Nuclear Triad In Place: India Gets K-4 SLBM Out Of The Closet

[Vasily Zaytsev]

Arming India


Nuclear Triad In Place: India Gets K-4 SLBM Out Of The Closet



By Vishal Thapar

NEW DELHI, SEP.23, 2015: For the first time, India has made the official declaration that its triad of nuclear weapons is in place. This significant announcement was made here today during the annual awards function of the Defense Research and Development Organisation (DRDO).

The veil was lifted off the hitherto secretive K-4 submarine-launched ballistic missile (SLBM), when a team of scientists from the Defense Research and Development Laboratory (DRDL), Hyderabad, was presented a special award for the design and development of the K-4 missile.



The range of this missile is over 3,500 kilometers, and it will be for the foreseeable future India's principal weapon of deterrence which can be fired from under the sea. The K-series of missiles has been nomenclatured after former chief of the DRDO and a popular President of India A.P.J.Abdul Kalam, and will arm the Arihant class nuclear submarines (SSBN).

TheAt the event, DRDO Director-General S.Christopher also made an important declaration of intent that the Arihant will be inducted for operational deterrence patrol in 2015-16. It is at present undergoing sea trials.



"It (the K-4) has enabled our nation to achieve the crucial nuclear triad," the DRDO citation stated. It acknowledged significant contributions made by DRDL scientist M.S.R.Prasad and his 62-member team towards the development of this key missile "under the Advance Naval Systems Programme (ANSP)".



The other SLBM in the K series is the K-15, which is reported to have a range of about 750 kilometers. Both the K-4 and the K-15 have been successfully test-fired multiple times from underwater pontoons to establish their capability to exit the water and then hit a target on land.



The underwater deterrence is the most crucial and reliable leg of the nuclear triad, ensuring maximum survivability of nuclear weapons against a decapitating first strike by a nuclear adversary. A robust SLBM is a shot in the arm for India's nuclear deterrence, and gives more credibility to its doctrine of 'No First Use'.

 

[amardeep mishra]

One of my colleges worked on the RCS of this missile system and in view this is undoubtedly one of the most complex strategic missile systems India have designed

 

[knight11]

Still lot of work has to be done and India have just reached one milestone before the triad is complete. Arihant is just the technology demonstrator and many critics says its underpower and the size compared to other nuclear submarine carrying SLBM of the nuclear power is small to carry more missile.

 

[amardeep mishra]

Still lot of work has to be done and India have just reached one milestone before the triad is complete. Arihant is just the technology demonstrator and many critics says its underpower and the size compared to other nuclear submarine carrying SLBM of the nuclear power is small to carry more missile.

You can't hope to develop the best SSBN in one go, it is a gradual and iterative process,However for current scenario arihant isn't bad at all, besides they're already working on the design of bigger SSBNthat will eventually carry 12 long range Slbms

 

[PARIKRAMA]

Thank You MSR Prasad and his 62 member team..
You had given us a significant national asset and has helped complete the triad..
we hope you continue your good work and mate the warhead with an MIRV multiplying its potential further..
God bless you and your team with all the love and success,,

 

[Ankit Kumar 001]

@amardeep mishra

Sir a small qery.
Like K15,when carrying maximum payload of 1000kg has the range of 750 km,and minimum with 180 kg , close to 1,500 km.

Similarly what is the range of K4 with minimum payload/warhead?

 

[kṣamā]

@amardeep mishra Bhai aap to gayab hi ho gaye the... Kitne dino baad dikh rahe ho...

 

[Srinivas]

we need a kind sub or a destroyer which can hold a medium sized country hostage.
we need bigger fire power. A triad with a sub of 4 missiles do not come under deterrence.

 

[amardeep mishra]

Similarly what is the range of K4 with minimum payload/warhead?

@kurup
Believe me,the topic of warhead specifications is so secret that any academic exercise to determine the payload can at best be described as speculative! Not even folks working on K4 would know the exact specification of the warheads it'll carry. Based on speculative analysis,and some of the published papers,one can say that K-4 has been designed with single warhead in mind and the range is 3500-4000kms.
K-5 will be india's true SLBM with 3 MIRVs and 6000+ kms range,now how will they achieve this?-it is an elaborate process involving optimization at various fronts ranging from
1)casing(composites instead of maraging steel)
2)newer high energy materials with higher specific impulse,
3)miniaturization of MEMS based sensors and actuators,
4)light weight reaction control systems etc.
with#1 and #2 contribute a lot in weight reduction of missiles,but that is not to say that #3 and #4 are insignificant.
One significant challenge with #1 is that with increased diameter strategic missiles the stresses acting radially on the casing is very high due to chamber pressure hence a thick walled maraging steel structure is prefered,but that increases weight significantly,hence the choice of an appropriate composite structure that can withstand high chamber pressure of first stage in our A5 system was a challenge that they painstakingly overcame.This will be implemented in newer missiles and will be called A6.
A6 is basically a highly optimized A5 with a host of improvements that render it a new missile altogether!
Another challenge with #2 is the type of solid fuel,as you know the shelf life of any missile is directly contingent upon the physical properties of the solid fuel.With canisterized A5 and A6 coming into picture,newer HTPB+AP compositions must be found that can hold the structural integrity for the required shelf life.
Now one would ask,why is structural integrity of solid propellants so important?Well the answer lies in the uniform burning or so called "regression rate-r" of solid propellants inside the missile.Any deformation in the surface would lead to significant increase in rate of burning and hence the chamber pressure.With age,the solid propellants are subjected to bending loads inside the missile due to gravity- this might develop minor cracks and crack provides extra surface area for burning- this in turn creates irregular regression rate and increased chamber pressure than desired.If allowed to go unabated,the chamber pressure might increase beyond the mechanical tolerances of the missile casing- especially during the initial phases when the thrust builds up very rapidly.
I'd also like to mention that in this regard russians are way ahead of us!
These few topics that i touched upon are very essential from the design aspect of a SLBM as well. If you are interested in detailed technical discussion,feel free to contact me!
Thanks in advance
Amardeep Mishra

 

[Ankit Kumar 001]

Thanks for such a detailed reply.
Another small query , like in case of K15 , it delivers a warhead of 180kg to its longest range, is it safe to assume that we have such a capable(meaning capable enough to do the required destruction) and miniaturized fission warhead?

 

[kṣamā]

These few topics that i touched upon are very essential from the design aspect of a SLBM as well. If you are interested in detailed technical discussion,feel free to contact me!
Thanks in advance
Amardeep Mishra

Why would you leave it hanging when you just started to describe the juicy parts!?!
Do you want us to beg?? Ok fine, Here I am begging you to keep going... Need to know the inticaies of the trade. How, Why, What, When.

 

[amardeep mishra]

Why would you leave it hanging when you just started to describe the juicy parts!?!
Do you want us to beg?? Ok fine, Here I am begging you to keep going... Need to know the inticaies of the trade. How, Why, What, When.

I can not answer like this,kindly pose specific questions my dear friend.It'll make my job easier,for instance that guy asked questions related to K-4 and warheads,i expect you to frame specific questions that i can deal with in some depth!
Thanks

 

[shaheenmissile]

For now its PLBM poontoon launched ballistic missile.
Does that count as deterrent?

 

[PARIKRAMA]

^^^
Troll attempt detected...
Users are requested to ignore...
Topic is good.. Participants are expected to be good... Lets keep discussions also good...

 

[amardeep mishra]

For now its PLBM poontoon launched ballistic missile.
Does that count as deterrent?

My dear friend, you'd need an under water platform to validate your missile.Arihant will eventually take K4 ,but when k4 was under development,arihant hadn't even begun the sea trials hence pontoons were choosen.
You need a proven submarine to test your new missile.
Having said that,K4 system is undoubtedly the most advanced strategic missile India has developed to this date,itz dimensions,degree of optimization and range will just boggle your mind