Behind the China Missile Hype

IronsightSniper said:

@plawolf, that idea is stupid.

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Ah yes, another well thought out, eloquently reasoned and thoroughly researched response from Ironsight.

You can't just stack APFSDS rounds together and hope they hit something. They have fins for a reason. If you were to stack them together, release them, they'd simple start doing dance moves mid-air and have a high probability of missing the target and even hitting the target with the wrong end of the penetrator.

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And all this is based on solid areodynamic theory and real world experience? If so, maybe you should present your scientific paper to the Israelis, as I am sure they should know that the 'beehive' round that they have been using for years doesn't actually work.

Not to mention that the DF-21D gets the majority of it's terminal velocity from either it's engines or simple gravity.

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Yet another well thought out and well research point. Aren't you just full of them these days?

For the record, the DF21 doesn't use an engine on the re-entry vehicle. It's terminal velocity is down entirely to 'simple gravity' and basic inertia.

Funny thing about gravity and inertia is that it acts the same on things no matter the mass. Some monk that you evidently never heard of demonstrated this simple fact a fair while back when he dropped two metal balls of greatly different size off a tower at the same time and they landed...wait for it...at the same time.

Maybe you should write a strongly worded letter to your local primary education provider for not including this most basic of facts in your primary education that resulted in you having such a poor understanding of the most basic of everyday physics.

Once you release submunitions, those submunitions will slow down because they don't have the mass or the shape of the DF-21D, not to mention the rocket engines, to go that fast. So if such a proposal were to even be utilized, it'd end in a total humorous failure.

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As explained before, mass has bugger all to do with how fast something falls to earth because of gravitational pull. Shaping will have an impact, and that is because of aerodynamics.

I would normally not bother to explain this, but with you, it seems best not to take anything for granted. But, shocking as it may seem, air resistence is dependent on surface area and speed. Since the sabots will be traveling at the same speed as the DF21 warhead upon release, the only difference would be as a result of the difference in surface area between a sabot, and the DF21 warhead itself.

I hope even you can figure out which of those has the greater surface area and thus the greater air resistence working against it, and thus which will slow down more because of air resistence.

But, again, very very basic maths would have told you that you are barking up the wrong tree even bring up lost speed as a result of air resistence.

Such a warhead would seperate at most a few km above the target. The optimal dispursal will have to be worked out with tests and computer modeling involving some very grown up maths, so I will just use 3.4km as an example (and a cookie for you if can figure out why I picked that height).

Sound travels at 340m/s, so M10 is 3,400m/s. That's one second between dispursal and impact. Even with just basic common sense, you should realize that any slowing down will have minimal effect on terminal velocity and KE.

Here is some free advice, make sure you have a clue before you go calling someone else's ideas 'stupid'.

plawolf said:

Funny thing about gravity and inertia is that it acts the same on things no matter the mass. Some monk that you evidently never heard of demonstrated this simple fact a fair while back when he dropped two metal balls of greatly different size off a tower at the same time and they landed...wait for it...at the same time.

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[video=youtube;5C5_dOEyAfk]http://www.youtube.com/watch?v=5C5_dOEyAfk[/video]

plawolf said:

Ah yes, another well thought out, eloquently reasoned and thoroughly researched response from Ironsight.



And all this is based on solid areodynamic theory and real world experience? If so, maybe you should present your scientific paper to the Israelis, as I am sure they should know that the 'beehive' round that they have been using for years doesn't actually work.

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Yet another well thought out and well research point. Aren't you just full of them these days?

For the record, the DF21 doesn't use an engine on the re-entry vehicle. It's terminal velocity is down entirely to 'simple gravity' and basic inertia.

Funny thing about gravity and inertia is that it acts the same on things no matter the mass. Some monk that you evidently never heard of demonstrated this simple fact a fair while back when he dropped two metal balls of greatly different size off a tower at the same time and they landed...wait for it...at the same time.

Maybe you should write a strongly worded letter to your local primary education provider for not including this most basic of facts in your primary education that resulted in you having such a poor understanding of the most basic of everyday physics.



As explained before, mass has bugger all to do with how fast something falls to earth because of gravitational pull. Shaping will have an impact, and that is because of aerodynamics.

I would normally not bother to explain this, but with you, it seems best not to take anything for granted. But, shocking as it may seem, air resistence is dependent on surface area and speed. Since the sabots will be traveling at the same speed as the DF21 warhead upon release, the only difference would be as a result of the difference in surface area between a sabot, and the DF21 warhead itself.

I hope even you can figure out which of those has the greater surface area and thus the greater air resistence working against it, and thus which will slow down more because of air resistence.

But, again, very very basic maths would have told you that you are barking up the wrong tree even bring up lost speed as a result of air resistence.

Such a warhead would seperate at most a few km above the target. The optimal dispursal will have to be worked out with tests and computer modeling involving some very grown up maths, so I will just use 3.4km as an example (and a cookie for you if can figure out why I picked that height).

Sound travels at 340m/s, so M10 is 3,400m/s. That's one second between dispursal and impact. Even with just basic common sense, you should realize that any slowing down will have minimal effect on terminal velocity and KE.

Here is some free advice, make sure you have a clue before you go calling someone else's ideas 'stupid'.

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Ah, another well thought out and scientifically probable reply from plawolf. Lets start by talkin about fins. There's a large, large difference between a flechette round and an APFSDS round. Time! What could it be? Size? Don't be obvious! Penetrator material? They could be the same... Well sir IronsightSniper, what could it possible be?! The answer is penetrator design. Even the PLA knows that penetrator design is one of the largest, if not the largest infact, contributors to penetration potential. That is why the PLA and the Russian Army has deviated from their 'ancient' short n' fat penetrators to the Western long n' skinny penetrators, because long and skinny (with dense materials, like DU/WHA) will penetrate more, will retain it's shape more, and will cause more adverse affect after penetration. So, again, why not just put long rods of DU/WHA, bundle them up and release them? Stabilization. One easily achieves stabilization via a rifled barrel, which, when stabilized, gives the round in the long run, far more accuracy at the terminal phase (which is why the British holds the longest ranged tank v. tank kill with their rifled gun and their HESH round). Fins also play a large part in stabilization, as they also impart the spin on the projectile (spin + fin = win!) In fact, one of the largest principles in spaced armor (i.e. armor with an air gap, such is common on all MBTs, even the Type 99), is the destruction of a penetrator's fins and the subsequent motion that which the penetrator undertakes in that air gap, thus the penetrator will actually start to yaw and go off course, penetrating more armor, weakening to even destroying it's penetrator tip, or even end up destabilized so much that it stops mid way through the armor.

So as you can see, simply stacking '1500' APFSDS penetrators and launching them is a stupid idea, at best.

And thank you plawolf for correcting me on the DF-21D's terminal phase. Your correction will go to show why you're wrong. Like you've said, gravity knows no mass. That is true. However, that is almost completely irrelevant. The reason? Because the DF-21D is not relying on gravity on that basic and simplistic sense. It is relying on it's terminal velocity, which is determined by gravity, but also by the object's shape, it's mass, the viscosity of the medium (in this case, air), etc. And remember, the terminal velocity is the maximal velocity that an object may have when free-falling in the Earth's atmosphere. Because the DF-21D's terminal bus (or perhaps there's no separation between the warhead and the terminal stage?) is free-falling within the atmosphere, it's mass; and it's payload's mass must be taken to account. I don't remember who exactly said it, but they proposed using multiple 0.5" diameter tungsten balls as the DF-21D's payload. A ball is actually better than say, an APFSDS round as this type of weapon, since a ball has a unitary shape, whilst an APFSDS pentrator is not uniform, and when off-set by something like say, falling, will tend to tumble and twirl and not hit with the end you want to hit with, whilst a ball will hit with any end and will the same as it would with any other end. In any case, I calculated that a 0.5" diameter DU ball (DU is technically a better penetrator material, and it was the only density out of the two that I remembered off the top of my head) will weigh about 20 grams. Moving at Mach 10, that equals to about 115 kj, or, half the KE of a 30 mm APDS round. The math for such a ball's terminal velocity comes out to a measly 72 meters per second. This doesn't mean of course, that when released from the warhead bus, that each ball decelerates to 72 meters per second instead of 3400 meters per second, but it does means that it will try to, and will continually decrease in velocity, exponentially lowering it's KE and subsequent damage.

And plawolf, I love how you pretend to sound like a father to me, even though I aptly described why the penetrator would slow down, and you but only rephrased me!

Once you release submunitions, those submunitions will slow down because they don't have the mass or the shape of the DF-21D

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the only difference would be as a result of the difference in surface area between a sabot, and the DF21 warhead itself.

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In any case, you are making a very common yet dead-wrong mistake. When you're in a car and you throw say, a bottle out of the window of the car, whilst the car is moving at 30 mph, that bottle will initially go 30 mph. Same is said for ejecting APFSDS rounds from the warhead of the DF-21D, whilst it's moving at Mach 10. Does this mean that the APFSDS round will be travelling at Mach 10? Certainly, for an infinitesimally short period of time. Upon ejection, the laws of physics will be at the helm, and those rounds will not be travelling at Mach 10 anymore. How fast they'll at impact? That's for some deeply interested guy to figure out, but it won't be at Mach 10, chances are, it would of had already started tumbling, and chances are, it's still a stupid idea.

IronsightSniper said:

Actually no. The problem with really small balls moving really fast is that they're actually easier to protect against. NASA uses what's called a whippy shield for their space ships, because that's literally all you need (thin pieces of aluminum and kevlar spaced apart) to stop extremely fast moving, yet small diameter micrometeroids from penetrating the hull. The hull of say, a Nimitz classed ship, is basically that, except thicker.

@plawolf, that idea is stupid. You can't just stack APFSDS rounds together and hope they hit something. They have fins for a reason. If you were to stack them together, release them, they'd simple start doing dance moves mid-air and have a high probability of missing the target and even hitting the target with the wrong end of the penetrator. Not to mention that the DF-21D gets the majority of it's terminal velocity from either it's engines or simple gravity. Once you release submunitions, those submunitions will slow down because they don't have the mass or the shape of the DF-21D, not to mention the rocket engines, to go that fast. So if such a proposal were to even be utilized, it'd end in a total humorous failure.

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Iron, I actually don't think so, 1/2" balls are not micro at all, they carry significant inertia at 20 grams each. Each one carries ~115,000 kJ of kinetic energy at mach 10 -> that is just a tad less energy than a 20 mm auto cannon round.

1/2" tungsten steel balls are basically 50 Cal rounds. 50 Cal API travelling at ~850 m/s can penetrate 20 mm of armor plate. A tungsten ball travelling at mach 10 ~3400 m/s or 4X the speed, would likely penetrate lets take a guess, 40 mm of armor plate?

Maybe 1/2" is too small, lets say 20 mm, balls, a German WW2 MG20 20 mm cannon with AP going at 1050m/s penetrates 40 mm of 30 deg slanted armor plate, so with 3X the velocity, lets say 80 mm of 0 deg armor? Breda 20 mm @850 m/s penetrate 30 mm of haredened armor, so performance should be in the ball park. -> energy wise it is only a tad less than a 37 mm cannon round. -> you are still getting 77,000 tungsten balls at 2 tons.

I doubt the island and fragile equipment will survive; nor do I believe flight opts can proceed with so many holes or dimples in the deck.

I think CVs have 2-3 inch of deck armor? If not, 30 mm tungsten balls can be used, looking at a guess penetration of ~140 mm of armor, with equivalent kinetic energy as a 57 mm round.

---------- Post added at 10:37 PM ---------- Previous post was at 10:23 PM ----------

IronsightSniper said:

In any case, you are making a very common yet dead-wrong mistake. When you're in a car and you throw say, a bottle out of the window of the car, whilst the car is moving at 30 mph, that bottle will initially go 30 mph. Same is said for ejecting APFSDS rounds from the warhead of the DF-21D, whilst it's moving at Mach 10. Does this mean that the APFSDS round will be travelling at Mach 10? Certainly, for an infinitesimally short period of time. Upon ejection, the laws of physics will be at the helm, and those rounds will not be travelling at Mach 10 anymore. How fast they'll at impact? That's for some deeply interested guy to figure out, but it won't be at Mach 10, chances are, it would of had already started tumbling, and chances are, it's still a stupid idea.

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I actually kinda disagree with you here, you made a very common mistake and that is, since the missile is at its terminal velocity under free fall. So if you let go of lets say a lead ball when you jump off a building, the lead ball and you will impact the ground at around the same time, and therefore at around the same speed.

If the aerodynamic profile of the object when they separate is more or less the same; they will have more or less the same terminal velocity, which in this case is Mach 10.

If you can accept a ballistic missile impacting at Mach 10 under free fall, so will whatever parts which separated from it.

I agree that there will be some difference, but in another light, lets say the separation occurs 0.5 km above the target to give sufficient dispersion, how much speed can the projectile loss in 140 mili second; lets say the impact at mach 8; that is still 2-3 times the velocity a APFSDS from a tank hit at.

Have you considered countermeasures like this as a means to screen the carrier and other ships against the terminal homing of ASBM?

".....Whereas smoke screens would originally have been used to hide movement from enemies' line of sight, modern technology means that they are now also available in new forms; they can screen in the infrared as well as visible spectrum of light to prevent detection by infrared sensors or viewers, and also available for vehicles is a superdense form used to prevent laser beams of enemy target designators or range finders on vehicles....."

Countermeasures like these will complicate the task of an ASBM to lock on to the carrier and begin its terminal dive

".....Moreover, the effectiveness of obscurants against a panoply of terminal homing systems, from the visual to the millimeter-wave spectrum, is proven. In simple terms, the particles suspended in the medium of smoke can be adjusted in size to absorb and diffuse radar waves emanating from the seeker heads of incoming antiship missiles, thereby denying any homing information to the missile...."

Remember the warhead has a very short time to discriminate between a real target and some large radar reflecting cloud.

Countermeasures using smart obscurants can render ASBMs nearly useless. If anyone disagrees the please state your case

Potential ASBM Countermeasures: “The Strategic Implications of ...
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NikeX said:

Have you considered countermeasures like this as a means to screen the carrier and other ships against the terminal homing of ASBM?

".....Whereas smoke screens would originally have been used to hide movement from enemies' line of sight, modern technology means that they are now also available in new forms; they can screen in the infrared as well as visible spectrum of light to prevent detection by infrared sensors or viewers, and also available for vehicles is a superdense form used to prevent laser beams of enemy target designators or range finders on vehicles....."

Countermeasures like these will complicate the task of an ASBM to lock on to the carrier and begin its terminal dive

".....Moreover, the effectiveness of obscurants against a panoply of terminal homing systems, from the visual to the millimeter-wave spectrum, is proven. In simple terms, the particles suspended in the medium of smoke can be adjusted in size to absorb and diffuse radar waves emanating from the seeker heads of incoming antiship missiles, thereby denying any homing information to the missile...."

Remember the warhead has a very short time to discriminate between a real target and some large radar reflecting cloud.

Countermeasures using smart obscurants can render ASBMs nearly useless. If anyone disagrees the please state your case

Potential ASBM Countermeasures: “The Strategic Implications of ...

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...

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Then it just becomes a question of the potency of the countermeasures vs the potency of the terminal sensors, assuming they have are forewarned, and have enough time to put up the necessary countermeasures.
It was mentioned a few years back AShBM's terminal sensors would be "multi mode" or something of that sort, where multiple types of sensors would act together. I imagine it means combining optical with IR, active radar etc

But the above discussion assumes AShBM is capable of reaching the carrier in the first place and is more about what kind of warhead could be best suited to strike carriers and other vessels with.

i belief only RF type can be use for missile terminal sensor. The heat from atomsphere will blind any IR sensor, visible spectrum sensor is not useful either.

with all the sensor, guidance system in the nose of missile, you probably want something compact for warhead. beside at that speed, the kinect energy itself is a warhead

Lezt said:

Iron, I actually don't think so, 1/2" balls are not micro at all, they carry significant inertia at 20 grams each. Each one carries ~115,000 kJ of kinetic energy at mach 10 -> that is just a tad less energy than a 20 mm auto cannon round.

1/2" tungsten steel balls are basically 50 Cal rounds. 50 Cal API travelling at ~850 m/s can penetrate 20 mm of armor plate. A tungsten ball travelling at mach 10 ~3400 m/s or 4X the speed, would likely penetrate lets take a guess, 40 mm of armor plate?

Maybe 1/2" is too small, lets say 20 mm, balls, a German WW2 MG20 20 mm cannon with AP going at 1050m/s penetrates 40 mm of 30 deg slanted armor plate, so with 3X the velocity, lets say 80 mm of 0 deg armor? Breda 20 mm @850 m/s penetrate 30 mm of haredened armor, so performance should be in the ball park. -> energy wise it is only a tad less than a 37 mm cannon round. -> you are still getting 77,000 tungsten balls at 2 tons.

I doubt the island and fragile equipment will survive; nor do I believe flight opts can proceed with so many holes or dimples in the deck.

I think CVs have 2-3 inch of deck armor? If not, 30 mm tungsten balls can be used, looking at a guess penetration of ~140 mm of armor, with equivalent kinetic energy as a 57 mm round.

---------- Post added at 10:37 PM ---------- Previous post was at 10:23 PM ----------



I actually kinda disagree with you here, you made a very common mistake and that is, since the missile is at its terminal velocity under free fall. So if you let go of lets say a lead ball when you jump off a building, the lead ball and you will impact the ground at around the same time, and therefore at around the same speed.

If the aerodynamic profile of the object when they separate is more or less the same; they will have more or less the same terminal velocity, which in this case is Mach 10.

If you can accept a ballistic missile impacting at Mach 10 under free fall, so will whatever parts which separated from it.

I agree that there will be some difference, but in another light, lets say the separation occurs 0.5 km above the target to give sufficient dispersion, how much speed can the projectile loss in 140 mili second; lets say the impact at mach 8; that is still 2-3 times the velocity a APFSDS from a tank hit at.

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I do apologize Lezt, I didn't imagine 0.5" diameter balls would hold much mass, but after doing some calculations for a DU ball, I was wrong, and that they do indeed have some great KE if launched from the bus of a DF-21D. However, you must remember that KE is not the only factor when it comes to penetration. There was a reason why the ole' spherical lead ball went out of date and the modern bullet-shape came to date, because the shape matters. Generally speaking, long and thin, dense and hard are the most prominent factors in penetrator characteristics that you'd want to pursue. You can fulfill the latter 2 with penetrator material, but a ball isn't going to penetrate as much as a long and thin stick.

But then again, we have to remember the scenario here. A 20 gram DU (or WHA, what have you) ball, moving at least Mach 3, will have more than enough penetration to at least, FUBAR the landing deck of a Nimitz class, destroy it's electronics, and any soft target. It's definitely not enough to sink the ship, but mission kill it, for sure. Though, I'd still scoff at the idea of any KE type warhead for the DF-21D. 130 kg of HE sank some British ships in the falklands, 300 kg of HE from a torpedo split a ship in two. A 600 kg warhead with a 40 m CEP accuracy is enough to severely damage a Nimitz class or even sink it. Throwing a mass of balls at it is just not even worth the price of launching it.

IronsightSniper said:

I do apologize Lezt, I didn't imagine 0.5" diameter balls would hold much mass, but after doing some calculations for a DU ball, I was wrong, and that they do indeed have some great KE if launched from the bus of a DF-21D. However, you must remember that KE is not the only factor when it comes to penetration. There was a reason why the ole' spherical lead ball went out of date and the modern bullet-shape came to date, because the shape matters. Generally speaking, long and thin, dense and hard are the most prominent factors in penetrator characteristics that you'd want to pursue. You can fulfill the latter 2 with penetrator material, but a ball isn't going to penetrate as much as a long and thin stick.

But then again, we have to remember the scenario here. A 20 gram DU (or WHA, what have you) ball, moving at least Mach 3, will have more than enough penetration to at least, FUBAR the landing deck of a Nimitz class, destroy it's electronics, and any soft target. It's definitely not enough to sink the ship, but mission kill it, for sure. Though, I'd still scoff at the idea of any KE type warhead for the DF-21D. 130 kg of HE sank some British ships in the falklands, 300 kg of HE from a torpedo split a ship in two. A 600 kg warhead with a 40 m CEP accuracy is enough to severely damage a Nimitz class or even sink it. Throwing a mass of balls at it is just not even worth the price of launching it.

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Iron, I agree, might as well put 2 ton of HE on top and a detonation near the ship will definitely seriously damage it (if not sink it) and the people on board.

The balls are just a curious solution, it would work, but there are easier ways to do it - i.e. HE

Lezt said:

Iron, I agree, might as well put 2 ton of HE on top and a detonation near the ship will definitely seriously damage it (if not sink it) and the people on board.

The balls are just a curious solution, it would work, but there are easier ways to do it - i.e. HE

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But what is HE intended for? for imparting some KE into shrapnel so that those otherwise harmless peices of metal could do some damage.

but wait we already have KE. so why waste it in an explosion.