GOI's 1st official acknowledgement of the 'K4' long-range submarine launched nuke-capable missile

[kṣamā]

So now we have something bigger to go on arihant ?

 

[Ind4Ever]

Not that I know of. This mechanism uses boosters in the nose to "pull" the missile out of the water and gain some altitude. Historically, SLBM launches have been something like:
1. The submarine would surface, open hatches and launch missiles like a road mobile TEL.
2. The submerged-submarine would eject the missile out of the tube, and the missile's first stage would ignite while still in water.
3. Modern SLBMs are ejected by high-pressure gas-generating mechanisms out and above water (from upto 150ft depth). Once the missile clears water and stabilizes, the first stage is ignited.

EDIT: So I searched for that mechanism, it is called a cavitator (basically an explosive gas generator, which pushes the water aside to facilitate free upward motion of the missile, and is ejected after the missile's ejection). It is particularly associated with Russian SLBMs (R-39 Sineva).
However after comparing the Russian missile launches with this one, it seems that K-4's cavitator has much much more thrust, as it seems to physically propel the missile upward. Probably the design is a new or experimental one.

You are partially correct . The Cavitator pulls out the missile . But important point to note is that the video we watch was an experimental flight of India's oldest and advanced SLBM . Older than current K15(Which is a derivative of K4 for some reason may be with new technologies ) . The missile was launched from under water silo about 30 m as per some reports . SLBM are supposed to be launched from surface or from depth . Without getting spotted by enemy radars . So the Cavitator you was talking about is actually for that purpose. To propel the missile upward even under the water .

Verdict : This is a huge leap forward for India's Nuclear weapons development . Now Arihant or its later version can stay still for man weeks at times of war , fire the missile from depth (1,2,3,4) then vanish from the spot . New power projection for India like all other superpower.

 

[IND151]

Not that I know of. This mechanism uses boosters in the nose to "pull" the missile out of the water and gain some altitude. Historically, SLBM launches have been something like:
1. The submarine would surface, open hatches and launch missiles like a road mobile TEL.
2. The submerged-submarine would eject the missile out of the tube, and the missile's first stage would ignite while still in water.
3. Modern SLBMs are ejected by high-pressure gas-generating mechanisms out and above water (from upto 150ft depth). Once the missile clears water and stabilizes, the first stage is ignited.

EDIT: So I searched for that mechanism, it is called a cavitator (basically an explosive gas generator, which pushes the water aside to facilitate free upward motion of the missile, and is ejected after the missile's ejection). It is particularly associated with Russian SLBMs (R-39 Sineva).
However after comparing the Russian missile launches with this one, it seems that K-4's cavitator has much much more thrust, as it seems to physically propel the missile upward. Probably the design is a new or experimental one.

The submarine would surface, open hatches and launch missiles like a road mobile TEL.

That was case in regard of old SSBNs.

So I searched for that mechanism, it is called a cavitator (basically an explosive gas generator, which pushes the water aside to facilitate free upward motion of the missile, and is ejected after the missile's ejection). It is particularly associated with Russian SLBMs (R-39 Sineva).

Thanks, I learnt something new today.

 

[The Deterrent]

So what do you think is the pros-cons for this?

If the cavitator/booster is too large it might leave little space for a warhead, so there would be lesser probability that K-4 has MIRVs. All in all, I think it is an experimental system which might undergo limited production (just like Agni-IV), to facilitate the development of 6000km-ranged & 4-MIRVed SLBM.

You are mistaken. If you look at the video closely you will find that the Missile nose fires AFTER it has cleared the water.

Then the Nose engine fires up and pulls the missile up along with the engine at the base of the missile.

I suspect this is to ensure launch of missile even if the gas ejector does not fully eject the missile to required height. The Nose engine is probably designed to fire even under water and is to be ejected when the missile reaches certain hight. Possibly the ejection of the Nose engine will expose the Nose Aerospike designed to reduce drage and increase range of the missile.

You are right, I watched it frame by frame and it does in fact ignite after clearing water. So it is not a cavitator but a nose-based booster which provides initial boost and is ejected just before the first stage is ignited. Also notice that although it seems from the tail exhaust that the first stage has ignited, the full exhaust isn't initiated until the missile has attained the boosted height (just like the booster of BrahMos, it propels the missile upwards, "dials down", and after the pitch maneuver "dials up" to full exhaust again).

You are partially correct . The Cavitator pulls out the missile . But important point to note is that the video we watch was an experimental flight of India's oldest and advanced SLBM . Older than current K15(Which is a derivative of K4 for some reason may be with new technologies ) . The missile was launched from under water silo about 30 km as per some reports . SLBM are supposed to be launched from surface or from depth . Without getting spotted by enemy radars . So the Cavitator you was talking about is actually for that purpose. To propel the missile upward even under the water .

How is it older than K-15 (B-05)?
30 km what?!
Yeah that is what all modern SLBMs do except that they don't use any sort of nose-based booster. Rather the gas-generator thrust is enough to propel the missile out and clear of water.

That was case in regard of old SSBNs.

Yeah that is why I referred to it as "Historically, SLBM launches have been like.."

 

[kaku1]

If the cavitator/booster is too large it might leave little space for a warhead, so there would be lesser probability that K-4 has MIRVs. All in all, I think it is an experimental system which might undergo limited production (just like Agni-IV).

Actually I think, never K-4 Mk.1 planned for MIRV, and maybe even Mk.2 would not be MIRV. The SLBM based on Agni-6, which goes to big boomers would be MIRV.

How is it older than K-15 (B-05)?
30 km what?!
Yeah that is what all modern SLBMs do except that they don't use any sort of nose-based booster. Rather the gas-generator thrust is enough to propel the missile out and clear of water.


Yeah that is why I referred to it as "Historically, SLBM launches have been like.."

He means 30m,, but, I think still gas-generator of India is not on par of Russian or American. They need more development.

 

[IND151]

You are partially correct . The Cavitator pulls out the missile . But important point to note is that the video we watch was an experimental flight of India's oldest and advanced SLBM . Older than current K15(Which is a derivative of K4 for some reason may be with new technologies ) . The missile was launched from under water silo about 30 km as per some reports . SLBM are supposed to be launched from surface or from depth . Without getting spotted by enemy radars . So the Cavitator you was talking about is actually for that purpose. To propel the missile upward even under the water .

Verdict : This is a huge leap forward for India's Nuclear weapons development . Now Arihant or its later version can stay still for man weeks at times of war , fire the missile from depth (1,2,3,4) then vanish from the spot . New power projection for India like all other superpower.

People in Pentagon will faint if they hear this.

 

[Aamna Ali]

If the cavitator/booster is too large it might leave little space for a warhead, so there would be lesser probability that K-4 has MIRVs. All in all, I think it is an experimental system which might undergo limited production (just like Agni-IV), to facilitate the development of 6000km-ranged & 4-MIRVed SLBM.


You are right, I watched it frame by frame and it does in fact ignite after clearing water. So it is not a cavitator but a nose-based booster which provides initial boost and is ejected just before the first stage is ignited. Also notice that although it seems from the tail exhaust that the first stage has ignited, the full exhaust isn't initiated until the missile has attained the boosted height (just like the booster of BrahMos, it propels the missile upwards, "dials down", and after the pitch maneuver "dials up" to full exhaust again).



How is it older than K-15 (B-05)?
30 km what?!
Yeah that is what all modern SLBMs do except that they don't use any sort of nose-based booster. Rather the gas-generator thrust is enough to propel the missile out and clear of water.


Yeah that is why I referred to it as "Historically, SLBM launches have been like.."

Maybe it does not have Gas generator based ejection..because we have developed the canisterization technology only very recently and i highly doubt that it has been already minaturised enough to fit in the nuclear sub. Also the launch tubes are designed to carry either 4 k-15 or 1 k-4 per tube. Does the design suit gas generator ejection?

 

[Ind4Ever]

You are partially correct . The Cavitator pulls out the missile . But important point to note is that the video we watch was an experimental flight of India's oldest and advanced SLBM . Older than current K15(Which is a derivative of K4 for some reason may be with new technologies ) . The missile was launched from under water silo about 30 km as per some reports . SLBM are supposed to be launched from surface or from depth . Without getting spotted by enemy radars . So the Cavitator you was talking about is actually for that purpose. To propel the missile upward even under the water .

Verdict : This is a huge leap forward for India's Nuclear weapons development . Now Arihant or its later version can stay still for man weeks at times of war , fire the missile from depth (1,2,3,4) then vanish from the spot . New power projection for India like all other superpower.

30 m ... Not 30 KM typo error

People in Pentagon will faint if they hear this.

 

[possumlot]

Maybe it does not have Gas generator based ejection..because we have developed the canisterization technology only very recently and i highly doubt that it has been already minaturised enough to fit in the nuclear sub. Also the launch tubes are designed to carry either 4 k-15 or 1 k-4 per tube. Does the design suit gas generator ejection?

We have been doing canister based launches since 2001 You think 13 years is not enough to master the tech ?

 

[OrionHunter]

sideways thrusters for stability of missile Drdo should use thrust vector controls in main engine

As the size of rocket engines increase and due to specialized thrust vector control problems, additional emphasis is being given on thrust vector control by other than conventional means. One of the more promising means of thrust vector control is through secondary injection of either liquid or gas into the engine exhaust nozzle.

 

[Echo_419]

As the size of rocket engines increase and due to specialized thrust vector control problems, additional emphasis is being given on thrust vector control by other than conventional means. One of the more promising means of thrust vector control is through secondary injection of either liquid or gas into the engine exhaust nozzle.

The question is how fast can this missile be deployed on Arihant class subs & the follow on ones

 

[The Deterrent]

Maybe it does not have Gas generator based ejection..because we have developed the canisterization technology only very recently and i highly doubt that it has been already minaturised enough to fit in the nuclear sub. Also the launch tubes are designed to carry either 4 k-15 or 1 k-4 per tube. Does the design suit gas generator ejection?

May be.
That would be 3 K-15 or 1 K-4. The missiles are inserted with there own specific canisters/tubes into the submarine tubes. So in case K-15 are installed in a tube, each of the 3 K-15s will have there own tubes with independent pressure/ gas-generator ejection systems. For example, see the following image of Ohio-class SSGN's missile tubes:

In the left tube, 7 Tomahawk LACMs are present while in the right a single Trident-II SLBM is present.

 

[illusion8]

May be.
That would be 3 K-15 or 1 K-4. The missiles are inserted with there own specific canisters/tubes into the submarine tubes. So in case K-15 are installed in a tube, each of the 3 K-15s will have there own tubes with independent pressure/ gas-generator ejection systems. For example, see the following image of Ohio-class SSGN's missile tubes:

In the left tube, 7 Tomahawk LACMs are present while in the right a single Trident-II SLBM is present.

Traditionally Indian missiles are heavier in comparison, the nose boosters could be to avoid the excess after shocks that such a launch underground or in this case on the surface of the water with the sub not too deep enough to avoid the aftershock.

The aftershock from a full ignition and flame out would harm a stationery launch sub a few meters deep in the water...just a guess.

 

[amardeep mishra]

the full exhaust isn't initiated until the missile has attained the boosted height (just like the booster of BrahMos, it propels the missile upwards, "dials down", and after the pitch maneuver "dials up" to full exhaust again).

Yes that is absolutely correct the first stage rocket motor hasnt ignited untill the k-4 has achieved a stable height above water surface.

 

[gslv mk3]

this slide is from the drdo presentation
we will eventually have a missile with a range more than 6000 kms with 4 MIRV's (2000kgs)
that'd be a real game changer

Did anyone notice 'telescopic aerospike' ??