PLAN Anti-ship/surface missiles

T

Totoro

Major
VIP Professional
We actually don't know the range of either missile. Stuff one reads online is not supported by a clear and trustworthy source. It could be YJ18 range is over 220 km. (Klub is officially advertised with such range) It could also be YJ12 range is 500 km. Certainly, 400+ km range for YJ12 would be very logical and to be expected, even at the cost of a small warhead - as then every launch platform (H6) could self designate the target at said distance.

We don't know if there are changes from Klub to YJ18. Klub antiship missile is officially advertised with 20 km of supersonic dash. That's a bit low for today's threats. But YJ18 may have very well increased that. Still, we don't know.

Having a missile cruise its way over 400 km at more or less constant mach 3 is certainly beneficial (terminal speed in low altitude attack profile, which i believe is more proudent, is likely to be somewhat less, given the low altitude and thick atmosphere. Maybe similar to KH-31's mach 2.5?) The target has less time to react and defend/escape. There's less time to actively threaten the targeting platforms. And given that the flight time over said 400 km example is likely some 8 minutes, there's actually very little the defender can do even by removing the targeting platforms as the missile will most likely still find the target after those 8 minutes - the ship is unlikely to be able to move that much away in those 8 minutes. (maybe 6 or so km) Of course, final radar lock when flying low is likely going to be at some 30 km away from the target ship. So actual time elapsed to that point will be less, some 7.5 minutes to get to the 30 km mark.

Lets assume the same range for YJ18 - 400 km. And lets assume 30 km distance from the ship for the final target check, when the missile keeps a radar lock onto the ship the whole time and flies supersonically. supersonic dash stage is for Klub advertised at 700 m/s. That's just north of mach 2.

Cruise flight speed for Klub is advertised between 180 and 240 m/s. That sounds to me like it's dependent on fuel consumption or missile mass, as fuel is being spent. So I'll just use 210 m/s. That's basically mach 0.64. That's 28 minutes to get to the 30 km mark. That's also quite okay, I'd say. The ship may be some 20-ish km away from its original position but the missiles may be doing a periodic update even from a 100 km away. (this is guesswork, there's no public info on whether missiles are programmed to do that)

But if the targeting platform is engaged after firing either destroyed or simply chased away - and if no more targeting updates are given to the missiles while they're still half way to the target, at some 200 km - then the missiles may not get any more updates until they lock onto something on their own. Which opens to the door to jamming, decoys, various deceptions or even, theoretically, forces the missiles to do last minute turns to change their trajectory, and if that's done at the end of the potential range - the missile could miss altogether.

All in all, I would label YJ-12 to be somewhat more potent platform of the two. But at the same time, it's a bigger missile, double the weight, so it's simply not practical to be carried/used in similar numbers per launch platforms.
 
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caohailiang

Junior Member
Registered Member
Totoro said:
We actually don't know the range of either missile. Stuff one reads online is not supported by a clear and trustworthy source. It could be YJ18 range is over 220 km. (Klub is officially advertised with such range) It could also be YJ12 range is 500 km. Certainly, 400+ km range for YJ12 would be very logical and to be expected, even at the cost of a small warhead - as then every launch platform (H6) could self designate the target at said distance.

We don't know if there are changes from Klub to YJ18. Klub antiship missile is officially advertised with 20 km of supersonic dash. That's a bit low for today's threats. But YJ18 may have very well increased that. Still, we don't know.

Having a missile cruise its way over 400 km at more or less constant mach 3 is certainly beneficial (terminal speed in low altitude attack profile, which i believe is more proudent, is likely to be somewhat less, given the low altitude and thick atmosphere. Maybe similar to KH-31's mach 2.5?) The target has less time to react and defend/escape. There's less time to actively threaten the targeting platforms. And given that the flight time over said 400 km example is likely some 8 minutes, there's actually very little the defender can do even by removing the targeting platforms as the missile will most likely still find the target after those 8 minutes - the ship is unlikely to be able to move that much away in those 8 minutes. (maybe 6 or so km) Of course, final radar lock when flying low is likely going to be at some 30 km away from the target ship. So actual time elapsed to that point will be less, some 7.5 minutes to get to the 30 km mark.

Lets assume the same range for YJ18 - 400 km. And lets assume 30 km distance from the ship for the final target check, when the missile keeps a radar lock onto the ship the whole time and flies supersonically. supersonic dash stage is for Klub advertised at 700 m/s. That's just north of mach 2.

Cruise flight speed for Klub is advertised between 180 and 240 m/s. That sounds to me like it's dependent on fuel consumption or missile mass, as fuel is being spent. So I'll just use 210 m/s. That's basically mach 0.64. That's 28 minutes to get to the 30 km mark. That's also quite okay, I'd say. The ship may be some 20-ish km away from its original position but the missiles may be doing a periodic update even from a 100 km away. (this is guesswork, there's no public info on whether missiles are programmed to do that)

But if the targeting platform is engaged after firing either destroyed or simply chased away - and if no more targeting updates are given to the missiles while they're still half way to the target, at some 200 km - then the missiles may not get any more updates until they lock onto something on their own. Which opens to the door to jamming, decoys, various deceptions or even, theoretically, forces the missiles to do last minute turns to change their trajectory, and if that's done at the end of the potential range - the missile could miss altogether.

All in all, I would label YJ-12 to be somewhat more potent platform of the two. But at the same time, it's a bigger missile, double the weight, so it's simply not practical to be carried/used in similar numbers per launch platforms.
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I thought YJ18 has some 800km range...cannot remember the source but has been my working assumption
 
T

Totoro

Major
VIP Professional
There are no good sources on ranges, period. One might be tempted to use the US DoD report on china's military where ranges ARE estimated (290nm for YJ18A and 250 nm for YJ12) but that's also mostly pure guesswork. The report itself is done using open source data, and there's no indication actual intelligence officers worked on it. Which wouldn't be surprising given that the whole purpose of the report is political - to portray a grave threat to the US for the US congress, so the DoD gets more funding.

I personally don't think YJ18A can have long range. If Russians could have made Klub reach 300 km, up to the limit of the MTCR, they would have. But one can see there is simply not much room for fuel in that missile. And YJ18 seems to be more or less the same. Even assuming somewhat more fuel efficient engine and even assuming slightly different internal structure, allowing for some more fuel - it's unlikely YJ18 is anywhere close to 800 km.
 
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Totoro

Major
VIP Professional
Hard to say. But i'd say it's unlikely, that it's just too big.

The ship launched variant has a visibly longer booster. Total length is some 8.45 to 8.5 meters. (H6 launched variant is 7.6 to 7.7 meter) So length doesn't seem to be an issue initially, nor is 50-55cm body diameter, but overall width of some 1.15 to 1.25 meters (at widest point between two opposing inlets. If wings are folded in that hypothetical variant.) is more than the diagonal distance of each cell can *realistically* hold. As we know, each cell is 0.85 wide, but as we also know from images, a canister holding a missile needs to be inserted in that cell. So walls of the canister take up some width. And then there has to be at least *some* clearance between inner canister walls and the missile itself. So actual useful diagonal space is not 1.2 meters (which would be of 0.85 wide cell) but surely less.

All that makes it a very, very tight fit, but theoretically it might fit (with wings somehow being folded so they don't add more than 2 cm each to the inlet. And also folded in two places, so they fold not only by 90 degrees but more, as their roots would be right in the corners of each cell) But it leaves absolutely no space for any rocket motor exhaust.

We do know YJ18 is hot launched. But HQ9 is cold launched. With no space for exhaust, hot launch is off the table. So cold launch would have to be used. As far as I can tell by looking at S300V missile with gas container cutouts, a pressurized gas container section will add roughly the same diameter as the missile body, if not a bit more, to the length of the missile. So there's enough energy to push the missile out at sufficient velocity.

So when one adds gas container dimensions, roof and wall thickness of the missile container and some minimal clearance I'd say we're looking upward of 60 cm, possibly close to 70 cm. Again, that seems to be just too much to be added to the length of the missile. So now, in addition to overall width, length too might very well be an issue.

I do think, if we ever do see a similar missile launched from UVLS, it won't be this variant, but something based on it and made somewhat smaller. perhaps also being a good base for another air launched variant, one that tactical aircraft and not just H6 could also carry. Shaving off just 10 cm in overall width, shaving off 10 percent in length could mean overall weight could drop by a quarter from current estimate of 2 to 2.5 tons.
 
T

Tam

Brigadier
Registered Member
Totoro said:
We actually don't know the range of either missile. Stuff one reads online is not supported by a clear and trustworthy source. It could be YJ18 range is over 220 km. (Klub is officially advertised with such range) It could also be YJ12 range is 500 km. Certainly, 400+ km range for YJ12 would be very logical and to be expected, even at the cost of a small warhead - as then every launch platform (H6) could self designate the target at said distance.

We don't know if there are changes from Klub to YJ18. Klub antiship missile is officially advertised with 20 km of supersonic dash. That's a bit low for today's threats. But YJ18 may have very well increased that. Still, we don't know.
Click to expand...

I would say about 25km to 35km for both missiles. No, it has nothing to do with the amount of propellant with the missile.

Having a missile cruise its way over 400 km at more or less constant mach 3 is certainly beneficial (terminal speed in low altitude attack profile, which i believe is more proudent, is likely to be somewhat less, given the low altitude and thick atmosphere. Maybe similar to KH-31's mach 2.5?) The target has less time to react and defend/escape. There's less time to actively threaten the targeting platforms. And given that the flight time over said 400 km example is likely some 8 minutes, there's actually very little the defender can do even by removing the targeting platforms as the missile will most likely still find the target after those 8 minutes - the ship is unlikely to be able to move that much away in those 8 minutes. (maybe 6 or so km) Of course, final radar lock when flying low is likely going to be at some 30 km away from the target ship. So actual time elapsed to that point will be less, some 7.5 minutes to get to the 30 km mark.
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I would think about 25km to 35km, which is based on the target's radar horizon. This is where, after subsonic skimming just over the sea surface, the missile pops up right over the Earth's circumference and the seeker now has a direct line of sight with the target for an active radar seeker lock. This is where the missile drops the cruise missile stage, blows the rocket and sprints from Mach 0.6-9 to Mach 3. The higher figure is for taller targets, and the sprint range gets lower as the target's height gets lower.

Lets assume the same range for YJ18 - 400 km. And lets assume 30 km distance from the ship for the final target check, when the missile keeps a radar lock onto the ship the whole time and flies supersonically. supersonic dash stage is for Klub advertised at 700 m/s. That's just north of mach 2.

Cruise flight speed for Klub is advertised between 180 and 240 m/s. That sounds to me like it's dependent on fuel consumption or missile mass, as fuel is being spent. So I'll just use 210 m/s. That's basically mach 0.64. That's 28 minutes to get to the 30 km mark. That's also quite okay, I'd say. The ship may be some 20-ish km away from its original position but the missiles may be doing a periodic update even from a 100 km away. (this is guesswork, there's no public info on whether missiles are programmed to do that)

But if the targeting platform is engaged after firing either destroyed or simply chased away - and if no more targeting updates are given to the missiles while they're still half way to the target, at some 200 km - then the missiles may not get any more updates until they lock onto something on their own. Which opens to the door to jamming, decoys, various deceptions or even, theoretically, forces the missiles to do last minute turns to change their trajectory, and if that's done at the end of the potential range - the missile could miss altogether.

All in all, I would label YJ-12 to be somewhat more potent platform of the two. But at the same time, it's a bigger missile, double the weight, so it's simply not practical to be carried/used in similar numbers per launch platforms.
Click to expand...

Subsonic missiles need to have updates. The missile itself is blind in its subsonic state. It is only autonomous and live during its rocket boost stage. If the missile is flying lo-lo-lo, instead of a lo-hi-lo, the missile will be out of the LOS with the ship, and any update will require a plane or satellite proxy, with the ship sending the signal to the plane or satellite, then sent back down to the missile. Or you cannot update at all. To obtain updates, the missile has to fly a lo-hi-lo, and the missile must maintain a LOS with the ship, and as the Earth's circumference turns away, the missile has to raise its height proportionately.

Compared to the YJ-18, while the YJ-12 requires less updates and gets between A to B much faster, it also needs to fly higher. This means the YJ-12 will be detected earlier as it will be flying higher, as the missile flies over the radar horizon. The YJ-18 on the other hand, can fly lower in subsonic, and can stay lower, making it harder to detect until the missile flies over the radar horizon. Compared to the detection radius of the YJ-12, the YJ-18's detection radius would be closer to the target ship, along with a massive rocket powered sprint, the reaction time would be less.

If both missiles have to fly a lo-hi-lo approach, requiring updates on from the ship, the advantage may go to the YJ-12. But if the missiles can obtain updates through a flying or orbiting proxy, the advantage can go to the YJ-18, as it go to a lo-lo-lo cruise and sprint.

Ship to missile datalink itself would have a limited range, although the numbers to that range is unknown as it depends on the radiating power of the datalink array. There is going to be at some point, the missile has to get its updates over the horizon through a proxy.

If the missile is in a blind state, meaning the seeker is off, and there is no updates from the ship, one way to obtain updates is through ESM, using the target's own radar to locate the target. But you don't know if one particular missile would have this ability or not.

And of course, the missiles should have different modes to deal with a variety of ranges, including mid and close.
 
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T

Tam

Brigadier
Registered Member
plawolf said:
Can the YJ12 be launched from the new UVLS?
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Its a supersonic ramjet missile. The missile needs a minimum high speed to ignite its ramjet engines, and it may not get that with a vertical launch unless you got a really big booster. A required minimum high speed for jet engine ignition is also an issue with turbojet powered missiles, like the YJ-83 or YJ-62.

For an air breather to be VLS, you would want a turbofan, which requires a low flight speed to ignite the engine. The YJ-18's jet engine would have to be a turbofan along with any VLS launched cruise missile.
 
by78

by78

General
Re-posting some lost images of YJ-18.

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50534955232_d41796a122_k.jpg
 
T

Totoro

Major
VIP Professional
Tam said:
I would say about 25km to 35km for both missiles. No, it has nothing to do with the amount of propellant with the missile.
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For Klub missile it's really not debatable. Novator's own product promotional pamphlet says 20 km. Image of it here:
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If radar is at 15 m above horizon, then at 21 km the missile might do one last radar check as it crosses the horizon IF it flies at 2 m above water surface and a kilometer later the terminal stage might get ejected. If the missile flies at different altitudes or the radar is at different heights, then the calculus changes, as we know.

All this is applicable only to the Klub variant. It is theoretically possible that the russian navy Kalibr and the chinese navy YJ18 do feature somewhat different numbers.

For one, I would speculate that the expected tactical situation of late 1980s and early 1990s, for which Klub was originally developed - is different from one YJ18 development is trying to fight in. So, an accent on greater range is possible, even if it meant compromises. For example, making the warhead smaller and with less punch. Of course, this is complete conjecture.
 
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