Indian Naval Discussion

Karan M · Post by **Karan M** » 11 Apr 2012 19:36

Karan M wrote: How can a VLS missile with its radar be LOBL until & unless its radar is already cued to the target (which requires a LoS to the target). By their very nature these missiles will be LOAL, irrespective of who & what provides the initial guidance - onboard or offboard, till the seeker can acquire the target.

tsarkar wrote:No, you're wrong. Your understanding of LOBL is based on air launched ATGM, whose seekers are cued to targets by EO sight, and then launched.

However, LOBL capabilities are significantly considerable than that, and does not require LoS. The target bearing and approach coordinates can be fed into the missile before the missile leaves the VLS. Missiles like Barak-8 can be LOBL if target is designated while still within the launcher.

So, for a target approaching a fighter from the rear, a CCAAM can be cued by HMCS with target bearing before launch, and the missile on launch flips around 180 degrees to the coordinates fed into it before launch.

I checked for examples and found the following AWST article & reporter confirming what I've just explained http://www.aviationweek.com/aw/blogs/de ... 0c13dc0bbd

IAF and IA Spyder system Derby and Python missiles too stay inside cannisters without any LoS to target while data is fed into them during LOBL.

No, I am not wrong but you certainly are since you have mixed up LOAL and LOBL.

My understanding of "LOBL" is not just based on air launched ATGMs but AAMs and pretty much every missile that needs the sensor to lock onto the target before launch, which is what LOBL is.

Your explanation does not cover the very thing that LOBL is. "Lock on before launch" - which means the seeker is slewed to the target - any which way - and then acquires the target for a lock on!

Your citation of a missile with all aspect capability is also mistaken! The missile does a LOAL after it is launched and aligns itself to its likely target position based on whatever feeds it the info including the HMCS:

http://www.f-16.net/news_article2044.html

The Python 5 is quite revolutionary. New technologies implemented in the Python 5 give it maneuvering and launching skills unimaginable just few years ago. Instead of talking about certain "killing hemisphere" we are talking about an ability to shoot any target at any angle, including backwards launch. This ability is possible by applying LOAL (lock on after launch) technology. As opposed to LOBL (lock on before launch), that is used in all short range air-to-air missiles (excluding the Python 5 of course) in LOAL mode the pilot can launch a missile without being locked on the target, by getting the aircraft's estimated location from an array of sensors deployed on the launching aircraft.

So this was LOAL, and you mixed it up with LOBL!

Your explanation of this (http://www.aviationweek.com/aw/blogs/de ... 0c13dc0bbd ) is again not correct, because 1. These missiles are not VLS (note I specifically referred to VLS) and 2 In the picture as is obvious, the missiles can be slewed to the target and the pod covers are dropped for the seekers to acquire the target (LOBL) and hence target it! Clearly, this will only be done for targets which are relatively very near the missile and within its sensor coverage.

As matter of fact this is backed up by what your own link states: "If the target is within acquisition range the missile is launched in LOBL mode, and in the LOAL mode if the target is beyond seeker acquisition range."

Net: LOBL - Sensor locks on before launch! Sensor needs to have clear LOS to the target!

In the case of a VLS missile, there is one more factor.

The missile is vertically placed in its silo, so how can it acquire the target even if the cover is dropped UNTIL and UNLESS, the target is directly above the missile.

That's very unlikely to happen and so, its not LOBL in almost all of its operation but LOAL, where the missile is launched, cued towards the target (from any & whichever sensor data is fed to it) and then gets to the stage/distance where the sensor can acquire the target.

Hope this clarifies!

Here are some more examples....

Derby

Derby also has a programmable advanced electronic counter-countermeasures (ECCM) capability. Ben-Hanan said Derby can be operated in two modes. One is a lock-on after launch mode for long-range engagements in which the missile employs inertial guidance immediately after launch until the seeker is activated and homes in on the target. In the lock-on before launch for short-range engagements, Derby's seeker can be slaved to the aircraft's radar or the pilot's helmet mounted cueing system. The seeker is activated before launch and guides the missile all the way to the target.

Source: All over the place on Google

Or its SAAF variant, the V4R

It is capable of two modes: lock on before or after launch. In the lock-on before launch for short-range engagements, the seeker can be slaved to the aircraft's radar or the pilot's helmet mounted cueing system. The seeker is activated before launch and guides the missile all the way to the target .In lock-on after launch mode, for long-range engagements, the missile employs inertial guidance immediately after launch until the seeker is activated and homes in on the target.

http://www.saairforce.co.za/the-airforc ... 4-r-darter

Spike ATGM

Spike weighs just five pounds, but it’s a formidable weapon. The guidance system is highly original; in one mode it uses an electro-optical seeker, basically a video camera. Lock on before launch and it follows the target — even something agile like a motorbike. In another mode for night operation, the seeker can be set to home in on a laser spot, turning Spike into a laser-guided missile.

Source: http://www.wired.com/dangerroom/2008/10/more-bangs-for/

Maverick

For successful attacks against ground targets, the Federal Republic of Germany intends to procure TV-guided missiles of the type AN/AGM-65B MAVERICK. This missile is guided by a TV-seeker head with scene magnification. The weapon delivery is based on LOCK-ON-BEFORE-LAUNCH. The time between target recognition and launch is very tight, so that the weapon aiming procedure has to be as efficient as possible. This paper describes investigations to provide basic test data to assess different methods of target acquisition and missile seeker aiming and lock-on. In addition, the pilot workload with different controls and displays is assessed and methods of reduction derived. Different weapon information and Weapon-Video-Display-Systems and their advantages and disadvantages were investigated. The accuracy and speed of weapon aiming should be especially evaluated. Criteria for choice of display system are: pilot's workload, reaction time to lock-on, and possibilities of multiple target combat in the first attack.

Source:The Lock-on-Before-Launch Weapon Delivery and Display/Control Consideration

Even the F-22 had planned a trapeze launcher for LOBL
F-22 Raptor: Bill Sweetman, explaining the trapeze launcher originally planned for the Sidewinder, Page 50

The sidebays will each hold one sidewinder, carried on the AIM-9 Trapeze launcher....the trapeze launcher will extend automatically as the F-22 nears the point of achieving launch parameters on the target, allowing the infrared seeker to lock on before launch

Karan M · Post by **Karan M** » 11 Apr 2012 19:53

Here, from the horse's mouth itself...PR Blurb from Rafael..

The Spyder's LOBL explanation - exactly as I mentioned, Its turret'ed pods allow for the seekers to be pointed at the target, and hence LOBL. Nothing more, nothing less!

Note the exact comparison to vertical launch - that VL does not allow for LOBL! Not in practical circumstances anyway

http://sgforums.com/forums/10/topics/139653
All contents courtesy RAFAEL

RAFAEL has used the Israel Defense Forces experience while designing and developing the SPYDER system. SPYDER is a state-of-the-art low-level, quick reaction Surface-to-Air Missile System capable of engaging aircraft, helicopters, UAVs and PGMs. It provides excellent protection to valuable areas, as well as first-class defense for forces located in the combat area.

The SPYDER system incorporates RAFAEL's most advanced, state-of-the-art Air-to-Air Missiles the Derby, active radar (RF) missile and the Python-5, a dual band Imaging Infra Red (IIR) missile. Both missiles are the outcome of many years of research and development efforts utilizing the most modern technologies. SPYDER missiles have full commonality with the air-to-air missiles version.
The SPYDER launcher system is a 360ºxN electromechanical turret based unit. The system can launch missiles in slant method with two modes of operation: Lock-On-Before Launch (LOBL) and Lock-On-After-Launch (LOAL). This launching method enables the Lock-on-Before-Launch feature that cannot be achieved in vertical launch method. For this reason, many engagements can be carried out with the missiles seeker locked on the target before launch.

The advantages of LOBL are threefold:
It allows the Squadron Commander to positively confirm that the missile is locked on the target prior to launch
It increases the probability of kill (PK) for short range high manoeuvring targets.
It also enables designated targets engagement by add-on optical sensors.

In simple english. VLS does NOT enable LOBL unless target is directly above the VLS cell. Hence, the Spyder has a turret with its missile pods that can be slewed to the target, covers dropped, and the seekers can hence be locked onto the target..

http://www.army-technology.com/projects/spyder/

Modes of operation - Python 5 and Derby missile launcher

The system can launch missiles in two modes of operation: lock on before launch (LOBL) and lock on after launch (LOAL). The slant launching method, unlike vertical launch, allows LOBL so the missile's on-board seeker is locked on to the target before launch.

The LOBL mode allows the Squadron Commander to confirm the missile is locked on to the designated target prior to launch, gives high kill probability against short-range high-manoeuvring targets and enables the engagement of designated targets by add-on optical sensors.

Karan M · Post by **Karan M** » 11 Apr 2012 20:45

And here, the Nag - now updated with a new seeker that allows for LOBL at 4km, a significant achievement ..
http://www.thehindu.com/news/states/and ... 300985.ece

Nag missile, which has a range of four km, would be tested for its full range, two km and a minimum of 500 metres. This time DRDO scientists would demonstrate the lock-on-before launch capability of the missile for a four-km range with an upgraded imaging infrared seeker.

In lock-on-before-launch mode, the missile keeps acquiring the image of the target every 30 milliseconds right from the launch till the impact on target.

The missile would be fired to destroy both moving and stationary targets during the trials.

The shorter the range, the more difficult it would be for the missile to attack a moving target.

Mr. Chander said there was no other anti-tank missile in the world with a lock-on-before launch system for a four-km range.

The U.S. Javelin and the Israeli Spike had lock-on-before launch systems but the range was only 2.5 km.

He said it was also being planned to have the lock-on-before-launch capability for a seven-km range of the missile.

In recent field trials, the lock-on-after-launch capability of the Helina missile (airborne version of Nag) was proved.

member_20163 · Post by **member_20163** » 11 Apr 2012 20:58

^^^^^ Great job -- Fantastic news - i read somewhere earlier that Helina would be tried in LOBL mode. Awesome.... Cheers

krishnan · Post by **krishnan** » 11 Apr 2012 21:30

In lock-on-before-launch mode, the missile keeps acquiring the image of the target every 30 milliseconds right from the launch till the impact on target.

So how come its LOBL ???? Its already launched

Rahul M · Post by **Rahul M** » 11 Apr 2012 21:38

LOBL simply means initial target acquisition is achieved before launch, and the missile does not need to be manually updated throughout its flightpath. of course it would keep re-acquiring the target throughout the flight, not doing so would be stoopid. (*) without continuous real time acquisition of target info target might be in next village by the time the missile arrives.

(*) the problem with DRDO press releases is that they release too much info for us mango people to digest and we end up blaming them. our fault, not theirs. in western/russi publications this would be simply called "locked on target" and we would go home happy. DRDO OTOH tells us the nitty-gritty, the refresh time and we claim it's not LOBL.

pankajs · Post by **pankajs** » 11 Apr 2012 21:48

On LOBL

Nag in crucial stage of testing

The ‘lock on before launch' gives a tactical advantage. The missile acquires the image of the target before launch and keeps updating as it seeks and hits the target with precision. The DRDO has also developed the imaging infrared seeker technology. The private sector is integrating this capability into the higher range nag missiles as well.

SNaik · Post by **SNaik** » 12 Apr 2012 00:40

Vikram underway for de-Gaussing

SNaik · Post by **SNaik** » 12 Apr 2012 00:40

Vikram underway for de-Gaussing

tsarkar · Post by **tsarkar** » 12 Apr 2012 01:12

^^ Karan, whatever you've posted, I fully agree for seeker lock. I am referring to missile lock, viz, missile being fed bearing, azimuth and approach of threat before launch and the missile knowing where it needs to go before launch. Or which target has been allocated to it in a saturation attack. Barak-8 is supposed to do this. AAD already does this.

I got the incorrect impression from AWST that Spyder also had this, but they use good old seeker lock.

Python and R-73 (that had this capability before Python) is cued by Helmet Mounted Cueing System and knows where to go before its launched. So its locked to the target by the HMCS.

Older missiles, say Sidewinder or Magic, whenever their seekers were locked to a target's IR signature, the pilot got a tone and fired. This was seeker LOBL. From your post, I get the impression that Spyder does something similar. This is not anything radical, this is 60's tech. If the Sidewinder or Magic was fired with the target in the seeker FoV but without locking, then it was LOAL. In 1971 the Indian MiG21 fired its missiles and the missile failed to lock on th F104 that was finally shot down by gunfire.

andy B · Post by **andy B** » 12 Apr 2012 07:25

Gents,

Was thinking yesterday about what IN should be getting around in 2012 in terms of fleet strength.

From a first glance there should be:

- Two 11356 frigates (?)
- Chakra
- Arihant
- Two Shivalik class frigates (?)
- Vikramaditya
- One P15 A (?)
- Any P28s (?)
- Additional Mig29Ks (?)
- P8-I Neputnes (?)
- Any new Rotary assets (?)

SNaik, Tsarkar, Chacko, etall appreciate if you could put forth any additional dates and platforms to be deliverd this year...

(Srai not sure if you have an updated delivery schedule table saar)

The above is a massive combat boost potential IMO especially in a qualitative sense given the capabilities that these platforms bring to the IN...

arun · Post by **arun** » 12 Apr 2012 07:30

At long last some movement on the expansion of INS Kadamba at Karwar.

RFI Tender issued seeking EOI’s for the appointment of a technical consultant for phase 2A of Project Seabird.

A Naval Air Station is also comming up as a part of Phase IIA which is slated to cost INR 10,000 crore and be executed over 10 years.

Excerpt:

2. Objectives of Phase IIA

2.1 Project Seabird Phase IIA works will involve construction of a wide range of new facilities and augmentation of certain existing facilities involving an outlay of over Rs 10000 Crs (approx 2.2 Bn USD). Detailed Project Reports (DPRs) have been made and the required facilities have been divided into various work packages based on nature of work, expertise required and location. The envisaged facilities are intended to meet the following Project Objectives:-

(a) Provide requisite berthing and operational Fleet Base facilities/complexes for the operation, administration and Command & Control of over 30 capital warships/submarines, associated seaward defence and support/ yard craft at the Naval Base, Karwar.
(b) Augment available facilities for dry berthing of ships and provide Dockyard repair/maintenance facilities (up to level IV) for the warships, submarines/other craft based at Karwar and support (up to level II) for other visiting warships/submarines.
(c) Provide requisite facilities for all the necessary operational and logistic support to ships, submarines and various units based at Karwar including those related to the armament requirements of the units based at Karwar.
(d) Establish a Naval Air Station at Karwar for basing and operation of fixed and rotary wing ship/shore based military aircraft.
(e) Provide residential facilities and associated township infrastructure for the large number of Naval officers, sailors and civilian staff employed at the Naval Base. This includes substantial augmentation of the existing Naval Hospital.
(f) Provide adequate Communication, IT and security facilities required for the efficient operation, management and security of a large and widely spread Naval Base.

3. Purpose

3.1 The DPR for Phase IIA of the Project has identified Marine Works as a critical activity of the Project in order to adhere to the project timeframe desired by the Indian Navy.
3.2 Accordingly, the purpose of this Expression of Interest (EoI) is to enable shortlisting of reputable and capable consulting firms/institutions/consortiums, etc. with proven track record, which could be appointed as a Project Management Consultant
cum Marine Works Design Consultant (PMC & MWC) for Phase IIA of Project Seabird.
3.3. A detailed Request For Proposal (RFP) will be subsequently issued to the short-listed firms and proposals evaluated as per extant Government of India guidelines for the selection/appointment of the PMC & MWC.

4. Technical Details of The Project Phase IIA
4.1 Duration

4.1.1 The Project Seabird Phase IIA facilities are planned to be designed and constructed under various work packages, which are expected to be progressed simultaneously, to ensure the operational availability of all of essential facilities in approximately eight years, with the work on some of the lesser important facilities extending for another two/ three years thereafter.

4.2. Scope of Works

4.2.1. The main work packages are broadly described as follows:-

(a)Marine Works includes:-
(i) Dredging of over 80 million cum in the existing harbour area/approaches, reclamation of over 50 Ha of land and substantial associated revetments.
(ii) Construction of additional piers/jetties to provide approximately 4 km of berthing space for vessels along with associated network of utilities ducts and provision of a variety of shore services (such as fuel, power, fresh/sea/fire fighting water, HP/LP air, chilled water/air, sewage collection and disposal, shore communications/networking etc) to vessels berthed alongside.
(iii) Quarrying for approximately 4 million cum of stone aggregates within the Project area.
(iii) Setting up of navigation aids for safe movement of vessels in the Naval Harbour and its approaches.

(b) Fleet Base Buildings includes:-
(i) Construction of complexes/offices for the operation, management, logistic and maintenance support facilities (up to second line/ I level) to ships/ submarines; Naval Communication Transmission/Receiving stations; centralised monitoring/control of overall security within the Naval Base.
(ii) Provision of civil works and equipment related to the general and specialist facilities detailed above, as required for the operation, command & control/administration of a fully operational Naval Base and the Fleet based therein.

(c) Dockyard includes:-
(i) A comprehensive Dockyard capable of undertaking up to IV level/deep repairs/maintenance of gas turbine and diesel engine propelled ships & submarines
(ii) Various workshops equipped with necessary equipment, jigs, fixtures, tools and facilities to undertake refit of hull, engineering, electrical, weapons and control equipment / systems of various vessels.
(iii) Complexes/facilities for planning, management, administration, logistics, training, security, communication & IT, design/relocation of
some existing facilities.

(d) Dry Berths. A 10,000 Tonne Ship-lift with limited numbers of Dry Berths already exist at Karwar. This is to be augmented with development/construction of additional covered Dry Berths, Transfer Bay and associated equipment/services.

(e) Naval Air Station. This includes:-
(i) Development of a Naval Air Station in a 52 Hectare hitherto virgin area for operations/maintenance and support of fixed/rotary wing aircraft.
(ii) The above includes runways, hangars, ATC tower, navigation aids, MET facilities, equipment, offices, accommodation, logistic support, communication, IT, security, services, roads and flyovers.

(f) Armament Facilities includes:-
(i) Augmentation of specialised facilities for storage/maintenance/testing and inspection of various types of ammunition

From here:

EOI FOR TECHNICAL CONSULTANCY SERVICES FOR PHASE IIA OF PROJECT SEABIRD

Vipul · Post by **Vipul** » 12 Apr 2012 07:53

Frigate INS Teg to join Indian Navy on April 27.

INS Teg, the first of the three new Talwar class guided missile frigates, being built by Russia for the Indian Navy, has completed sea phase acceptance trials.

According to Yantar Shipyard, all that remained was to finish the interior premises and present operational documents to the crew.

The frigate's acceptance took place in the Baltic Sea. The trials began on 5 March and ended on 7 April.

The shipyard said all shipboard systems including armaments were tested in the presence of the customer's state commission and INS Teg proved herself to be fully ready for final stage of acceptance trials which started on Monday.

The handover ceremony of INS Teg to Indian Navy will be held on 27 April at Yantar Shipyard.

In 2006, India and Russia signed a $1.6 billion contract for the construction of three modified Krivak III class guided missile frigates.

INS Teg was laid down at Yantar in 2007 and became the first of three Project 1135.6 ships built for Indian Navy. The other two frigates - INS Tarkash and INS Trikand - are still at various stage of development at Yantar shipyard.

Nick_S · Post by **Nick_S** » 12 Apr 2012 12:13

Another Vik pic - http://balancer.ru/forum/punbb/attachme ... download=2

The superstructure is massive compared to the deck space. How many Migs can it hold on the deck? 6 max ?

Singha · Post by **Singha** » 12 Apr 2012 12:28

is this degaussing supposed to make less detectable by the seeker heads of torpedoes? I thought torpedoes can home in on prop sounds alone.

for a sub I agree it makes sense as they need to avoid MAD sensors....not an issue for surface ships which can be seen alone.

I would like to see something like this on IN P28, P17 and P17A+ ships atleast....
http://en.wikipedia.org/wiki/Prairie-Masker

Suraj · Post by **Suraj** » 12 Apr 2012 12:42

Degaussing also helps against mines.

SNaik · Post by **SNaik** » 12 Apr 2012 13:25

Nick_S wrote:Another Vik pic - http://balancer.ru/forum/punbb/attachme ... download=2

The superstructure is massive compared to the deck space. How many Migs can it hold on the deck? 6 max ?

Is this an answer?

http://balancer.ru/forum/punbb/attachme ... download=2

SNaik · Post by **SNaik** » 12 Apr 2012 13:28

Suraj wrote:Degaussing also helps against mines.

De-Gaussing is reduction of magnetic signature of the ship, a standard counter-mine procedure.

sombhat · Post by **sombhat** » 12 Apr 2012 15:07

SNaik wrote:Vikram underway for de-Gaussing
http://s56.photobucket.com/albums/g191/snake65/?action=view&current=detail177097.jpg

What is that light house like structure behind the island, or am I seeing things.

SNaik · Post by **SNaik** » 12 Apr 2012 15:44

sombhat wrote:
SNaik wrote:Vikram underway for de-Gaussing
http://s56.photobucket.com/albums/g191/snake65/?action=view&current=detail177097.jpg
What is that light house like structure behind the island, or am I seeing things.

Not sure about the exact composition of equipment on that mast, but supposedly it has to do with ATC, instrumental approach and landing of aircraft.

Nick_S · Post by **Nick_S** » 12 Apr 2012 17:03

SNaik wrote: Is this an answer?
http://balancer.ru/forum/punbb/attachme ... download=2

Thank you. Excellent answer.

---

BTW, will it be fitted with Barak-1 once it arrives in India? I suppose the Barak battery would come from Viraat..??

Singha · Post by **Singha** » 12 Apr 2012 17:05

but wouldnt mines be equipped with a propeller noise sensor in addition to a magnetic detector to target even plastic hulled MCMV boats?...esp the vicious bottom moored captor mines that release a light torpedo?

http://www.fas.org/man/dod-101/sys/dumb/mk60.htm

SNaik · Post by **SNaik** » 12 Apr 2012 17:56

Singha wrote:but wouldnt mines be equipped with a propeller noise sensor in addition to a magnetic detector to target even plastic hulled MCMV boats?...esp the vicious bottom moored captor mines that release a light torpedo?
http://www.fas.org/man/dod-101/sys/dumb/mk60.htm

Ther's still a lot of cheaper ones floating around

chackojoseph · Post by **chackojoseph** » 12 Apr 2012 18:31

Indian Navy installs damage control simulator “Avinash”

tsarkar · Post by **tsarkar** » 12 Apr 2012 18:44

Nick_S wrote:BTW, will it be fitted with Barak-1 once it arrives in India? I suppose the Barak battery would come from Viraat..??

That is the talk on the deck. Vikramaditya + Teg class + INS Mumbai will get their fit from Viraat + Godavari class +INS Ranvir/Ranvijay as they decommission later this decade.

Aditya G · Post by **Aditya G** » 12 Apr 2012 19:49

sombhat wrote:
SNaik wrote:Vikram underway for de-Gaussing
http://s56.photobucket.com/albums/g191/snake65/?action=view&current=detail177097.jpg
What is that light house like structure behind the island, or am I seeing things.

Infact the mast is almost as tall as the island. Havent seen anything like it in any other warship. It is visible hear as well:

http://balancer.ru/forum/punbb/attachme ... download=2

She is quite a looker ... aint she

Aditya_V · Post by **Aditya_V** » 12 Apr 2012 19:53

I think given we don't have e 2c's and E2D's, it is an attempt to get the Radar as High as possible to detect low flying aircraft and CM as far as possible.

SNaik · Post by **SNaik** » 12 Apr 2012 20:40

Aditya G wrote:
Infact the mast is almost as tall as the island. Havent seen anything like it in any other warship. It is visible hear as well:

http://balancer.ru/forum/punbb/attachme ... download=2

She is quite a looker ... aint she

US carriers have similar mast, just of a lighter construction.

Prem Kumar · Post by **Prem Kumar** » 12 Apr 2012 21:58

Singha wrote:but wouldnt mines be equipped with a propeller noise sensor in addition to a magnetic detector to target even plastic hulled MCMV boats?...esp the vicious bottom moored captor mines that release a light torpedo?
http://www.fas.org/man/dod-101/sys/dumb/mk60.htm

I had a noob question for a long time and this post triggered the thought again: how about a torpedo that acts in the following manner. Lets say an aircraft carrier is detected and its bearing is known. About 100 miles ahead of its predicted path, an SSN would release a few "special torpedos". These torps would swim out of the SSN (I know swim-out torps exist) and align themselves slowly so that their cone of detection would cover the approaching AC, allowing for error in path prediction.

The sub swims away because we dont want it in the scene of action when the fun begins.

Basically these torps act as mines with their propulsion in say an "idling" mode, so that it will be very difficult to detect them. When the AC is within a no-escape zone, the torps go full steam for the kill. It will give too little time for counter measures. The SSN is far away, making its detection difficult by ASW advance scouts trying to clear the area.

Another variation is for the SSN to keep spooling out a wire to these torps while it swims away, so that it keeps feeding the target bearing for as long as possible.

Its similar to the Captor mine concept, except the torp acts a combination of torp+mine and isnt moored.

Is this workable?

Singha · Post by **Singha** » 12 Apr 2012 22:12

a torp cannot idle. it has to move using props or float using airbags to generate lift I think, else it will sink like a stone.

Prem Kumar · Post by **Prem Kumar** » 12 Apr 2012 22:54

Ok - but cant it move in say slow circles, so that it floats & at the same time its props arent making that much noise for it to be detected

negi · Post by **negi** » 12 Apr 2012 22:58

Well if it is wire guided torpedo then it's constrained by the length of the cable, if it's active homing then it will get detected first by it's acoustic ping instead of the noise generated by it's props.

In your scenario IMHO the best bet is to feed in the coordinates to a WAKE homer and position it somewhere behind the ship and let it then follow the wake.

Angre · Post by **Angre** » 12 Apr 2012 23:57

... or like the Mk48 ADCAP, the wire can be cut when the torps's internal guidance locks-on to the target. Range ~5 miles for the Mk48 AFAIK.

NRao · Post by **NRao** » 13 Apr 2012 04:33

Prem Kumar wrote:Ok - but cant it move in say slow circles, so that it floats & at the same time its props arent making that much noise for it to be detected

Looking for an armed unmanned underwater vehicle?

srai · Post by **srai** » 13 Apr 2012 05:53

Prem Kumar wrote:...

I had a noob question for a long time and this post triggered the thought again: how about a torpedo that acts in the following manner. Lets say an aircraft carrier is detected and its bearing is known. About 100 miles ahead of its predicted path, an SSN would release a few "special torpedos". These torps would swim out of the SSN (I know swim-out torps exist) and align themselves slowly so that their cone of detection would cover the approaching AC, allowing for error in path prediction.

The sub swims away because we dont want it in the scene of action when the fun begins.

...

Is this workable?

Current generations of heavyweight torpedos only have a maximum range of 50km. A range of 100 miles (160km) is a lot based on the limitations of current torpedo technology. Another limitation would be the size of the sonar in the torpedo and hence its ability to detect targets at a given range will be limited ... unless there is a way for the parent submarine to provide a mid-course guidance. Then this torpedo would also need to counter decoys, which would be much more effective against smaller torpedo sensors and the targets have a lot of time to launch a wide array of counter-measures. The torpedo would also need to be fast enough to catch the target ships that will most likely make a sprint dash upon detecting the torpedo.

Also, without some sort of a "target noise signature lock" in the proposed torpedo, it will be a "loose" torpedo that has a long swim time. It would be potentially dangerous to every ship/submarine around its 100 miles radius if it does not know who it was targeted at and tries to find the next available target. It would need a mechanism to self-destruct.

One solution, as NRao has pointed out, would be to have "mini-autonomous underwater vehicle" with its own sensors and a payload of 2 to 4 lightweight torpedos. The navy can launch these platforms in a given area for them to patrol for a long time (maybe up to 72 hours at a time). If these vessels detect a particular threat noise signature within its patrol vicinity, they would launch their torpedos from a close range (within ~10km). These vessels should be able to be retrieved after a given period of time to be refueled or reloaded or relocated.

negi · Post by **negi** » 13 Apr 2012 07:49

The Ru Type 65 claims to have a range of 100km when cruising at ~20 knots.

Singha · Post by **Singha** » 13 Apr 2012 10:02

its 23" diameter and longer than the typical 21" x 18ft HWT. a unique anti-ship only weapon fired by the biggest russian subs only. will not fit into any SSK design for sure.
it is unlikely to catch a alert SSN in a tail chase hence Rus SSNs carry the regular 21" HWT too.

khan had a range of measures to deal with this, incl towed sonars to catch its approach and softkill stuff CH53s hovering over its expected path from behind the carrier to create a disturbance in the water similar to prop turbulence and then slowly deviating to 'lead' the torpedo away by confusing its wake homing sensor.

koti · Post by **koti** » 13 Apr 2012 10:06

Prem Kumar wrote: I had a noob question for a long time and this post triggered the thought again: how about a torpedo that acts in the following manner...........

I have some fantasy/idea too

A semi/full submersible vessel with minimal detectability carrying a single BMos with average range capable of traveling a little distance or loiter an area after being launched from a parent Sub/Ship/Plane. Once it gets its co-ordinates from a Sat/AEW down link, it can launch its missile and die. It shall be good against ACs.

adityadange · Post by **adityadange** » 13 Apr 2012 11:17

koti wrote: I have some fantasy/idea too
A semi/full submersible vessel with minimal detectability carrying a single BMos with average range capable of traveling a little distance or loiter an area after being launched from a parent Sub/Ship/Plane. Once it gets its co-ordinates from a Sat/AEW down link, it can launch its missile and die. It shall be good against ACs.

I think when it comes to threats from aircraft carriers to india in coming decade are from chinese carrier only since there seems little or no way that any country having AC except china is going to fight against us. pakistan definately cannot afford such huge investment. even it will take at least 5 years for varyag or any follow-on chinese carrier to pose real threat. this is allowing us time to start work on specific counter-carrier weapon. and for few more years air launched brahmos can do the job. we should look forward to integrate brahmos to p8-I type of aircrafts. even 3-4 missiles on a plane will suffice need to the hour. and in the meantime research on better torpedo technologies.

koti · Post by **koti** » 13 Apr 2012 11:53

True.
But what I said can be seen from a next gen Naval Mine concept.