055 DDG Large Destroyer Thread

ougoah said:

Do we know any specifics of Type 346/A/B?

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Very little actually. The original assessment in the 2000s leaned on it being a C-band AESA radar.
A few years ago a Wikipedia article emerged, claiming that it's a dual S-band/C-band radar with over 5000 T/R elements, with about 25W peak power per S-band transmitter.

Measurements done by some people on SDF/CDF lead to the conclusion that the outer radar panel area is significantly larger than that of the SPY-1 (roughly 4x4m octagon).
My own measurements of the radar superstructure opening for the Type 055 fitting out in Dalian showed 5.1x4.8 meters.

There are some photos of the Type 346 radar array installed on the Type 052D showing a central circular layout with two horizontal rectangular arrays above and below the circle. Some have conjectured these to be the C-band arrays mentioned in the Wikipedia article. My own assessment is that the likelihood of those being C-band FCR arrays is very low, given the relatively small number of elements that can be placed along the vertical axis.

The numbers from the Wikipedia article are likely false. Assuming 5000 T/R elements as stated above, the Type 346 would have a peak radiation power of 125kW per array. I suspect this may be too low. Perhaps that was the case for the first versions installed on the Type 052Cs. SPY-1D is somewhere in the range of 5-6 MW peak power, but it achieves this only by radiating through a single array at any given point in time.

Follow up on my post #6775.

If we take the Type 346B array to be a 4.5m radius circle (larger still than the upcoming SPY-6), with an operating wavelength of 3200 MHz (within SPY-1 spectrum) and a T/R element spacing of 0.536 wavelengths (a common design choice minimizing sidelobe gratings), 6596 elements would be required to populate the array.

Max Demian said:

Very little actually. The original assessment in the 2000s leaned on it being a C-band AESA radar.
A few years ago a Wikipedia article emerged, claiming that it's a dual S-band/C-band radar with over 5000 T/R elements, with about 25W peak power per S-band transmitter.

Measurements done by some people on SDF/CDF lead to the conclusion that the outer radar panel area is significantly larger than that of the SPY-1 (roughly 4x4m octagon).
My own measurements of the radar superstructure opening for the Type 055 fitting out in Dalian showed 5.1x4.8 meters.

There are some photos of the Type 346 radar array installed on the Type 052D showing a central circular layout with two horizontal rectangular arrays above and below the circle. Some have conjectured these to be the C-band arrays mentioned in the Wikipedia article. My own assessment is that the likelihood of those being C-band FCR arrays is very low, given the relatively small number of elements that can be placed along the vertical axis.

The numbers from the Wikipedia article are likely false. Assuming 5000 T/R elements as stated above, the Type 346 would have a peak radiation power of 125kW per array. I suspect this may be too low. Perhaps that was the case for the first versions installed on the Type 052Cs. SPY-1D is somewhere in the range of 5-6 MW peak power, but it achieves this only by radiating through a single array at any given point in time.

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I don't know a thing about AESA technicalities. With the assumed wiki data, the 125KW peak per array is compared to the SPY1D's 5-6MW peak? Do these output figures correspond directly with number of T/R elements?

ougoah said:

I don't know a thing about AESA technicalities. With the assumed wiki data, the 125KW peak per array is compared to the SPY1D's 5-6MW peak? Do these output figures correspond directly with number of T/R elements?

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It gets complicated. AESA radars don't need nearly as high peak powers as PESA radars to achieve the same SNR on target, because they have more efficient receivers. Also the peak power quoted for SPY-1 is not the actual radiated power ... Nonetheless, solid state amplifiers cannot produce anywhere near the peak powers that vacuum tubes can. Solid state amplifiers also tend to be quite inefficient. The whole AESA setup manages to convert only 20-25% of input power into radiation, resulting in huge amounts of heat that needs to be extracted from the panels. The Flight III Burke's are getting a whopping 50% boost to their refrigeration capacity to accommodate the new SPY-6.

But viewed in terms of average radiated power, AESAs are quite comparable to PESAs, and nowadays with GaN are clearly ahead. Some numbers I found for the SPY-1D(V) (2004 vintage) state about 77kW average radiated power per array. The more modern TPY-2 AESA radar has an average radiated power of 81kW and peak power of 410kW, with a smaller 9.2m2 array (this was circa 2010). The latter is an X-band radar, allowing for denser packing of transmitters.

Dante80 said:

The design philosophy was not really flawed at all. Remember, the whole idea was to replace the Iowas and provide naval fire support (NSFS) with good accuracy and cost attributes. Then, VAGS was cancelled (replaced with AGS) and eventually LRLAP was also cancelled. The same thing happened with the ERGM and BTERM programs for the Burke. The whole thing simply became too expensive to develop properly, and started to aggressively take funds from other programs, and that is when the USN pulled the plug. As a concept, vertical gun or railgun based NSFS is still very valid, albeit it is now seen as a wanted component for large surface combatants, not as a base for a distinct platform (like arsenal and NSFS ships).

Have in mind that the Zumwalt was not ever designed to replace the Burkes and the Ticos. CG-21 and DD-21 were, and they were cancelled and reworked via the SC21 program as DD(X) and CG(X). By that time, the whole thing was pretty much done for.

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Playing devil's advocate, let's say that the Zumwalt programme actually actually accomplished everything you just listed, and delivered 29 ships to specification and within budget.

It means the US Navy has 29 Zumwalts designed for land attack close to shore. Yet with the spread of cheap precision strike, such missions are impossible for the Zumwalt to conduct in a contested environment.

That is flawed design.

And by building 29 Zumwalts over the programme construction lifespan (10-15 years), that would inevitably have come at the expense of numerous Arleigh Burkes and Ticodenrogas, which have to be retired as they are at the end of their service lives.

That is the Zumwalts replacing Arleigh Burkes.

And if the US Navy wanted to demonstrate future technologies, they could have done this for far less money with a test vessel instead of a full-fledged destroyer programme.

Correction for my post: https://www.sinodefenceforum.com/type-055-ddg-large-destroyer-thread.t6480/page-678#post-551954

It should write 4.5m diameter circle, not radius.

AndrewS said:

It means the US Navy has 29 Zumwalts designed for land attack close to shore. Yet with the spread of cheap precision strike, such missions are impossible for the Zumwalt to conduct in a contested environment.

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Stealthiness(original concept was even cleaner)+LCS+their unmanned assets.
Against softened non-peer enemy, that'd probably have worked...

I was previously puzzled by the reports of the development of VLS launched ballistic missiles, but I think I understand now.

Taiwan has 2 mountain airbases and runways located on its East Coast, which means mountains are in the way of ballistic missiles launched from mainland China. So there is no quick way for China to launch a surprise missile attack against these airbases and shut them down in a few minutes.

But these 2 airbases are designed to shelter and operate the entire Taiwan Air Force fighter jet inventory, because they know how vulnerable their other airbases are to attack. Taiwan has close to 300 fighter jets in total worth $20Billion+

So it's worth having the Chinese Navy putting together a small task force of 4 Type-55 destroyers with a total of 200 ballistic missiles.
North Korea reportedly sold SCUD-C ballstic missiles with a range of 600km for just $3M each, so 200 ship-launched ballistic missiles would probably cost China less than $1Billion, which is far less than the $20Billion+ of Taiwanese fighter jets presumably inside those mountain airbases.

Then the Type-55 could be stationed say 500 km off the Eastern coastline of Taiwan, which should be far away enough to avoid E-2 AWACs detection and anti-ship missiles launched from Taiwan.

The Type-55 would be able to launch their ballistic missiles against those 2 mountain airbases, and the short time to impact would mean the vast majority of fighter jets would not be able to exit the mountain and scramble into the air before missiles started hitting the runways.

It would also force Taiwan to buy and build yet another PAVE PAWS radar for ballistic missile early warning facing EAST into the Pacific Ocean.
The existing one faces the opposite direction, towards mainland China.

The last PAVE PAWS cost $1.4Billion, and remember that Taiwan only has a military budget of $11Billion per year.

Comments?

Easier and cheaper to just use cruise missiles.

Ship based, VLS launched ballistic missiles would be the AShBM variety, and would exponentially increase Chinese AShBM range, and by extension Chinese A2AD coverage.

Putting AShBMs on 055 cruises and 052D DDGs, it would be the safest way to make those missiles mobile without risking inadvertently starting a full nuclear exchange as could easily happen if China used is SSBNs to launch those AShBMs.

Not only would a sub launched AShBM risk trigging a ‘responding’ enemy nuclear launch on detection, enemy attempts to hunt down such AShBM carrying SSBNs could easily result in nuclear armed SSBMs getting targeted, thereby presenting China with a ‘use them or loose them’ dilemma.