055 DDG Large Destroyer Thread

[Blitzo]

Oh well, now it's a toss-up between you and POP3. You, or you dad, says 10k tonnes and POP3 says 12k tonnes; hard to tell who to believe.

To be fair a ship referred to as sitting in the 10k ton class can easily have a standard displacement much larger.

Ship displacements are not always commonly reported by different people using the same metric of empty/standard/full displacements. His father could simply have referred to it by its empty displacement which makes sense because a 12000 ton standard displacement would logically be about 10k ton empty.

The 128 VLS part is nice, pop3 didn't mention VLS number so I hope that is true

 

[jobjed]

oops... what i meant to say was more than 10k ton

That makes much more sense. Give my thanks to your dad for his service to the nation.

 

[yuxiaochen]

I wish the 128 VLS is true, but since i got this information a year ago, i cannot assure that it will be the exact number they are planning to install now.

 

[no_name]

he did tell me it will a 10k ton "heavy cruiser" type DDG with 2 VLS systems containing a total of 128 missile launchers.

Do you mean two VLS placment positions as in one forward and one towards the back of the ship, or two different types of VLS like a hot and a cold one? I think you mean the former?

 

[nameless]

That is unfortunately a limitation of the CCL system. If you want hot launch, you have to accept a reduced cell width (or diameter?) and if you want cold launch you have to accept a reduced cell length. I believe the internal width of a Mark 41 cell is 0.65m, of which Tomahawk the largest type round takes up the entire space of the cell, leaving you 0.1m on each side for exhaust venting if the PLAN wants a similarly-sized internal cell for its own purposes. I don't know if that is enough or whether a hot-launched missile would have to make due with a smaller internal cell volume. If the cell is circular you could probably get away with corner-only venting but then this configuration precludes quad-packing. Whatever the case, it is readily apparent that a wide variety of cell types would have to have been developed to support the various missile systems that are potentially being used.


That would give it an even larger footprint on/in the ship than is already apparent from the photos, in which case the CCL system would be extremely volume-inefficient compared to a hot launch system.

Your logic makes no sense. Where is your hot launched s300 or HQ-9 for comparison? According to your logic bigger missiles are more inefficient than smaller missiles because they take up more space. Not to mention the fact that hot launch requires a rocket booster as well as increased length of piping, if anything cold launchers are shorter.

 

[SinoSoldier]

I've been following this thread for quite a while now, there were a few things I wanted to say ever since I joined this forum but couldn't due to the sensitive of the information. but when I saw what people are posting on this thread I can finally get it off my chest.

Last summer I went back to china to visit my father, who worked as a naval engineer for the PLAN for the past 2 decades or so, told me there are two new types of DDG are being developed. one of which is the newly revealed 052D. The other one though he didn't give me the exact designation, he did tell me it will a 10k ton "heavy cruiser" type DDG with 2 VLS systems containing a total of 128 missile launchers.

Now I know some people might say "well you jsut got the information from the internet "... but remember I was too afraid to say anything about it anywhere. and now information regarding type 055 are out, I guess I can speak freely for the moment.

cheers.

Don't get arrested!

 

[Solaris]

I believe the "tubes" are square. I've read that the CCL can use corner venting and obviously only circlulsr tubes lack corners, thus squares. This quad packing doesn't become an issue.
Now, you point out that fitting a larger missile like tomahawk will limit the cell's exhaust volume, yes that is true. However is believe that larger missiles will be cold launcher instead, meaning they can fit missiles as large as the 0.85m cell width.

I mean that a circular tube has 4 available 'free' corners to use for venting exhaust because this round tube has to be nested inside a square frame, but that quad-packed air defense missiles would require a square cell and thus would have to vent all along the edges.

Of course, you mention that cold launch requires the addition of a piston to propel the missile out, however considering even HQ-9 has such a piston only 50cm long, even if we double that and cut out 1m out of the 9m length for the strike length CCL cell, that is still 8m left for missile length, and more importantly such a missile can take up the full 0.85m width/diameter of the cell.
Obviously the piston itself will vary in length considering how heavy the missile being driven is, but the key point is that cold launch allows the CCL VLS to take advantage of it's large cell width to launch missiles which smaller hot launch VLS like Mk-41 or Mk-57 cannot.

I didn't mean to suggest there needs to be some kind of mechanical piston system. I'm simply referring to the need for a greater amount of gas and pressure to eject larger missiles, thus a larger gas tank and thicker cell walls. But the 9m length if true would mitigate the size of the larger tank; on the other hand it represents a significant internal volume increase compared to the Mark 41, so again there is a tradeoff, which goes back to my earlier suggestion that possibly this new VLS setup requires a larger displacement vessel for the same number of cells compared to the Mark 41 or the 054A VLS.

Realizing all this, if we try to imagine a hot launch VLS that can do wha the CCL VLS can so -- namely an 8 cell module that launch missiles up to 0.85m diameter -- the result will be something larger than the current CCL VLS because it would necessitate a massive common exhaust system, therefore it's deck floor print and thus overall volume will be much larger than the CCL VLS.
So ultimately I would argue that a CCL VLS is more space efficient in launching larger missiles because the PLANs CCL VLS is designed for both hot and cold launch with minimal reduction in effective cell volume.

This hypothetical common hot/cold VLS system could simply extend downwards to accommodate new exhaust requirements and approach but perhaps not exceed the 9m of the CCL system. Remember that the longest Mark 41 only tops out at 7.7m high. Its deck footprint would remain smaller than the CCL and its internal depth would only approach that of the CCL system, meaning overall the actual total internal volume could still be less.

Your logic makes no sense. Where is your hot launched s300 or HQ-9 for comparison? According to your logic bigger missiles are more inefficient than smaller missiles because they take up more space. Not to mention the fact that hot launch requires a rocket booster as well as increased length of piping, if anything cold launchers are shorter.

Take care not to conflate your understanding of my logic with my actual logic. If a bigger missile and its launch/venting requirements are satisfied by the same size cell as a smaller missile, then there is no greater inefficiency due to the larger missile. If as totoro suggested a separate gas injection system located elsewhere on the ship is required to launch certain (or all) missiles from the new VLS launcher, then most definitely there is much greater space inefficiency since the Mark 41 does not require such a separate system, and neither for that matter does the 052C's cold launch system, since IIRC its gas injection system is located at the center of each 'cylinder'. As for your claim that cold launchers are shorter, if bltizo's statement about the length of the cold launcher at 9m is true, then you are most certainly not correct here, since the Mark 41's longest (strike) length launcher is just under 7.7m.

 

[Blitzo]

ut the 9m length if true would mitigate the size of the larger tank; on the other hand it represents a significant internal volume increase compared to the Mark 41, so again there is a tradeoff, which goes back to my earlier suggestion that possibly this new VLS setup requires a larger displacement vessel for the same number of cells compared to the Mark 41 or the 054A VLS.

I think the only fair way to compare the volume inefficiency versus the PLAN method versus a pure hot launch method like MK-41 or sylver or 054As VLS is to design it so both VLS types have similar effective cell width, similar cell "length" i.e.: the PLAN VLS would reduce the length of the cells to a minimal degree that would be equal to the Mk-41 while allowing for extra length needed for the cold launch system, e.g. a gas driven piston.

In that sense, I believe the mk-41 will have higher cross sectional deck area, compared to the PLAN VLS which will have smaller deck cross section (due to result of no common VLS) but will be slightly longer (to accommodate the extra length of the cold launch system, but is imagine this would only make the cell length a meter longer at most, compared to the longest Mk-41 cell length)


And I dont imagine there would be a separate cold launch system outside of the VLS that is intrinsic to their design if that is what totoro meant: otherwise that would be a poor use of space if a hot launch CCL missile is used in the VLS cell. More likely the extra length of the VLS is meant to self sufficiently hold a cold launch mechanism like a piston.

This hypothetical common hot/cold VLS system could simply extend downwards to accommodate new exhaust requirements and approach but perhaps not exceed the 9m of the CCL system. Remember that the longest Mark 41 only tops out at 7.7m high. Its deck footprint would remain smaller than the CCL and its internal depth would only approach that of the CCL system, meaning overall the actual total internal volume could still be less.

I was under the impression that venting a larger motor in hot launch required an exhaust with a greater cross section (like increasing the diameter of a pipe to allow more water to flow through it rather than increasing the length of the pipe which doesn't change the exhaust volume per unit time that can escape). I've read that a bigger exhaust was one of the design features of mk-57, with hopes that would allow it to carry larger missiles with larger motors in future.

 

[Preux]

I've been following this thread for quite a while now, there were a few things I wanted to say ever since I joined this forum but couldn't due to the sensitive of the information. but when I saw what people are posting on this thread I can finally get it off my chest.

Last summer I went back to china to visit my father, who worked as a naval engineer for the PLAN for the past 2 decades or so, told me there are two new types of DDG are being developed. one of which is the newly revealed 052D. The other one though he didn't give me the exact designation, he did tell me it will a 10k ton "heavy cruiser" type DDG with 2 VLS systems containing a total of 128 missile launchers.

Now I know some people might say "well you jsut got the information from the internet "... but remember I was too afraid to say anything about it anywhere. and now information regarding type 055 are out, I guess I can speak freely for the moment.

cheers.

跳大婶

Tell me if you want a translation.

 

[nameless]

Take care not to conflate your understanding of my logic with my actual logic. If a bigger missile and its launch/venting requirements are satisfied by the same size cell as a smaller missile, then there is no greater inefficiency due to the larger missile. If as totoro suggested a separate gas injection system located elsewhere on the ship is required to launch certain (or all) missiles from the new VLS launcher, then most definitely there is much greater space inefficiency since the Mark 41 does not require such a separate system, and neither for that matter does the 052C's cold launch system, since IIRC its gas injection system is located at the center of each 'cylinder'. As for your claim that cold launchers are shorter, if bltizo's statement about the length of the cold launcher at 9m is true, then you are most certainly not correct here, since the Mark 41's longest (strike) length launcher is just under 7.7m.

The Mark 41 uses a complex venting system so of course it does not have gas injection. According to you the gas injection is not a part of the system because it is "elsewhere on the ship" but nobody said the injection system is any distance away from the cells so its just baseless conjecture on your part. So your previous claims are flawed and as the missile gets larger it will certainly have different venting requirements.

How exactly do you fit a missile longer than its launcher? Since you seem to think so and claim its more efficient. Magic?