcher. You could easily swap the Sea Sparrow launcher for another RAM launcher with no problems - just make sure to clear backblast.
I'm told that one of the reasons the Chinese are seriously pursuing laser CIWS is because lasers don't have the same backblast issues with point defense missiles, which means that if you had enough power generation and cooling, you could stack a greater density of point defense lasers than you could missiles or autocannons. (Assuming that your AESA radar remains intact enough after battle damage to cue all these radars).
That's basically the tradeoffs. Independant radar systems like CIWS and SeaRAM allow you redundancy from your main radar, but your density is limited due to search radars interfering with each other. Sensorless point defense allow you greater density, but you're wholly reliant on your main radar and combat system tracking and controlling during the engagemet (although since RAM is a heatseeking fire and forget missile, the radar just needs to cue it for the initial launch and then it's off to the races).
"..CIWS placement..if you place them too close, their search radars will interfere with each other."
DeleteThis is something that I have wondered about, and frankly don't completely understand.
As I do understand it (maybe), the semi-active homing of the Block 1 ESSM requires an illuminator like the AN/SPG-62. That illuminates a single target for an individual missile using a narrow X-band signal.
The CIWS, however, is self-contained and uses K-band radar to track and engage.
It does stand to reason, at least from my unknowledgeable standpoint, that the signals could overlap with adjacent CIWS and make the return signals confusing for the tracker.
But shouldn't there be solutions to this? Why hasn't the navy de-conflicted these systems already? Or, maybe they have a solution that I'm just not aware of.
With CIWS, is it possible to narrow the projecting K-band beam to focus more closely on the tracked target and not bleed into an adjacent/overlapping engagement area? Or is K-band, by its very nature, a broader beam that defies narrowing?
Is it possible to use slightly different frequencies within K-band so that adjacent CIWS can be programmed with radar frequencies different enough to differentiate each system's return signal? Or will that change in frequency degrade the needed acuity to track and engage a fast-moving inbound missile/projectile?
Is it possible to use other frequencies?
Goalkeeper apparently uses I-band to search and a combination of I-band and K-band to engage. Is that helpful in de-conflicting CIWS engagements?
Is it reasonable to use a different tracker/illuminator on CIWS that utilizes a narrow band like the X-band used by the AN/SPG-62 system? Would this eliminate the K-band overlap issue when using multiple CIWS?
Has the navy figured all of this out already?
Lutefisk
"Has the navy figured all of this out already?"
DeleteYes. Their brilliant solution is to just put one CIWS on each ship or none, in the case of Zumwalt.
Their brilliant solution is to just put one CIWS on each ship or none..."
DeleteCertainly the path of least resistance.
Lutefisk
"search radars will interfere with each other."
DeleteWhat is your reference or background for this? I've never heard that and I'm dubious. When I think of all the other examples of identical radars placed near each other and still fully functional, it makes me doubt this but I don't know for sure. For example, the SPG-62 guidance radars are placed, almost literally, on top of each other.
For the sake of discussion, let's say you're absolutely correct and only one CIWS (or perhaps two) can be placed on a ship. That would be telling us that we have the wrong weapon system. We either need something completely different or we need to modify how we provide fire control For example, using a single ship's radar to provide fire control for a dozen close weapon systems would be foolish. Take out the single radar and the entire ship's close defense is lost. A viable alternative is to scatter several fire control radars around the ship, each controlling one or two weapons and able to cross connect (for battle damage resiliency).
The SPG-62 guidance radars dont have so much of an issue with interference because they aren't search radars - these are very focused beams for guiding missiles, the search is being done by the main ship radar (Aegis, AMDR, EASR).
DeleteThe problem with CIWS is the dome houses a search radar. It neeeds to be capable of independantly searching for targets on its own. So you have two search radars in close proximity with their "wide" beams - thats the interference issue. To illustrate, it's the difference between flood and spotlight.
CIWS, SPY-1/SPY6, SPG-62, they're all on different bands and are deconflicted from each other; the problem is that multiple CIWS are on the same band.
This is why, in the immediate term, I favor the 21-cell RAM launcher as the point defense of choice for the DDGs. Yes, the system is purely passive and has no independant sensors, but that's mitigated by RAM being a heatseeker that also homes on radar emissions. 21 cells fore and aft allows you to better deal with multiple leakers - a gun can only really attack one target at a time.
Delete"SPG-62 guidance radars"
DeleteThey're literally feet apart! Do you have an actual evidence to support what you say?
Guys, not all radars are the same. What other anon is talking about is SEARCH radars interfering with each other, not DIRECTOR radars.
DeleteSearch radars are using wide beams to, you know, search. They're scanning and looking around. So the issue is that if they're too close to each other, their beams will interfere. The CIWS dome has both a search radar to independantly sweep for targets, and a track radar to engage.
Meanwhile, director radars (SPG-62) aren't doing wide search sweeps. These radars are using focused beams that are pointing at specific targets, AND the Aegis combat system is controlling the directors to point at different targets so that the fire control beams don't interfere with one another.
That said, I would disagree with first anon that the interference is a matter of distance; it's more that it's a matter of placement. Note the Ticos, where the amidship Phalanx are next to each other, separated by some 40 feet of ship. They arent interfering with each other because these two mounts are looking broadside - you turn both of these babies on, and their search radars are going to be sending beams to the broadside. Neither of their SEARCH radars are going to be mutually interfering because neither of them are looking in the same direction.
So it stands to reason that on a DDG-sized ship, it should be possible to have at least 4 CIWS mounts: fordeck in front of the bridge, after deck atop the helo hangar, and amidships facing broadside.
Bigger reason the USN has just two point defense mounts is complacency. USN attitude was always that the fighters would kill the enemy SAG before they could get missiles off, and if any leakers came, it was only one or two missiles. And that was true up to 15 years ago.
DeleteSince 2010, China has been building up its sensor-shooter network in order to generate as large a missile salvo as possible. The Chinese are now able to match the USN in generating missile salvos, with a higher incidence of leakers past the horizon.
ESSM Block 2 is going to an active radar seeker so that it can be fired past the horizon to independantly seek and intercept, and so that you can fire more missiles at a horizon-range defensive effort. 12 guidance channels for SARH interceptor SAMs at the horizon no longer cuts it in 2025.
I'm trying to pull together all the things that are being talked about here in a way that would de-conflict ship missile defense generally, and CIWS specifically.
DeleteIf our ship is in a posture in which it is emitting, we could have the ship's radar system perform incoming missile/drone search and feed that information, as necessary, into the various defense systems; ECM, Standard, ESSM, RAM, SeaRAM, Goalkeeper, Phalanx.
Those systems could then energize their narrow-beam targeting radars and engage targets as appropriate.
If the ship's search radar is lost or degraded, the individual systems' search radars could then be activated.
Is it possible to limit the search arc for these systems, like Phalanx for example, to limit the amount of overlap that they experience?
If the ship is in a non-emitting posture, then both the ship and the individual systems could utilize their EO/IR search capabilities and also passively identify incoming signals from threats.
When threats are identified, each system can energize their targeting radars and engage as appropriate.
This deconfliction does not seem to be a technically insurmountable problem.
In fact, it would seem that if your ship is allowing each system to actively search, the more systems there are the better it should work. If there are a number of systems, then each search radar's fan should be able to be more narrow and thus reach farther out before substantially interfering with its neighbors search fan.
Am I going in the right direction with this?
Lutefisk
The deconfliction issue is really with multiple CIWS search radars mutually interfering with each other, because they're on the same band. Every other system - SPY, SPG-62, etc - is all on separate bands, so even if you turn them all on, they won't have deconfliction issues.
DeleteThe problem isn't deconflicting the separate systems, it's deconflicting multiple CIWS/SeaRAM mounts with their own search radars.
"If our ship is in a posture in which it is emitting, we could have the ship's radar system perform incoming missile/drone search and feed that information, as necessary, into the various defense systems; ECM, Standard, ESSM, RAM, SeaRAM, Goalkeeper, Phalanx."
I feel that if we're doing this, then we might as well just use the 21-cell RAM launcher instead.
Interestingly, I'm told that it's actually possible for AESA radars to do both search AND fire control at the same time; the SPY-6 AMDR and EASR radars have that capability. However, the USN is choosing to stick to dedicated director radars (SPG-62) for the foreseable future, for a certain degree of redundancy, I suppose.
The USS Long Beach (CGN-9) had two Phalanxes close together. Did they conflict with each other?
Deletehttps://en.wikipedia.org/wiki/USS_Long_Beach_(CGN-9)#/media/File:USS_Long_Beach_(CGN-9)_stbd_beam_view.jpg
"The problem isn't deconflicting the separate systems, it's deconflicting multiple CIWS/SeaRAM mounts with their own search radars."
DeleteI wonder how often a ship would be in the position where it would need all the CIWS/SeaRAM mounts performing active search simultaneously?
If controlled by an adequate CIC, I would think that the ship could utilize passive systems to scan for incoming threats and then switch over to central radar systems, when necessary, to allocate targets to individual CIWS mounts. It could have non-conflicting CIWS performing their own target searches.
When the central system can't do it, then it would transfer to decentralized control...and conflicting search radars could become an issue.
Lutefisk
"The USS Long Beach (CGN-9) had two Phalanxes close together. Did they conflict with each other?"
DeleteIf they're looking in the same area, yes, because their beams are sweeping the same region of space and causing mutual interference. You can get around this by making sure that they are looking in separate sectors, which is what they did on the Ticos and Spruances: one mount looks broadside port, the other looks broadside starboard.
It also helps that one of the other mounts is literally an entire deck higher (which, as you'll note, is one of the measures employed with SPG-62 placement to mitigate director radars mutually interfering with each other).
"I wonder how often a ship would be in the position where it would need all the CIWS/SeaRAM mounts performing active search simultaneously?"
DeleteI could see this potentially happening with the older Flight I Burkes, which due to hardware limitations couldn't perform AAW and BMD simultaneously; these were the first DDGs to get SeaRAM so that they'd have an independant self defense capability while Aegis was looking skyward.
Also, while logically missiles are going to be coming in a straight line, programmable waypoints mean that it's possible for the enemy to get a fix close enough to our position for them to send missiles on a circuitous route. In the worst case scenario, we're going to be facing a multi-axis attack from seaskimmers on multiple vectors, high altitude supersonic and hypersonic diving missiles, and high angle antiship ballistic missiles.
"The USS Long Beach (CGN-9) had two Phalanxes close together. Did they conflict with each other?"
DeleteCorrect. The Long Beach had two CIWS separated by around 20 ft with no intervening structure between them. One presumes that they did not interfere with each other.
"I wonder how often a ship would be in the position where it would need all the CIWS/SeaRAM mounts performing active search simultaneously?"
DeleteAlways! Whenever the ship is in combat, every available CIWS would be fully and independently functioning. You may want to review how CIWS works. It uses two separate radars (search and track) and uses the radar to bring the target and the outgoing rounds together.
I believe this entire question of mutually interfering radars is incorrect in any practical sense. The claim was made with zero supporting evidence.
"If they're looking in the same area, yes,"
DeleteThere is not a shred of evidence that mutual interference is an issue on a practical basis. The Long Beach amply demonstrates this. Do you really think if multiple attacks were inbound from one side that only one of the CIWS would be allowed to "look" at it and defend?
Offer some proof that this is a valid concern or cease making the claim.
Just a reminder everyone: the two CIWS mounts on Long Beach are superfiring, as are the SPG-62 mounts on the Burkes and Ticos. I'd say that would do a fair bit to help.
DeleteHaving said that, you're still going to have problems with point defense density depending on your weapon. RAM has backblast issues, so you need a lot more space to site it compared to something like Phalanx.
"superfiring"
DeleteHeight means nothing in this case. It's purely straight line separation which looks to be around twenty feet or so for the Long Beach. NOTHING yet presented supports a claim of interference. Further, on a practical basis, if the twenty foot separation is adequate then CIWS units can be packed as densely as other considerations and factors allow. In other words, if 20 ft is okay then having a few to several CIWS per side is perfectly fine.
Get me some actual proof or stop making the claim.
There is historical precedent for this problem - it's mostly a fire control issue, the MR-123 family of radar originally specced had limited ability to operate with other radars on the same sector.
DeleteHOWEVER this is also a problem that the Chinese solved in 1988. 40 years ago. The main radar they use for the AK-630 has TWS and can track aupnto 64 targets.
It's actually a little funny that Long Beach was mentioned, because these were the early implementations of Phalanx, before people were aware of interference issues. Early Phalanx setups lacked awareness of interference possibilities; later setups see them more widely seperated. It's also primarily an issue with simultaneous operation, which is why setups with CIWS on different axes are mostly fine. It's discussed in this paper:
Deletehttps://secwww.jhuapl.edu/techdigest/content/techdigest/pdf/V18-N03/18-03-Rzerou.pdf
I'll quote a relevant portion below:
"The ship used during the Arabian Gulf tests has two
Phalanx mounts installed midship, facing port and
starboard. During the at-sea tests, the number of false
detections rose significantly when both mounts were
radiating. However, on one occasion the seas were very
smooth, almost like glass, and under these conditions,
no false alarms were seen. Data collected on this phe-
nomenon were analyzed and revealed that the clutter
returns were being modulated slightly by interference
pulses from the other Phalanx mount. The amount of
modulation, probably caused by nonlinear responses in
the front-end electronics of the radar receiver, was
enough to cause the coherent processor to output false
detections (Fig. 11). Key to false-alarm generation was
the synchronous nature of the interference. Interfer-
ence pulses from one radar would line up in time at just
the right intervals to produce significant outputs from
the receiver processor. As a result of this analysis, APL
proposed a minor change in the waveform pulse rep-
etition intervals.4 Although minor from an implemen-
tation point of view, the change unsynchronized the
pulse repetition intervals between the two mounts
without significantly affecting the detection perfor-
mance of the search radar. Once unsynchronized, the
interference pulses will not generate detections in the
radar processor. The proposed modification has been
successfully tested aboard other active Navy ships.
After some additional tests the modification will be
installed in the Fleet."
While this test ship is unmentioned, the position of Phalanx mounts is consistent with that of the Ticonderoga-class cruisers. As an aside, the Spruance-class DDs could probably qualify for as the American ships with the heaviest point defense fit of the last 30 years: they had one Phalanx atop the bridge, one Phalanx atop the helo hangar, Sea Sparrow launcher behind the flight deck, and some ships had the 21-cell RAM on the fantail.
Everything you just cited seems to clearly demonstrate that interference is no longer a problem. Current separation of weapons - to the extent that any ship in any navy even has more than one mounted! - seems much more a matter of fire zone coverage (port/starboard, bow stern) than any interference issue.
DeleteAs best I can tell, we solved mutual interference issues long ago.
I'm just adding some further context, since OP and the other participants in this tangent haven't quite had the full picture with the problems with CIWS.
DeleteI actually think the Chinese are onto something with their developmental efforts into point defense lasers, and their implementation of the LY-1 laser sidesteps the fire control interference issues that were discovered with Phalanx. The main radar cues the laser, then the mount's own EO/IR system locks the target and takes over for fire control. Since EO/IR is completely passive, there's no radar interference to mitigate. You also don't have to worry about missile backblast like RAM, which implies that with sufficient power and cooling, you could make a fairly dense point defense laser cluster.
ComNavOps may want to post this for comments.
ReplyDeleteExecutive Order To Go Back To Steam Catapults On New Aircraft Carriers Coming: Trump
https://www.twz.com/sea/executive-order-to-go-back-to-steam-catapults-on-new-aircraft-carriers-coming-trump
Lots of procedural problems here. Setting aside the question of whether returning to steam is a good idea, I'm not sure that the President can effectively make such an order, dictating the actual design, engineering, and equipping of a naval vessel. He's certainly not qualified in terms of engineering expertise. In addition, it is Congress that, ultimately, dictates what is purchased (or not) via the purse string. Trump issues many EOs, some are implemented and some are not feasible or of questionable legality. Finally, replacement of the existing EMALS will never happen due to the cost. A reversion to steam could happen in future carriers, not yet designed or built.
DeleteHave you done a comparative analysis of steam versus EMALS? I know you've talked about issues with EMALS related to electromagnetic emissions and having to spin down all of the catapults at once for maintenance. If they're not ultimately better, I would think other navies (in particular the Chinese) wouldn't be adopting them.
DeleteI've seen an opinion that the Chinese pursued EM cats over steam because from their perspective, they were starting from scratch with both systems, as they didn't have America's institutional knowledge with steam cats. Potentially they may also have been able to take advantage of their industry experience with electrical propulsion, such as with their maglev trains.
Delete" If they're not ultimately better, I would think other navies (in particular the Chinese) wouldn't be adopting them."
DeleteCome on, now. You know that group think and follow the leader mentality is very much alive and well. Abandoning armor was a foolish path and yet everyone has done it. Battleships were a dead end (to an extent!) and yet everyone kept right on building them. One-at-a-time mine hunting is useless in combat and yet everyone is doing it. Unmanned is useless in combat and yet everyone has jumped on the bandwagon. And so on. The Chinese have adopted EMALS purely because the US has done so. The Chinese take follow the leader to the extreme. Their equipment is a virtual duplicate of ours in most areas.
I've read the Chinese use supercapacitors rather than troublesome flywheels. These weren't available when the Ford class was designed although I read somewhere our Navy wanted to spend billions of dollars to use them to replace the flywheels. Info about this program remains top secret.
ReplyDeleteThe Chinese ones use capacitors because they are direct current and the American ones use alternating current. The decision to use alternating current seems to be the issue for the US. China chose the simpler(which is probably better)
Delete"China chose the simpler(which is probably better)"
DeleteI am not an electrical engineer so I can't offer a definitive opinion, however, basic logic suggests that the issue is nowhere near as simple as you present. If it were that simple and obvious, the US would have gone that route. That implies that both approaches have advantages and disadvantages. It would be wonderful if you researched the advantages and disadvantages of each approach and presented a summary.
I know this is off-topic, but this article about considering the Mk 48 torpedo for surface ships should be of interest. https://www.twz.com/cold-war-u-s-navy-nearly-armed-its-frigates-with-mk-48-heavyweight-torpedoes
ReplyDelete