NationStates Jolt Archive

Phalanx-class Air Area Defense Destroyer (DDH-101)
Displacement: 6,300 tonnes
Length = 141.2 m
Beam = 16.5 m
Draft = 5.1 m
Propulsion: 2 shafts, 1 five-bladed propeller per shaft
Powerplant: 2 diesel-electric turbines
Speed: 27 knots
Range: 4,000 km
Crew: 240 (25 officers, 215 enlisted)
Armaments:
1 36-cell Mk 41 VLS (quad-loaded ESSMs, standard loadout),
3 Goalkeeper CIWS
2 21-cell Sea-RAM launcher carrying RIM-116 Rolling Airframe Missiles
1 76 mm 38-calibre OTO-Brada cannon
2 12.5 mm machine guns
Sensors/Combat Systems:
Mk 4 Hawkeye Sea/Air Search Radar (750 km ID range for ships, 350 km ID range for aircraft, 360 degree coverage horizontal)
Mk 2 Passive Radar (50 km ID range)
Passive Sonar
"Tactician Series II" Intermediate Fire Control System
"Spectre" ECM Suite
GPS/Galileo Navigation/Tracking system, Map and Compass backup
Aircraft: 1 light or medium helicopter
Construction Time: 3 months
Cost: US$345,000,000
Maintenance: US$2,250,000 / year

Notes: The Battle of the Trivalvian Sea on May 23, 2009 demonstrated the poor capacity of existing Trivalvian ships against an aerial and missile strike. The Trivalvian Department of National Defense decided to tackle the problem on two fronts: long-range research into improving the performance of existing CIWS and anti-air weapon systems and development of a dedicated air defense platform that could be assigned to escort capital ships.

The "Phalanx" was the first vessel to be designed to answer the second need. It's primary function is to target and destroy incoming enemy missiles and aircraft, with only minor capacity to engage surface targets and no capacity to engage enemy submarines. The three CIWS mounts - more than even the "Guardian"-class cruiser, are keyed into the fire control system to not only defend the ship, but also to target and destroy missiles attacking the vessel that the Phalanx is escorting at the time; although this also require the Phalanx-class destroyer to remain relatively close to a vessel it is escorting. Improvements to the Tactician FCS have allowed it to better identify and priortize threats for the CIWS mounts to engage.

The actual weapons themselves are off-the-shelf technology. The Naval Weapons Research Program is currently working on improved CIWS and missile systems to fit the mounts of the Phalanx. Depending on progress in this area, a "Phalanx Flight II" design may be deployed as early as 2015.

[OOC: Love the concept, love the design, love the fact that it was my missiles 'wot made it get made'.]

That's a pretty high block coefficient, more on par with a battleship (this ship's, so far as I can figure, is around 0.615; most battleships are in the area of 0.6) than an escort. You'll want a cB of 0.3 to 0.4—this (http://z4.invisionfree.com/NSDraftroom/index.php?showtopic=326) will tell you how to refine your ship's hull design. Other than that, it looks all right. If I might make a suggestion for an addition, however: since you're using ETC, which is mostly considered a PMT technology (I know—we have it now, but anyway), you might also want to consider whether or not you want to put a HELLADS-type system on this.

Funny you should mention that: I used the Canadian Iroquois destroyer as a reference and Rosdivian's method for figuring out stats. (Figures retrieved off of Wikipedia, it was not mentioned whether the stated length was waterline or overall, but there seemed to be some contention on whether waterline was needed for a proper block coefficient calculation).

I never found any reference to the HELLADs system in my previous searches (and I do travel to the Draftroom from time to time). Links? Be aware that Trivalvian tech level is usually in the 2010 to 2020 range, although I also draw from a few unique technologies (a result of my reading New Scientist on a regular basis).

http://en.wikipedia.org/wiki/HELLADS

^ Since you're in that sort of tech range, this should have been begun to be implemented.

Figures for length and beam on Wikipedia, unless otherwise stated, are overall. And yeah, you need to have the waterline length, or else the cB (submerged:volume ratio) is the volume. If your beam is shorter at the waterline, as well, you might want to use the waterline beam to get a more accurate measurement.

Thanks - I'll probably consider it for the Phalanx Flight III and for newer battleships and cruisers.

As for displacement and other figures; I've not been able to find a proper waterline length for the Iroquois destroyer - and pictures don't suggest much difference between the waterline and overall length, maybe 5 meters tops? But Wikipedia has some figures wrong, and that does adjust the block coefficient slightly (.528 vs my earlier calculation of .536).

Stupid question time: if I understand the concept correctly, block coefficient helps to account for the more streamlined shape of the ship's hull, which otherwise makes calculating volume a real pain. So the closer the cB is to 1, the closer the ship is to being essentially a floating box. Smaller cBs might indicate a more streamlined hull and hence maybe a faster ship (all other things being equal).

With that said, does it truly matter what the cB is for a destroyer?

Better to have a single forty-cell (5 bank) Mk. 41 VLS (tactical or strike variant - you decide) similar to the RL De Zeven Provincien (http://www.naval-technology.com/projects/dezeven/)-class rather than 2 18-cell VLS. You could definitely fit a larger gun on the ship as well, say 76mm and avoiding the ETC if necessary.

Thanks for the suggestions, Isselmere - I'll make the changes to the weapons right away. Any thoughts on the rest of the design, and on the question of block coefficient and its usefulness? I'm interested in anything that improves the design process :D

If your spec's are correct, could I perhaps pixel this? This ship is really cool, and I want to see it laid out. Do you mind?

Theoroshia, that would be wonderful! Go right ahead, but keep in mind the changes I'm making to the weapons thanks to Isselmere's wonderful suggestions.

As Isselmere has already stated the ship is a little undergunned. Even with an enlarge VLS (Mk 41s come in multiples of eight and are typically paired, you usually see 8, 16, 32, 48, or 64, though you could field your VLS easily) your ship is vulnerable to saturation attacks. For example my County class destroyers typically carry 25 anti-ship missiles and can salvo fire them all quickly, plus they fight in packs. That's a lot to intercept and there plenty of more dangerous foes out there then me.

:DGranted, no defense is perfect, and I'm well aware there are people who can outgun anything, anywhere, anytime. Fair enough; my nation's (comparatively) new to the international scene and while it's looking to make waves, it's not going to be diving into major wars headfirst.

That said... with a 7,000 ton (metric, in case there's confusion) full displacement, perhaps an extra one or two CIWS mounts could be employed. Perhaps a second 11-cell Sea-RAM mount and a third Goalkeeper?

As for the Type 41 VLS, I might have it as a 36 or 42-cell unit (partly because, since we're Trivalvians, we like things in multiples of three :D )

:DGranted, no defense is perfect, and I'm well aware there are people who can outgun anything, anywhere, anytime. Fair enough; my nation's (comparatively) new to the international scene and while it's looking to make waves, it's not going to be diving into major wars headfirst.

That said... with a 7,000 ton (metric, in case there's confusion) full displacement, perhaps an extra one or two CIWS mounts could be employed. Perhaps a second 11-cell Sea-RAM mount and a third Goalkeeper?

As for the Type 41 VLS, I might have it as a 36 or 42-cell unit (partly because, since we're Trivalvians, we like things in multiples of three :D )

I think the Type 45 is a good blueprint for what you're going for. I'd go with a 48 cell VLS, a 127mm gun, two or three CIWS systems, and maybe some torpedo tubes.

Another thing to consider is the ESSM (Evolved Sea Sparrow Missile), you can "quad pack" four of them into a single VLS cell and increase you load out considerably. They're shorter ranged than a SM-2, but numbers do count for something.

By "Type 45" I assume you're referring to the real-life British Type 45 air defense destroyer. Good thinking, although if I understand this correctly, the Phalanx will have a slightly different purpose than most air-defense destroyers (though feel free to correct me on this).

You see, the Phalanx will not only be a deterrent against enemy aircraft, but is designed to "get between" other ships in the fleet and any missiles headed their way. So, the Phalanx (or two or three of them) would sit near a battleship and intercept any anti-shipping missiles headed their way, thus reducing the number of missiles the battleship's own CIWS systems will have to contend with. (Of course, this also means an enemy will have to expend anti-shipping missiles to sink the Phalanx destroyers, which are that many missiles *not* directed at the ship or ships the Phalanx's are escorting).

So I'll probably go ahead with 5 CIWS systems (2 Sea-RAMs with RIM-118 Rolling Airframe Missiles and 3 Goalkeeper CIWS mounts). A 36-cell Mk 41 VLS (with quad-loading ESSMs that would give me 144 ESSMs to use against enemy aircraft). I like the idea of the 127 mm cannon (thanks!) but no torpedo tubes - the Phalanx has to concentrate as much attention on dealing with aircraft and missiles. Anti-ship and anti-submarine warfare I'll leave to other ship types in the fleet.

Specs updated in first post.

Hi

I don't think there is such thing as a RIM-118 missile. I think you want the RIM-116 Rolling Airframe Missile. The missiles are pretty small, and come in batteries of 21.

Since it is an air defense destroyer, I recommend the the Oto Breda 76 mm for use as its main gun. With its rate of fire (up to 120 rounds per minute), it is suitable for use as an AA gun or CIWS.

Yup, it's the 116 not the 118 - I got my info wrong. I'll correct that. Thanks!

Final Specs:

Phalanx-class Air Area Defense Destroyer (DDH-101)
Displacement: 6,300 tonnes
Length = 141.2 m
Beam = 16.5 m
Draft = 5.1 m
Propulsion: 2 shafts, 1 five-bladed propeller per shaft
Powerplant: 2 diesel-electric turbines
Speed: 27 knots
Range: 4,000 km
Crew: 240 (25 officers, 215 enlisted)
Armaments:
1 36-cell Mk 41 VLS (quad-loaded ESSMs, standard loadout),
8 Goalkeeper CIWS
6 21-cell Sea-RAM launcher carrying RIM-116 Rolling Airframe Missiles
1 76 mm 38-calibre OTO-Brada cannon
2 12.5 mm machine guns
Sensors/Combat Systems:
Mk 4 Hawkeye Sea/Air Search Radar (750 km ID range for ships, 350 km ID range for aircraft, 360 degree coverage horizontal)
Mk 2 Passive Radar (50 km ID range)
Passive Sonar
"Tactician Series III" Intermediate Fire Control System
"Spectre" ECM Suite
GPS/Galileo Navigation/Tracking system, Map and Compass backup
Aircraft: 1 light or medium helicopter
Construction Time: 4 months
Cost: US$445,000,000
Maintenance: US$2,750,000 / year

Theoroshia: if you want to pixel this, go ahead; let me know when it's ready :)

Thanks - I'll probably consider it for the Phalanx Flight III and for newer battleships and cruisers.

As for displacement and other figures; I've not been able to find a proper waterline length for the Iroquois destroyer - and pictures don't suggest much difference between the waterline and overall length, maybe 5 meters tops? But Wikipedia has some figures wrong, and that does adjust the block coefficient slightly (.528 vs my earlier calculation of .536).

Stupid question time: if I understand the concept correctly, block coefficient helps to account for the more streamlined shape of the ship's hull, which otherwise makes calculating volume a real pain. So the closer the cB is to 1, the closer the ship is to being essentially a floating box. Smaller cBs might indicate a more streamlined hull and hence maybe a faster ship (all other things being equal).

With that said, does it truly matter what the cB is for a destroyer?

Imagine a ship as a box. A rectangular one, really. You find the volume of this rectangle, say its 1,000 (its 10 metres long, 10 metres wide, and 10 metres deep). That means the rectangle weighs 1,000 tons. Of course this rectangle is actually a ship; lets say it has a block coefficient of .250, that means that only .250 of the rectangle's volume is actually the ship, which means that it actually only weighs 250 tons. Assuming a battleship such as ... say, Yamato, is a box:

Her volume is such: 256 (length) x 36.9 (width) x 11 (draught) = 103,910.4. We use waterline dimensions for this. If you made a box with the dimensions of the Battleship Yamato its volume would be 103,910.4 tons; which is also what it'd displace. Now you just account for *how much* of the box is actually presented by the ship; you do this by taking the maximum displacement of the ship (72,800 tons) and dividing it by the volume of the dimensions (103,910 tons) - it is precisely .700. Thats your block coefficient: how much of the box - formed by the dimensions of the ship - is used to determine displacement amongst other things.

However, Yamato was very slow for these two reasons: a high cB meant that she was very "full" and needs more power to wave ratio to move through the water, and her engines couldn't supply that. Secondly she had a high beam (so as to reduce draught, that was a strategic design concept) which also mean tshe was fatter and fuller than normal. Her length/beam ratio is (you use overall for this) , 263 / 38.7, which is 6.7. Thats pretty low compared to contemporary battleships.

Lets look at Iowa.

Her dimensions/volume are as follows: 262 x 32.9 x 11.3 = 97,403.74. Now, Iowa's real max displacement was a meagre 58,000 tons compared to Yamato's 72,800! Her cB is .595, and her length to beam ratio is 8.2 She is a much thinner hull form in all respects; she managed an extra six knots (minimum!) faster than Yamato. However, these come at a price, namely:

1. Less weight means less damage can be absorbed.
2. Less weight means less weapons (3 x III 16" compared to 3 x III 46.1cm)
3. Less weight means less armour (12in compared to 18in, 7.1 compared to 7.8 inches, etc)

So, IMO, it needs to be a balance. For destroyers, you dont need armour or HGs, so you weight is significantly lower, and ergo your cB can be lower, allowing for higher speeds. If you go too low you lose stability and seakeeping though.

Thank you, Questers! At least someone got around to explaining that in detail, finally!

Given the number of weapons now onboard the Phalanx, I'll probably keep it's current cB, but I'll drop the speed down a couple of knots. And that should be that! Time to put this baby in the water and see how well she floats!