[Post Reply] [*]  Page 3 of 3  [ 27 posts ]  Go to page « 1 2 3
Author Message
erik_t
Post subject: Re: CGN-36 'TyBeach' - final versionPosted: February 17th, 2019, 1:35 pm
Offline
Posts: 2706
Joined: July 26th, 2010, 11:38 pm
Location: Midwest US
I assume so. A phased array serving TVM (which is how Patriot has always worked) ought to scale just fine. The internet says the real-life system can handle nine targets, which sounds to me like a system operator limitation (it's got to fit on a truck! let's do a 3x3 screen layout) more than a technical limitation.

In a shipboard installation, that limitation would obviously be relaxed.


Top
[Profile] [Quote]
Hood
Post subject: Re: CGN-36 'TyBeach' - final versionPosted: February 18th, 2019, 4:14 pm
Offline
Posts: 6103
Joined: July 31st, 2010, 10:07 am
Sounds good to me.

Just thinking outside the box, what impact would this have on AEGIS and in your AU USN, would more older cruisers and destroyers receive this system to boost their fire-control?

_________________
Hood's Worklist
English Electric Canberra FD
Interwar RN Capital Ships
Super-Darings
Never-Were British Aircraft


Top
[Profile] [Quote]
erik_t
Post subject: Re: CGN-36 'TyBeach' - final versionPosted: February 19th, 2019, 2:11 pm
Offline
Posts: 2706
Joined: July 26th, 2010, 11:38 pm
Location: Midwest US
That's a good question, but it's really hard to answer. So much of what we know about the pre-Aegis missile ships came about after Typhon's cancellation -- Belknap didn't commission until a year later, and of course the whole next generation of USN missile destroyers/cruisers was cancelled. That money was instead programmed for the 3-T get-well program, which made the Farraguts and Leahys worth more than a stern frown in the direction of a target.

There's also the eternal question of how army systems will perform in navy service, and vice versa. C-band (which is shared by SPG-59 and MPQ-53) evidently works well enough on land, and it was considered for SPY-1. But it's undeniably a weaker band for search, especially in heavy weather. Would it have been acceptable in service use at sea, with 1980-era computers backing it up? Hard to say. Maybe it would be the case that you could get away with something like a Ticonderoga (with a dedicated lower-frequency air search set) but not a Burke. Or maybe it could just replace SPY-1 basically one-for-one.

But if we consider the question, "what would the USN force structure look like if single escorts could drive off regiment-scale raids in 1965", that opens an even bigger can of worms. Indeed, much of the reason the carriers were removed from the strategic strike role is because of a growing recognition that the escorts could no longer protect the carriers from Soviet naval aviation strikes. Big-deck proponents might successfully defend their role against Polaris, with the latter somewhat de-emphasized.

All that is to say, you might see a Belknap or a Leahy, loaded with Typhon-LR, with a MPQ-53 replacing each set of SPG-55, with a passing resemblance (in system design) to a Slava. If everything worked according to plan, that would offer a much superior escort to what we saw in real life. But that's only scratching the surface of the possibilities.


Last edited by erik_t on February 20th, 2019, 3:18 am, edited 2 times in total.

Top
[Profile] [Quote]
ForceA1
Post subject: Re: CGN-36 'TyBeach' - final versionPosted: February 19th, 2019, 5:20 pm
Offline
Posts: 17
Joined: November 12th, 2017, 5:58 pm
Something like SCB 172A with MPQ-53 would be interesting to see.


Top
[Profile] [Quote]
Hood
Post subject: Re: CGN-36 'TyBeach' - final versionPosted: February 20th, 2019, 12:58 pm
Offline
Posts: 6103
Joined: July 31st, 2010, 10:07 am
Yep, I know it was an open-ended what-if question, but the impacts would have quite large on the fleet structure and as you say, the possibilities are pretty wide.

_________________
Hood's Worklist
English Electric Canberra FD
Interwar RN Capital Ships
Super-Darings
Never-Were British Aircraft


Top
[Profile] [Quote]
Sea Skimmer
Post subject: Re: CGN-36 'TyBeach' - final versionPosted: March 5th, 2019, 6:58 am
Offline
Posts: 4
Joined: December 4th, 2017, 10:29 pm
Ah.... I realllly feel like you did this before in like 2010? But it's still good. Much has changed in the interim on drawing small objects I've noticed.
erik_t wrote: *
I assume so. A phased array serving TVM (which is how Patriot has always worked) ought to scale just fine. The internet says the real-life system can handle nine targets, which sounds to me like a system operator limitation (it's got to fit on a truck! let's do a 3x3 screen layout) more than a technical limitation.

In a shipboard installation, that limitation would obviously be relaxed.
MPQ-53 as originally built could track 50 targets, control 9 missiles at a time against (sources vary) up to nine targets, and control 3 of those missiles in terminal CWI homing mode FYI. Operator limits didn't matter, it was capable of fully automatic modes and based on the video of the monochromatic displays I've seen you were pretty much hitting airliner destroying territory long before you had 50 tracks on screen. It didn't help that the actual firing sector was a V-shape, so whatever form factor your display has, it's just gonna be that Vee that actually matters for data with a 1970s TV screen!

And we still use this!

The big limitation here is just time sharing on the radar, the separate TVM uplink antenna helps with that, but the duty cycle on this radar was like 10% as built, and your dividing that over and over again.

But no such figures have ever been released for the improved mid 1990s era MPQ-65 upgrade of Patriot which added a second traveling wave tube assembly sharing the same phase shifters. The point of which was to allow the ABM and AAW modes at the same time, but obviously ought to have a non trivial impact on other capabilities.

Shipboard you could probably track more targets at some kind of precision, but actually engaging more targets at once would be very hard to brute force. Being a C-band radar you aren't scanning huge areas of sky with each beam you emit. Making the antenna bigger doesn't help with that much at all, scanning for new targets still involves a whole lot of duty cycle and so does tracking existing ones. A more powerful radar can generate more total power and have more effective range, but that doesn't mean out of hand that it can actually engage more targets with PESA. But perhaps a warship could have had two traveling wave tubes from the get go? I mean I'm sure on paper it could!

Worth pointing out that S-300F is the same idea as this, except without the TVM control portion, and it's 1980s form was rated for engaging four targets with two missiles each simultaneously. Terminal homing was purely SARH via the main antenna array.


Top
[Profile] [Quote]
erik_t
Post subject: Re: CGN-36 'TyBeach' - final versionPosted: March 5th, 2019, 2:32 pm
Offline
Posts: 2706
Joined: July 26th, 2010, 11:38 pm
Location: Midwest US
Sea Skimmer wrote: *
Ah.... I realllly feel like you did this before in like 2010? But it's still good. Much has changed in the interim on drawing small objects I've noticed.
I know I drew a series of sort of freehand SCB-227-inspired designs back in the long, long ago, with SPG-59. I don't remember if we ever worked through MPQ-53 refits.
Quote:
MPQ-53 as originally built could track 50 targets, control 9 missiles at a time against (sources vary) up to nine targets, and control 3 of those missiles in terminal CWI homing mode FYI. Operator limits didn't matter, it was capable of fully automatic modes and based on the video of the monochromatic displays I've seen you were pretty much hitting airliner destroying territory long before you had 50 tracks on screen. It didn't help that the actual firing sector was a V-shape, so whatever form factor your display has, it's just gonna be that Vee that actually matters for data with a 1970s TV screen!

And we still use this!

The big limitation here is just time sharing on the radar, the separate TVM uplink antenna helps with that, but the duty cycle on this radar was like 10% as built, and your dividing that over and over again.
My thinking was that it seems like TVM in that era ought to be at least somewhat computationally limited, not just array limited. At least in midcourse (maybe not in terminal), you need to be running launcher-side calculations to tell the missile where to go, but your track accuracy might be sufficient that the radar isn't any more loaded in midcourse (per target) than it is in tracking.
Quote:
Shipboard you could probably track more targets at some kind of precision, but actually engaging more targets at once would be very hard to brute force. Being a C-band radar you aren't scanning huge areas of sky with each beam you emit. Making the antenna bigger doesn't help with that much at all, scanning for new targets still involves a whole lot of duty cycle and so does tracking existing ones. A more powerful radar can generate more total power and have more effective range, but that doesn't mean out of hand that it can actually engage more targets with PESA. But perhaps a warship could have had two traveling wave tubes from the get go? I mean I'm sure on paper it could!
Well, right off the top, we're giving up on MPQ-53 handling long-range search, although it would need to perform some sort of target localization based on the coarse data fed from SPS-49. It seems like this ought to help quite a bit. In a casual, hand-waving sort of sense, C-band sucks for search anyway, and so I'd figure we'd recover more track/engage capability by giving up search than (say) doing the opposite. Whatever time-sharing of the array we're using for long-range search, it's not very efficient use of that time.

Shifting from SPS-49 to SPS-48 ought to give further improvements by this metric, although I'm reluctant to give up L-band on a long-range platform like this.

An alternative path, which I'd definitely considered, is retaining at least one trainable director (the bow, presumably) and duplicate real-life-scale MPQ-53 in that location for enhanced sector capability, i.e., eighteen missiles in the air over something like a 300 degree field of fire.

The maximum approach might be to retain all three trainable directors (replaced with MPQ-53), keep SPS-49 aft, fit SPS-48 forward, and fit only the three fixed MPQ-53 arrays on the main deckhouse. With all arrays operating, this would give 360deg coverage with at least two arrays, and three-array coverage across broad arcs abeam. The result certainly would not be aesthetically graceful, but that's not why we build warships.


Top
[Profile] [Quote]
Display: Sort by: Direction:
[Post Reply]  Page 3 of 3  [ 27 posts ]  Return to “Personal Designs” | Go to page « 1 2 3

Jump to: 

Who is online

Users browsing this forum: No registered users and 3 guests


The team | Delete all board cookies | All times are UTC


cron
Powered by phpBB® Forum Software © phpBB Limited
[ GZIP: Off ]