Littoral Combat Ships (LCS)

Discussion in 'World Armed Forces' started by Jeff Head, Oct 14, 2006.

  1. Max Demian
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    Max Demian Junior Member
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    Just because you found some SSPA based on GaN on the open market is no evidence of GaN radars being installed on PLAN ships.

    GaN substrate wafers are not suitable for high power applications needed for military radars. Ideally, you would want something like SiC or even diamond.
     
  2. Tam
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    Tam Senior Member
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    GaN substrates are all about high power applications. GaN does not have the linearity of GaAs, which makes GaAs more suited for low power applications with very precise levels of amplitude control.

    Analyzing technological and industrial capabilities in a country is a solid and established way to estimate that country's defense industry.

    GaN SiC substrates are also being produced in China.

    We have already discussed this in the 055 threat long ago. There was mention that the 055 was equipped with GaN radars by a Beijing based observer, Lie Jie, about the time the 055 was publicly launched. Furthermore, there is the issue of 055's excess level of electrical generation, six generators, each likely a 3.8MW. The third I would add, is that the 055 does not have any need for an AESA metric wave radar like the 052D, which on the newest models have gone a major revision. This means what the 055 has, is more than strong enough to make metric wave radar redundant on that ship.
     
  3. Max Demian
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    Max Demian Junior Member
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    I think we should make a separate thread to discuss the Type 346 radar. That said:

    The reason why GaN is not an ideal substrate for high power is its poor thermal conductivity, slightly worse than that of silicon. That would create engineering challenges in removing the excess heat. SiC has 5 times the conductivity of GaN, and diamond another 5 times over SiC.

    Your observation about the metric radar is a speculation based on the assumption that the 055 is a strict superset of 052D in terms of electronic capabilities. I am not convinced that is warranted. There are plenty of examples where two classes of destroyers complement each other, like the Akizuki and the Kongo/Atago, where the Akizuki provides an ASCM umbrella to the Atago and Kongo.

    However, it cannot be denied that the radar on the 055 is more potent than the one on 052D. My measurements (posted on CDF) gave about 18.1m2 (7000 TRM) for the radar face on the 055 and a max of 16m2 for 052D, which might be a bit too generous. The Wiki article claims it is a 4mx4m octagon which would put it at about 12m2. So somewhere in between.
    Also, the 052D probably has less than half the electrical power at its disposal to channel into radar output and chilling. If you remember, at CDF I made a back of the envelope calculation where I assumed the 052D can channel as much power into its radar as the Burke IIA can (likely too optimistic), and the 055 as much as the Flight III (more confident). That resulted with a power-aperture product of 2.28x in favor of 055 over 052D. All of that assuming GaAs based radars on both classes.

    Finally, you assumption that the each of the six generators is a 3.8MW unit is again pushing it. Based on the photos that we've seen, the aft ventilation openings appear too small to accommodate 3 such generators. Also, my (homebrewed) statistical analysis of power generators onboard non-electric drive currently active destroyers in the 6000t-7500t class (9 classes), gave an average of 1.5MW per generator unit. The majority of the generators had a diesel engine as a primer mover.

    I in light of that, and claims on this board that the generators are diesel units, I would not assume more than 2MW per generator set.
     
  4. Tam
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    Tam Senior Member
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    GaN happens to have less heat than GaAs. Cooling is a challenge but never an insurmountable obstacle, and you do it all the time from gaming to cryptomining PCs to servers and to supercomputers the last which presents the biggest challenge of all.

    Those GaN SSPAs I have shown do not exist in a vacuum and not without a context. If there is a piece, it belongs to something, and those GaN SSPAs definitely belong to something. I am surprised further that that company has an entire catalog of such parts.

    That does not make sense from the PLAN standpoint, why should the 052D have the metric radar and the 055 doesn't. Presumably, early rumored drawings of the 055, fanbased but drawn on what's been rumored and leaked, point to having originally a large long wave radar on the back. And yes, the 055 is a superset of the 052D, and given that the purpose of the 055 is to be an AAW/A2D defense destroyer, having a long or metric wave radar would make sense to resolve against LO threats. The current radars on the 055 would have been powerful enough to make a long or metric wave radar moot and redundant. Plus Its the 054A that does the job of complementing.

    The Akizuki being a destroyer is actually more in this day and age, a frigate, complete with only 32 VLS.

    The Type 052D is a Hu Jin Tao era ship, where Chinese ambitions are rising and reflects the doctrines there in, but the Type 055 is a Xi Jing Ping era ship, where those ambitions are kicked up a notch and so will these doctrines.

    Looking at ventilation opening size doesn't tell you enough about air volume since you also have to factor the speed of the air. As a matter of fact, if ventilation opening is too large, resulting in a large venturi channel, the speed of the air is reduced, and as a result, so will air volume. You really should not presume air volume just from the look of the opening. But I do doubt that is the only opening there is.

    There needs to mention that there is another opening on the side at the funnels, one that is even larger.

    22090118_1410403082329949_4355813239942179622_n1-750x350.jpg

    Which is sometimes closed in other pictures, which points to this being opened only in certain situations, and its not used to feed the main engine, since it is also closed when the ship is doing high speed test trials.

    kv8f0b3e1do11.jpg

    As for the diesel engines, they don't seem to have any problems powering up to 9.7MW. Considering this is CSSC's site.

    http://www.cmpeb.cn/cmpEng/0;prds.cmp.aspx

    There is also a 2.8MW power unit. There is also the 3.8MW unit and up to a 9.7MW unit.

    A Flight III would have four 2.5MW units. Six 2.8MW units would exceed that of a Flight III Burke.

    Another feature that points that the radar on the Type 055 is much more potent --- not just more potent but more significantly so --- is that the IFF arrays on the 055 are much larger and thicker than on the 052D, and not by a small margin. The sizing of the IFF array has grown significantly from the 052C, where its still within the flat panel, to the 052D which is now outside of it, to the 055 which is even larger and much thicker, the backside indicating they are using AESA modules on it.

    There is also the question if these other arrays are also GaN, starting with the four faced X-band AESA set on the top mast, to the octet arrays on top of the bridge. Having GaN on smaller but higher frequency (C and X-band) arrays isn't unusual, given the Asahi class destroyer that's based from the Akizuki, and the German F125 frigate, as well as the single faced rotating TRS-4D that is going on top of LCS 17 and beyond.
     
  5. Max Demian
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    Max Demian Junior Member
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    @Tam

    I did say that I was probably a bit too generous in regards to both the aperture size and input power on the Type 346 aboard the 052D. I think it's quite in the realm of plausible that the power aperture product is 3x+ higher on the Type 055, absent any other improvements. That could explain the larger IFF interrogators.

    I do agree about the 054A frigates complementing the 052Ds. They probably provide a similar ASCM/ASW umbrella like the Akizuki do to the Kongo. To this day, there is no official confirmation that the HHQ-9 can engage sea-skimmers, while the Buks can.

    However, we will have to agree to disagree about the Type 346 onboard the 055 being GaN technology. The SPY-6 won't reach IOC before 2022 and Raytheon has been working on GaN since the early 90s. I haven't even seen them start selling the GaN refresh of the venerable AN/TPY-2 yet. At the same time, of the top 10 companies manufacturing GaN ICs worldwide, none are in China. Yet somehow China is able to manufacture comparable GaN MMICs in quantities that put the combined of US, Japan and Europe to shame. I would put that in the probability category of a blue moon.

    As for the diesel generators, I illustrated how much of an outlier it would be to have units of such capacity. Truth be told, among electric drive ships there are indeed diesel generaror units in the 2.8MW class (FREMM). However, these are largely used for propulsion purposes and replace the diesel engines otherwise found on CODOG vessels.

    Finally, the Burke III will have 3x4MW GT based generators.
     
    #2275 Max Demian, Jun 7, 2019
    Last edited: Jun 7, 2019
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  6. Tam
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    Tam Senior Member
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    HHQ-9 should be able to engage sea skimmers, if they have been using the S-300 as a template. Mid models of the S-300 (48N6E which are the models China received) has a minimum altitude of 10 meters. Even with 20 meters altitude, the HQ-9 with 180kg of warhead can splash a sea skimmer. Note that the Buk with a 70kg warhead has a splash radius of 17 meters, and the HQ-9 would certainly go beyond that. The HQ-9 might even be used against surface targets; 180kg of warhead is as big as a YJ-83 antiship missile's. The Type 054A complement for the larger ships is more likely for ASW, with the 052D covering the 054A for long range AAW.

    Your estimates on the aperture size and input power of the Type 346 is loosely based on too much guess. Limit of power on the SSPA would not only depend on the semiconductor but also on the size of the SSPA. With GaAs it is typically 1.5w per mm. A 1 sqr. cm die would input about 150 watts.

    Note that if you go the 052D thread recently, there is a news video clip that showed the Type 346A in testing and including on the inside or the back of the array. What is inside no longer looks like a QTRM (4 TR per module) as suggested in the wiki article for the 346. The 346A looks like it uses straight TRMs (one TR per module) which greatly increases the power density.

    This is not relevant, since I have already showed you that GaN SSPAs are already available in the Chinese market for radar and radio use. This includes GaN substrates for radar use. These SSPAs do not exist on a zero context; they are clearly part of something larger in the first place. There are S-band, C-band, X-band and K-band. SSPAs being sold through the catalog are most likely aimed for universities, institutes and small defense institutes for use in prototyping. Students learning to make their own T/R modules for example, or those writing research papers.

    I also prefer to rely on Chinese internal sources, as they tend to be remarkably accurate in leak, such as the name of the first 055 long before it was official.

    You tend to forget that these companies making GaN MMICs, they also have plants in China, which they supply to Chinese OEMs or export from those. Much of GaN MMIC production is by far is in lighting; for radars and radio, the production assigned for radar would be incredibly small compared for lighting, of which China has a major national goal to light the country with GaN LED for power conservation. The GaN used for the US military do not rely on any of the top producers but through boutique fabs owned and run by Raytheon and Northrop Grumman. The use of boutique fabs makes per unit very expensive, since each unit has to pay for running the fab, but it gives enormous flexibility and security control. The opacity inherent in studying the Chinese economy also makes it difficult to assess the manufacturers there. Don't put too much faith in studies when they themselves are subject to limitations in access.

    I also pointed out that China mines and refines about 80% of the Gallium in the world. That does however, have a way in controlling and decreasing prices. The high grade Gallium that other countries put out, often rely on the low grade Gallium they import from China.

    SPY-6's IOC is irrelevant. Its IOC date is more the result of the USN's bureaucracy and additional requirements piled on it. You forget that Raytheon has already IOC its AN/MPQ-65 (not sure if I got the label correct) radar, which is GaN, for the Patriot system, to replace the MPQ-53. I believe that was back in 2016 or 2017. Japan has already put in service the Asahi class, which features GaN based C-band and X-band radars, and Germany has already put in service the Cassidian TRS-4D radar on the F125 frigate. The single faced rotating version of the TRS-4D will go into the LCS starting with LCS 17. That's right, LCS will get GaN radars ahead of Flight III Burke. Thales is already offering the APAR Block II, which is GaN. I don't know if SAAB Sea Giraffe for the Independence class would be offering GaN, but the Europe defense defense industry as a whole is fast moving into GaN based AESA as a standard. GaN would also be used for satellite communication, and in civilian use, with base stations. So Huawei could already be deploying 5G base stations using GaN MIMO arrays.

    My understanding is that they use 4 x 2.5MW.

    The fact that the CSSC catalog includes 3.8MW and 9.7MW units --- this is China's largest shipbuilder and one of the biggest producers in the world, they should know shipbuilding --- shows you these are being used. Furthermore, since they are licensed from MAN, these units are also in use for other non China made ships.

    I would find it ridiculous that you would use 6 x 1.8MW if you are able to use 3 x 2.8MW or 2 x 3.8MW. Given the relative size of the generators they are the 2.8MW and/or 3.8MW kind on the Type 055.
     
    #2276 Tam, Jun 7, 2019
    Last edited: Jun 7, 2019
  7. Brumby
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    Your understanding is wrong then. The source of the 3 X 4 MW is from Captain Mark Vandroff, program manager of DDG51.
     
  8. dtulsa
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    dtulsa Junior Member

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    No offense guys while the Chinese and Burke radars and generators stuff is nice and interesting it has little to to do with LCS or FFGX conversation
     
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  9. Jura
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    Jura General

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    about 4m for a Bushmaster, as many as two (2) of them for LCSs:
    Contracts for June 5, 2019 https://dod.defense.gov/News/Contracts/Contract-View/Article/1867634/


    NAVY

    General Dynamics Land Systems (GDLS), Sterling Heights, Michigan, is awarded a $25,568,897 firm-fixed-price contract for the production of the MK 46 MOD 2 Gun Weapon System (GWS) for the Littoral Combat Ship (LCS) and Landing Platform Dock (LPD) programs, along with fiscal 2019 spares requirement. The 30mm MK 46 MOD 2 GWS is a remotely operated system that uses a high velocity cannon for shipboard self-defense against small, high-speed surface targets. This contract is for the procurement of two 30mm MK 46 MOD 2 GWSs for the LCS Surface Warfare Mission module, two 30mm MK 46 MOD 2 GWSs for the LPD-29, two 30mm MK 46 MOD 2 GWSs for the LPD-30, and associated spare parts. Work will be performed in Sterling Heights, Michigan (60 percent); Anniston, Alabama (25 percent); Lima, Ohio (7 percent); Tallahassee, Florida (6 percent); and Scranton, Pennsylvania (2 percent), and is expected to be completed by September 2021. Fiscal 2017, 2018 and 2019 shipbuilding and conversion (Navy); fiscal 2018 and 2019 other procurement (Navy), and fiscal 2019 weapons procurement (Navy) in the amount of $24,568,897 will be obligated at time of award and will not expire at the end of the year. The Naval Sea Systems Command, Washington, District of Columbia, is the contracting activity (N00024-19-C-5388).
     
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  10. Jura
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    Jura General

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    seeking translation from Pentagonese:

    "The SASC included language approving the purchase of a more LCS, “If it is necessary to maintain a full and open competition for the guided missile Frigate (FFG(X)) with a single source award in Fiscal Year 2020,” as stated in the Senate version of FY 2020 NDAA."

    for context, the source is
    House, Senate Defense Bills Tough on Littoral Combat Ship Programs https://news.usni.org/2019/06/13/house-senate-defense-bills-tough-on-littoral-combat-ship-programs

    thank you
     
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