Replacing the Jianghus and sub-chasers?

Gollevainen said:

[qimg]http://upload.wikimedia.org/wikipedia/en/8/83/Small_waterplane_area_twin_hull_swath1_large.jpg[/qimg]

this one from good ol' wikipedia...You can do the comparision yourself to the Type 022...

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Relative to the pictures that showed the 22 hoisted up, and given the size of that ship in the picture, I would say the 22 is quite proportional.

all boats hulls goes underwater, unless they use some magic to fly over the waterline Type22 doesent have submarine shaped hull, why would it otherwise descriped as wavepiercing?? ...or have Wave piercing bows??

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Not when the top of it also goes mostly underwater. The thing is that wave piercing are the pylons that connect the hulls to the main deck.

Have you ever seen the Pontiac commercial that longer and wider is better? A car that has a longer and wider wheelbase generates a better ride. Same with a catamaran over a monohull. A catamaran distributes weight over a much larger area and this reduces pitching and roll movement. This is so fundamental an engineering principle in buildings, ships, aircraft and autos I don't know why you're trying to debunk this.

Here why don't you all take a look at this and tell me what is the proportion of the submerged hull to the overall ship is. Its not any different from the picture of the 22 hoisted up which you can find in the CDF. You can also see that the hull design is also very similar to the 22 and follows the same principle.

In these two pics you can clearly see, that All that resembles SWATH in 022 is the wavepiercing form of the pontoons. As in SWATH, the pontoon should look like submarine, and sureficially Type22 seems to have that form. But in SWATH, those 'subs' needs to be...submarine, totally underwater. Then the thinniest point of the pontoons is on the waterline level...this isent the case with Type22. The small brown porpotion you see beging with the waterline, is simply normal boatshaped catamaran keel. If it would be SWATH, then there should be huge cicular bulge...but there isent one....

Type22 isent a SWATH. period

Have you ever seen the Pontiac commercial that longer and wider is better? A car that has a longer and wider wheelbase generates a better ride. Same with a catamaran over a monohull. A catamaran distributes weight over a much larger area and this reduces pitching and roll movement. This is so fundamental an engineering principle in buildings, ships, aircraft and autos I don't know why you're trying to debunk this.

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cars have little to do with sailing. Catamaran has its keel and its underwater. Even Hydrofoils have their foils partially underwater...and that what is uderwater, determins the seakeeping of the ship. Another is the weigth dispersion. It isent simply by dispearsing it to larger area, but in ships, the more it is in the centraline and under the waterline, the better the solution is. With Catamarans, the most proplem comes from that almoust all weigth, even the heavy porpulsion is atop waterline. Catamrans are stable in good weather and the wind it self doesent affect them as much it migth for convential boats, but in heavy waters the situation is different.

For what it's worth Golly is right that the Type-022 isn't technically a SWARTH, not that that makes him right about other aspects of seaworthiness of wave-piercing cat's. Where Corboto becomes right though is the way the bows work when they hit a wave, they go into/through the wave rather than lifting over it - the bow becomes submerssed and the thin blade-like conector between the cat hulls and the main central (out of water) hull acts like a SWARTH. This effect is partly also because of the clever distribution of boyancy; the forward section of the cat' hulls has little boyancy so it sinks into the wave, whereas the central bull which is usually out of the water has a lot of boyancy so it tries to ride the wave - the hull conectors are caught in the middle hence the SWARTH tendency. At least that's how I understand it. This is similar to the bulbus bows on many large monohulls but on a more extreme way. It's worth noting that few small boats, FACs included, have the bulbus bow of the larger frigates etc.

biggest idea behind SWATH is that the large submerged pontoons will house most of the ships weigths and thus making it able to make smaller size hulls as seaworthy vessels. Type22 isent SWATH, and its limited to all catamarans biggest fault, lack of volume for heavy equipment in the hull. Its simply too much to carry such heavy ordanance, fuel and other elements nessery for offshore combatant. You can strom against me as much as you want on its sea keeping, and eventually I migth bend in that front. But so far you havent come into single fact or solution to solve this other aspect of why catamarans doesent make good ship level combatants.

Um no. Look at the SWATH designs, they don't have much of their weight or mass in those hulls either. I don't know why you go on and making your own definitions.

Also the term covers semi submerged.


"1970 - Mitsui Engineering & Shipbuilding Co., in Tokyo, begins basic research on the "semi-submerged catamaran", or SSC. "

"1973 - The acronym "SWATH" is coined by U. S. Navy technocrats who promote its use, rather than "semi-submerged" ship or catamaran, to distinguish this concept from conventional catamarans. "



Lack of volume can be dealt by increasing the size of the deck. The real problem of super large catamarans is the lack of facilities in the world to berth or porth them. We build ships to fit ports just like software is written to fit certain platforms.

Just an observation, but since no one is proposing a Type-022 style catamaran as their ideal next-gen PLAN corvette/light-frigate/sub-chaser/OPV, isn't this argument something better taken to other threads?


Anyway, here's a contemporary Corvette concept, the Dutch Sigma family. This is the top-end version which as the following vital statistics:

Model: SCHELDE NAVAL PATROL 9113
Length: 90.71 meters
Width: 13.02 meters
Draft: 3.6 meters
Displacement: 1692 ton
Max speed: 28 knots
Cruising speed: 18 knots
Engines: 2 x diesel engines at 8910 kW max power each; twin shaft with passive roll stablisation
Endurance: 300 nm @ cruising speed
Weapons:
Surface to air missile: MBDA Mistral TETRAL
Surface to surface missile: MBDA Excocet MM40 block 2
Main Gun: Oto-Melara 76 mm (A position)
Auxiliary Gun: 2 x 20 mm Vector G12 (B position)
Torpedo: 3A 244S Mode II/MU 90 in 2 x B515 launchers
Sensors
Combat System: Thales TACTICOS
Main search radar: MW08 3D multibeam surveillance radar
Fire control radar: LIROD Mk2 tracking radar
Data Link: LINK Y Mk2 datalink system
Sonar: Thales Kingklip medium frequency active/passive ASW hull mounted sonar
Naval Communications: Thales/Signaal FOKON
Decoy/Chaff Launcher: TERMA SKWS
Integrated Platform Management System: Imtech UniMACs 3000 Integrated Bridge System
Accommodations: 80

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More interesting pics (far to big to put in the post):




Personally I feel that the Sigma corvettes have insufficient air-defences in the Indonesian form. I think that the next-gen PLAN corvette needs to have something in the HQ-7~LY-10 range as minimum, and a proper CIWS for point defence.


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When it comes to helicopters, I think that it needs to be able to handle a Z-9. Here's a useful reference pic which will come in handy trying to devise a layount:

planeman said:

Just an observation, but since no one is proposing a Type-022 style catamaran as their ideal next-gen PLAN corvette/light-frigate/sub-chaser/OPV, isn't this argument something better taken to other threads?

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Well I did propose a trimaran design which indirectly led to this cat debate.

Ok, I've moved to Phase 3 of my concept design phase, where I start drawing my ideas to scale and refining the general arrangement. BUT, I need help because I don't know very much about the insides of a ship, powerplants or sensors.

Here's the current position with the hull mapped out:


I used a Z-9 helicopter as the primary decider for the helipad length, and hanger length/width. To save weight I've gone for a non-telescopic hanger which eats into my internal volume. I've also used the 4m tall Z-9 to dictate the deck height as 2.5m between decks (i.e. hanger is 5m tall = 2 decks).

The blue shaded area beside the hanger is the missile bin. It is 2m wide and 3m deep and over 10m long, allowing 2 x SS-N-22 Moskit SSMs to be stacked vertically in each missile bin. Alturnative missiles that would fit:
2 x YJ-62s SSMs
4/6 x YJ-83s SSMs
4/6 x RPK-9 (SS-N-29) ASW missiles
4/6 x SS-N-27Klub ASW missiles
14+ x TL-10B light-SSMs

The blue shaded box further forward is an 8 cell VLS for PL-12 derived SAMs which would be cold-launched and have a range of approximately 30km. If you count 9 cells, that's because the middle one would be used to house the gas cylinders for the cold launch system. Also, it's way deeper than the 3.85m PL-12 to account for the stealthy single-piece lid above the launch cells.

I think I'll put triple Yu-7 torpedo tubes next to the hanger behind the SSM bins, and a single 4 round QW-4 ("FL-2000") point defence SAM launcher atop the hanger.

On the foredeck I propose to put a modified Type-730 CIWS with stealthy casing and the fire control radar and IRST sensor moved to alturnative (less exposed to waves) locations.

The current dimensions are 95m in length with a 12.4m beam. Taking into account the compariatively slender bow section, I project a full displacement of approximately 1,700t.

PLEASE advise me on the required sensor fit. I was thinking along the lines of having a phased array radar for PL-12 fire control that rotates on top of a stealthy mast - the radar would normally be hidden behind a sloping lid which flips open when it is in use - drastically reducing the radar cross-section of the boat when it is not in use. The main air search radar should also be a phased array(?).

Also, PLEASE, what is the best powerplant arrangement for a boat of this type? I was thinking diesels driving waterjets, with the engines exhausting below the waterline to reduce IR signiture.

1. Thales Sea Tiger air/surface search radar, Racal RM-1290 navigation radar, Type 327G fire control for the CIWS, and for the ASM's, the radar depends on what is installed. For sonars, DUBV-23 (SJD-8/9) hull-mounted sonar, and a towed sonar array as well. All tried and tested systems already in use by the PLAN.

2. For engines, I would go for a simple diesel drive to a variable pitch propeller. The last time someone in a major project tried to use a MTU diesel engine with a waterjet resulted in a problem-plagued design (4 MTU 20V-1163 diesel engines coupled to 4 KaMeWa 112 waterjets in a 1,281 metric tonne ship) that drank fuel, was unreliable, and caused a political scandal for the government in power.