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Notional 9000tFL USN FFG with THE POWER OF THE ATOM
http://67.205.157.234/forums/viewtopic.php?f=15&t=6369		 Page 10 of 14
Author:  erik_t [ July 4th, 2016, 10:57 pm ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
The Fourth of July seemed like a good day to redraw everything from scratch, having internalized a lot of detailed frustration at legacy decisions made earlier in the drawing.

It's not really all that different, just a clean-sheet that incorporates a lot of things I'd pondered. Overall, the previous drawing seemed overloaded once I started building a front view. Like.... way overloaded. AESAs are heavy. On the drawing side of things, perhaps the most visually notable change is that I've gone to a Zumwalt-like set of rapidly extensible/retractable railings on the helo deck, based on what I understand to be the solution used on DDG-1000. This allows us to eliminate the obnoxious gallery half-deck solution I'd previously employed. Beartrap accommodation is now a faired extrusion above the flight deck, which is better in every way.

Other notable design changes:
  • After deep thought, I have abandoned the MEADS-based L-band family. 18' AMDR-S SPY+20dB is pretty much awesome. We have L-band air search radar based on the 'dorito' V-22 AEW concept, which also serves as IFF. These arrays are much less grunty than the giant L-band units envisioned previously, but are probably capable enough to force adversaries to consider L-band LO in their planning.
  • The SQS-60 MF sonar is gone. In its place, we have a humongous conformal LF set. To hell with STEALTH BATTLESHIP ATTACKS UNDER COVER OF DAYLIGHT. LF is the way, the truth, and the life in serious blue-water ASW. If we're in brownwater environs, that's why we have 1) helos 2) an ability to deploy 11m daughter craft. SQS-61 remains, because to hell with Kingfisher.
  • The primary diesel gensets are gone. We now ship two RR4500 SSGTGs, for a total of about 10MW electrical. These are underneath the forward SHF satcom dome. I envision that restarting a fusion plant might require a lot of surplus power (enforcing lots of powerful EM fields, things of that nature), so a gutsier backup plant is desirable. Four Cat C18 emergency generators provide 550kWe each, two forward and two aft. I have in my notes that these are the emergency generators used on Zumwalt... I can't source that, though.
  • We've abandoned Mk 57 PVLS in favor of cold eject launch systems like Northrup-Grumman has been pimping. This gives us the equivalent of 96 Mk 57 cells, or 120 Mk 41 cells, or 72 36" (!!!!) cells, or some combination thereof.
  • Tonnage, too, is basically that of Zumwalt. We've traded one big gun for more VLS, better radar, and more helo facilities. If anything, I think this hull is still a bit overloaded.
  • Built-in daughter craft remain as 11m RIB aft and 7m abandon-ship boat in the port superstructure. We still fit a max of four AW101 equivalent helos, or four MH-60 and 4-6 TEUs, etc etc.
  • Other armament and sensors remain unchanged. 90 reloadable XM501L cells, 3x2 50mm Bushmaster, a several-hundred-KW solid-state laser, 8' AMDR-X aloft with 2' arrays aft for 360deg casualty coverage, MX-10MS (four, now) for EO/IR duties...
I must admit I am even more fond of the new redraw.

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Author:  heuhen [ July 5th, 2016, 12:04 am ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
I am getting a Kirov...
Author:  r3mu511 [ July 5th, 2016, 5:13 am ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
erik_t wrote:
After deep thought, I have abandoned the MEADS-based L-band family. 18' AMDR-S SPY+20dB is pretty much awesome.
fwiw, IRL raytheon's AMDR-S 18-foot array (ie. composed of 69 RMA/radar-modular-assemblies) actually gives an approx +25 dB improvement over spy-1 (ie. an approx 316x sensitivity improvement)...

also IRL, the raytheon radar suite controller will run the AMDR arrays using a +/- 45 degree azimuth steering, hence each face only covers 90 degrees (this is in contrast to the notional LRDR/long-range-discrimination-radar used on the HHI LPD-based BMD designs w/c use +/- 60 degree azimuth steering arrays to give 120 degrees coverage per face)...

azimuth steering range affects not just the software control of the individual radiating element phase variations, but also affects the actual physical spacing between elements, ie. +/- 60 degree steering (ie. 120 degrees per face) requires spacing b/w elements of not wider than ~0.54 times the wavelength to avoid grating sidelobes, and using a square grid distribution (eg. assuming 10cm s-band wavelength, spacing b/w elements will be approx 5.4 cm)...

a requirement for just +/- 45 degree steering (ie. 90 degree coverage per face) will allow a wider spacing b/w elements of ~0.59 times the wavelength hence allowing for fewer elements to achieve the narrower azimuth steering required, meaning less cost, lighter array weight, and lower array density for an individual array face (eg. assuming 10cm s-band, approx 5.9 cm spacing b/w elements)...

so if you're using the real world raytheon amdr array you might shift back to 90 degree coverage per face... then again this is for a AU/fictional setting so might just be moot anyway, hehe...
Author:  erik_t [ July 5th, 2016, 7:08 pm ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
Fascinating. I knew qualitatively that there would be implications for array element spacing and programming, but no specifics.

Right now I don't see a reasonable way to move to a four-array configuration on this hull, but it's something I'll keep in mind in the future.
Author:  erik_t [ July 8th, 2016, 1:51 am ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
As usual, satcom breaks and then fixes and then breaks again and then re-fixes everything.

I was doing some evening reading on some interesting mid-2000s work by Syntonics at Ohio State, with a mind to improving the satcom disposition. Basically, using flat-panel but non-phased-array antennas, they were doing interesting concentric-antenna work that had the upshot of allowing for large lightweight antennas for multiple bands within a relatively small dome.

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Long story short, we can claim WSC-6(V)5 SHF performance forward and aft, with similarly excellent UHF and EHF performance, and fit a pair of slightly handicapped SHF+EHF ~3' antennas amidships for backup and/or casualty use. These would be more than enough to take down an EAM from EHF or slow data via SHF, while the OE-538's provide backup UHF transceive capability.

I'm sure these are higher RCS than the previous units, but whatever. We want to be reduced visibility, not STEALTH BATTLESHIP ATTACKS UNDER COVER OF DAYLIGHT.

The backup units really are just gravy, I'd be more than happy to have a pair of large units and nothing else. Other minor fiddling has occurred, mostly with VHF+UHF comms, really not worth discussing in text. Note the casualty APG-81 units are at +-45deg to the bow, which means we've got better spares commonality with 81-derived AMDR-X per discussion above, but we have gaps in our X-band illumination from the stern deckhouse. Whatever, I say. We probably have a few active-ESSM aboard for casualty use, and if we can't illuminate against a few targets after we lose the entire front half of the ship... again, whatever.

link to full-size ship drawing
Author:  citizen lambda [ July 9th, 2016, 6:44 pm ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
Very interesting, that nested-doll satcom... Make me wonder 1) what happened to this project in the last 10 years, and 2) if you can do the same thing with phased radar arrays without running into critical weight and power issues.
Anyway, the design is looking good, definitely more balanced on that hull. But, at the risk of being annoying, I have to say it inches closer and closer to a bona fide cruiser...
Author:  r3mu511 [ July 10th, 2016, 6:01 am ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
^combo radar antennas is something that appears doable (at least in back-to-back mounting configuration) as there are examples such as back-to-back same frequency phased arrays: eg. UK Sampson, back-to-back same freq planar arrays: eg. US spq9b, back-to-back mixed freq non-phased arrays: eg. UK type-967/968 L/S-band, Israeli elm-2228-S/X dual-band...

as w/ the case of the mixed-band concentric satcom antennas, if a given antenna face needs to be used at a certain azimuth & elevation, the other antenna faces have to be rotated out of the way... so similarly for radar antennas, either the other antennas faces need to be rotated out of the way, or as in back-to-back mounting the antenna faces are already positioned w/ respect to each other so as not to block each others apperture scanning angles, and the entire assembly is rotated to give all antennas a full hemispherical coverage...

I could imagine a tri-band (L/S/X) system consisting of 3 antenna faces fixed w/ respect to each other at 120 deg angles, and the entire system rotating so as to provide long range/inclement weather/low angle search (L-band), mid-range high angle search (S-band), and horizon search and fine resolution track-while-scan fire control (X-band)... or maybe a compromise dual-face S-/X-band array combo like the dual-band elm-2228s/x example cited above but this time using a dual axis scanning phased array for the x-band antenna...

one concern I can see w/ a mixed band rotating assembly of multiple antenna faces is that the rotation rate may not be optimum for each band's intended use: ie. 60 rpm may be desirable for x-band fire control and horizon search, but would thus limit the dwell time of the L- or S-band search antenna (maybe to mitigate this shorter dwell time, higher effective radiated power for the search antenna might be used to allow more energy to be xmitted at each beam position during the short dwell time)...
Author:  erik_t [ July 10th, 2016, 8:26 pm ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
...which, ultimately, leads us right back to SPS-01.
Quote:
Anyway, the design is looking good, definitely more balanced on that hull. But, at the risk of being annoying, I have to say it inches closer and closer to a bona fide cruiser...
Definitely, although no name has ever described a static and unchanging type over the years. To me, in the 2010s (or even 1990s), it's got no flag facilities so therefore it's not a cruiser. Anyway, I find the prospect of the 14,500 ton destroyer somewhat less offensive than the 6000 ton frigate :) (pay no attention to the thread title)
Author:  citizen lambda [ July 10th, 2016, 8:45 pm ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
Sure, back-to-back aerials work, no trouble there. I haven't spent 3 months drawing 80s Soviet DDGs without learning that. :) This mostly helps in refresh rate and frequency redundancy.
The concept described above by Erik was light, planar composite-backed aerials, arranged on the same vertical axis, each one being transparent to the one below, with a potential for independent rotation. My concern re. radar application is twofold: 1) can you even feed enough power (let alone signal) through the triple rotating base while ensuring transparency, and 2) is there a risk of harmonic interference between arrays, or pure noise jamming from the proximity between the feeds. If this can be solved, I can't see the asynchronous rotation being the blocking point. As long as the arrays are transparent and the mechanics independent but concentric, you can rotate each plate to the desired rpm without trouble.
Anyway, enough OT speculation unless the OP has more first-hand data, but I'll make sure to check out the Brit and Israeli models you mention, might make interesting references.
Quote:
Definitely, although no name has ever described a static and unchanging type over the years. To me, in the 2010s (or even 1990s), it's got no flag facilities so therefore it's not a cruiser. Anyway, I find the prospect of the 14,500 ton destroyer somewhat less offensive than the 6000 ton frigate :) (pay no attention to the thread title)
1) What are your 6 TEU in addition to a whole half-squadron of Seahawks, if not for temporary pre-fab flag facilities (not like you're short on comms anyway)?
2)Aren't 6000t frigates kind of this decade's fashion already? OTOH 15kt destroyer (or even cruisers) are kind of rare these days.
But let's just not re-(re-re-...)start a debate on the names of the various capital classes. No flag facilities => no cruiser. Point taken, but you see how easily you can slip from one to the other.
Author:  erik_t [ July 11th, 2016, 2:01 am ]
Post subject:  Re: Notional 9000tFL USN FFG with THE POWER OF THE ATOM
citizen lambda wrote:
1) What are your 6 TEU in addition to a whole half-squadron of Seahawks, if not for temporary pre-fab flag facilities (not like you're short on comms anyway)?
2)Aren't 6000t frigates kind of this decade's fashion already? OTOH 15kt destroyer (or even cruisers) are kind of rare these days.
But let's just not re-(re-re-...)start a debate on the names of the various capital classes. No flag facilities => no cruiser. Point taken, but you see how easily you can slip from one to the other.
Speaking sensibly and in real terms, the ship's mission is to be a fast task force escort, protecting more valuable ships and swatting away threats. She is capable of independent operation, as much as any modern combatant (and much more so than many historic cruisers) but that is not the intended operational tasking, and certainly there is no scouting role or anything of that nature. In that sense, the destroyer designation makes very much more sense than that of a cruiser, the latter really not existing in Western fleets after WW2. I think you could make a case that there has not been any postwar cruiser, Kirovs and such being their own beast (and I really prefer just calling them RKRs rather than forcing a battleship/battlecruiser narrative).

Not that names really matter to anybody but the parliamentary body who is in charge of funding the unit and ensuring the national dick can swing as far as possible!
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