Your Nations Warships, MKII

[Lyras]

Hexagonal array. Six arms, each about half a nostradamus arm, give or take. Arguably worth fleshing out more in the write up. But the proof of concept is shown here, the details are another point.

[Yukonastan]

Hexagonal array. Six arms, each about half a nostradamus arm, give or take. Arguably worth fleshing out more in the write up. But the proof of concept is shown here, the details are another point.

So you still have 288 antennas split into two sets of 144 receivers and 144 transmitters?

That's still 48 antennas per arm, and considering each arm of the Nostradamus array is 350 metres long, then 350 metres is your diameter at its longest (half the arm length), 304 metres at its shortest (as it's a hexagon).

The beam of the longsword is only 208 metres.

[Triplebaconation]

So six arms, each around 200 meters long, 208 meter beam.

They'll hang about 60 meters off each side of the ship and take a full third of the centerline length.

[Yukonastan]

So six arms, each around 200 meters long, 208 meter beam.

They'll hang about 60 meters off each side of the ship and take a full third of the centerline length.

Only a quarter of the length, Longsword is slightly >= 1200 metres at the waterline.

[Lyras]

So six arms, each around 200 meters long, 208 meter beam.

They'll hang about 60 meters off each side of the ship and take a full third of the centerline length.

50-odd meters beyond the edge of the main hull over the waterline sounds about right. Supporting structures for the array =/= ship structural elements. If this was the gripe, then I can start to see some of your collective uncertainties. Perhaps I haven't been as clear as I thought I had been, and the write up includes less of my notes than I'd remembered.
I dislike typing on my phone.

[Yukonastan]

So six arms, each around 200 meters long, 208 meter beam.

They'll hang about 60 meters off each side of the ship and take a full third of the centerline length.

50-odd meters beyond the edge of the main hull over the waterline sounds about right. Supporting structures for the array =/= ship structural elements. If this was the gripe, then I can start to see some of your collective uncertainties. Perhaps I haven't been as clear as I thought I had been, and the write up includes less of my notes than I'd remembered.
I dislike typing on my phone.

Fifty metres of overhang to the widest point, assuming two of the six arms are parallel with the keel axis, seventy-five metres assuming that two arms are tangent to the keel axis.

Still makes the ship a third wider. Not sure if I'd want to buy it, though. Not sure if I even CAN buy it, considering I play my nation as if it's forty years ago.

[Triplebaconation]

Seriously?

Leaving aside the facts that the elements need a grounded plane around them, the scaling properties of log-periodic radars like Nostradamus inevitably meaning less range, ship motion (spectral noise and the problem of converting slant range into ground range, especially now that elements are 150 meters off the centerline), noise from the other massive radars (where are they???), and so forth and so on, a radar that size just looks silly.

[Lyras]

None of the above issues cannot be solved or mitigated. Will take some electronic work, but eminently do-able. As is the underlying point. Whether or not it looks silly worries me far less.

[Yukonastan]

None of the above issues cannot be solved or mitigated. Will take some electronic work, but eminently do-able. As is the underlying point. Whether or not it looks silly worries me far less.

While we're on the Longsword, what year is it in? What year, canonically, was it designed?

[Lyras]

None of the above issues cannot be solved or mitigated. Will take some electronic work, but eminently do-able. As is the underlying point. Whether or not it looks silly worries me far less.

While we're on the Longsword, what year is it in? What year, canonically, was it designed?

Late MT. Whenever I first posted the damn thing.

[Yukonastan]

While we're on the Longsword, what year is it in? What year, canonically, was it designed?

Late MT. Whenever I first posted the damn thing.

Soo... 1974 would definitely be out, I guess, considering you posted it almost five years ago.

I still fail to see why you would need OTH radar on a ship, or why the ship would need to be so fuckhuge. It's nothing but an AShM magnet that way.
And yes, it comes up fairly often over on the realism thread, "How do we disable or destroy fuckhuge warships such as the Longsword?"

[Mostrov]

(Image)

The question I have is whether it would simply be more worthwhile to have it on a platform instead of a ship. It would be ideally suited to it.

[Yukonastan]

(Image)

The question I have is whether it would simply be more worthwhile to have it on a platform instead of a ship. It would be ideally suited to it.

Largest oil platform at this time is 133m by 100m. This array is about 304m to 350m on a side.

[Triplebaconation]

None of the above issues cannot be solved or mitigated. Will take some electronic work, but eminently do-able. As is the underlying point. Whether or not it looks silly worries me far less.

The problem with this revised configuration is that antenna gain and angular resolution are largely dependent on receiver aperture diameter.* That's why Nostradamus at 384m has a 2000km range, while JORN at 3.4km can probably manage 4000km. The gain problem can theoretically be solved with incredibly advanced electronics, but the resolution is limited by immutable physical laws of the universe.

The revised Longsword radar has an aperture diameter of ~200m and a range of 7200km. That's less believable now than when everybody assumed the array ran down the length of the ship somehow.

*) Skywave radar equation:


There was some confusion about the importance of area earlier. Keep in mind that "area" in the basic radar equation means RCS of the target. Also keep in mind that most diagrams showing OTH radar operation are highly exaggerated. The radar is actually aimed at the horizon, not at the high angle shown in diagrams. Returns arrive the same way, so a circular array on the ground doesn't necessarily mean a bigger useful antenna. The real advantage of a circular array is that it allows 360 degree coverage. It also comes with some disadvantages - in a Nostradamus-type layout the receiver isn't in the far field and efficiency suffers.

[Lyras]

Yuko, main advantage is detecting and tracking opposing fleets and/or aircraft from well outside their engagement envelope, so that you can hit them, while they cant hit you. Very simplistically put. TBN, that is an answer I'll try to get to other than from my phone.

[Yukonastan]

Yuko, main advantage is detecting and tracking opposing fleets and/or aircraft from well outside their engagement envelope, so that you can hit them, while they cant hit you. Very simplistically put. TBN, that is an answer I'll try to get to other than from my phone.

Your radar's range ends up being vastly less than the 7000 km claimed. Granted, LRASM's range is under a thousand kilometres, but your skywave array will be near maximum range to detect them.

[Lyras]

Yuko, main advantage is detecting and tracking opposing fleets and/or aircraft from well outside their engagement envelope, so that you can hit them, while they cant hit you. Very simplistically put. TBN, that is an answer I'll try to get to other than from my phone.

Your radar's range ends up being vastly less than the 7000 km claimed. Granted, LRASM's range is under a thousand kilometres, but your skywave array will be near maximum range to detect them.

I obviously disagree with the shorter range assertion. Were it so, then you would be correct, and the ship would serve no purpose. But I only have my phone atm, and wont get into those points now, as you can appreciate.
But the long-range track is the theory.

[Crookfur]

(Image)

i actually really like this good job.

[New Vihenia]

None of the above issues cannot be solved or mitigated. Will take some electronic work, but eminently do-able. As is the underlying point. Whether or not it looks silly worries me far less.

Hmm any EMC (Electromagnetic compatibility) Considerations ? Like say... preventing the spurious lobes from the radar from disrupting electronics or radiating personnel ?

[San-Silvacian]

if they get cancer its their fault.

[Oaledonia]

Late MT. Whenever I first posted the damn thing.

Soo... 1974 would definitely be out, I guess, considering you posted it almost five years ago.

I still fail to see why you would need OTH radar on a ship, or why the ship would need to be so fuckhuge. It's nothing but an AShM magnet that way.
And yes, it comes up fairly often over on the realism thread, "How do we disable or destroy fuckhuge warships such as the Longsword?"

How would you buy one and not be mocked for the money you spent on it is the real question.

[Allanea]

The real problem of Longsword is that if your RADAR can detect me at 7,000 km, then I can detect your RADAR at least at 7,000 km, about in the same way a man using a flashlight in a dark and stormy night in an open field can be visible.

At which point, I can target it at much further than the engagement envelope of most anti-ship missiles.


The engagement envelope of AShMs is primarily not limited by the aerial capability of a missile to fly X miles, it's limited by the ability of ships to detect each other... you see where this is going.

[Connori Pilgrims]

The real problem of Longsword is that if your RADAR can detect me at 7,000 km, then I can detect your RADAR at least at 7,000 km, about in the same way a man using a flashlight in a dark and stormy night in an open field can be visible.

At which point, I can target it at much further than the engagement envelope of most anti-ship missiles.


The engagement envelope of AShMs is primarily not limited by the aerial capability of a missile to fly X miles, it's limited by the ability of ships to detect each other... you see where this is going.

Your first point that such a powerful radar even if indeed truly feasible and practicable would basically be a "hey I'm here everybody" sign had merit... but then you had to basically say that present-day Harpoons and other AShMs can actually reach over 1000km, in which case I have to and again.

Real life ships can already attack other ships well beyond the range of their own organic sensors thanks to scout helicopters/AEW&C/UAVs/satellites. What restricts ranges are simple physical dimensions; a given size missile can only carry enough fuel to fly X range at Y speed. Another restriction is accuracy problems; even if you can fly a missile that far the missile will likely find nothing as the target will have been long gone, unless you have mid-course datalinks (which can be disrupted) or fly so fast that the missile can get within reasonable distance to use its active sensors.

A 7000km AShM will either have to be a ballistic missile or a large cruise missile which automatically restricts which platforms can carry a meaningful number of them to be tactically useful.

[San-Silvacian]

He means that AShM commonly aren't used at their max range.

but hey we can also read into a post way to much too

yeah alleana why the fuck do you think i can launch my harpun 100000000km thats silly u baddie

[The New Lowlands]

The real problem of Longsword is that if your RADAR can detect me at 7,000 km, then I can detect your RADAR at least at 7,000 km, about in the same way a man using a flashlight in a dark and stormy night in an open field can be visible.

At which point, I can target it at much further than the engagement envelope of most anti-ship missiles.


The engagement envelope of AShMs is primarily not limited by the aerial capability of a missile to fly X miles, it's limited by the ability of ships to detect each other... you see where this is going.

Your first point that such a powerful radar even if indeed truly feasible and practicable would basically be a "hey I'm here everybody" sign had merit... but then you had to basically say that present-day Harpoons and other AShMs can actually reach over 1000km, in which case I have to and again.

Real life ships can already attack other ships well beyond the range of their own organic sensors thanks to scout helicopters/AEW&C/UAVs/satellites. What restricts ranges are simple physical dimensions; a given size missile can only carry enough fuel to fly X range at Y speed. Another restriction is accuracy problems; even if you can fly a missile that far the missile will likely find nothing as the target will have been long gone, unless you have mid-course datalinks (which can be disrupted) or fly so fast that the missile can get within reasonable distance to use its active sensors.

A 7000km AShM will either have to be a ballistic missile or a large cruise missile which automatically restricts which platforms can carry a meaningful number of them to be tactically useful.

Longsword costs 1,2000 Bn$

Minuteman III costs circa 7 Mn$? And would be able to hit it from anywhere so long as somethings tracking it, I think.

So... I don't really see the problem?