Kalvari Class Submarines - Updates & Discussions



The only question is ... Whats the Timeline are we looking at ? atleast for the F21 ie when can see the test, procurement and induction?
Testing is not an issue because french and Brazilian navies already ordered F21 HWTs.
The F21 was developed as a serious counterpart and replacement for Black Shark torpedo. The F21 shares too many similarities with the Black Shark, including an electric motor driven by an aluminium silver-oxide battery.

For procurement and Induction: Its developmental trials are recently completed and 2 months ago, DCNS also offered it for IN's subs (scorpene class). So, it should not take more time to seal the deal. Most possibly, we will have F21 deal clubbed with the P75 extension (3 more scorpene class subs) in near future.


Call Sign "RED"
Dec 2, 2017
Testing is not an issue because french and Brazilian navies already ordered F21 HWTs.
The F21 was developed as a serious counterpart and replacement for Black Shark torpedo. The F21 shares too many similarities with the Black Shark, including an electric motor driven by an aluminium silver-oxide battery.

For procurement and Induction: Its developmental trials are recently completed and 2 months ago, DCNS also offered it for IN's subs (scorpene class). So, it should not take more time to seal the deal. Most possibly, we will have F21 deal clubbed with the P75 extension (3 more scorpene class subs) in near future.
I hope you are right!!! (y)
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Latest Images of INS Kalvari .
It will be Indian version of Naval Group Scorpene .
Image credit- livefist





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INS KALVARI Timeline -

14 Dec 2006 First cutting of steel .
06 April 2015 Moved out of Drydock .
27 Oct 2015 launched and christened as INS kalvari.
01 May 2016 Began sea trials .
02 Mar 2017 Maiden Exocet SM39 Missile firing
26 May 2017 Maiden Torpedo Firing
14 Dec 2017 Commissioned into service


Image credits MDL
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Active member
Dec 4, 2017
This is indeed a great day for India. However, I just have one nagging worry- The Scorpene data leak. Hope the Navy has done all that was needed to mitigate the effects of that.


Staff member
Nov 30, 2017
The many minefields and torpedoes INS Kalvari skirted before the Modi commissioning

The Kalvari or Scorpene deal faced attacks on all sides— by politicians, the bureaucracy, CAG and even CBI since its controversial signing in 2005.
New Delhi:
The minefields and torpedoes that INS Kalvari survived before its commissioning by Prime Minister Narendra Modi Thursday would have capsized many a sturdy boat and sunk more than a few hearts.
The latest conventional submarine to join the Indian Navy—after an almost two-decade gap that saw the last new Russian origin Kilo class getting commissioned—has had an unsteady 12-year run through the Indian defence procurement system.
The Kalvari or Scorpene project faced attacks on all sides—by politicians (from the BJP incidentally), the bureaucracy, the auditor general and even a surprise assault by the CBI since the controversial signing of the deal in 2005.
First strike
While it was signed in 2005, the Scorpene deal had a few similarities with that of the Rafale fighter jet and the controversy that now surrounds it. It involved a government-to-government deal with the French, chosen despite strong protests from the Germans who were offering the HDW 214 class with transfer of technology.
The main opposition party, convinced that there was a scandal in the contract, launched a frontal offensive alleging overpricing and corruption. In this case, the opposition was the NDA and leading the attack were stalwarts such as George Fernandes. Under attack was the then defence minister Pranab Mukherjee.
In March 2006, the BJP launched a particularly strong attack on the Congress for alleged corruption in the Scorpene deal. The face of this assault was then party spokesperson and current Union minister Prakash Javadekar.
The Congress government, however, stuck to its guns and went ahead on the procurement. What this unleashed was a massive campaign against the Scorpene deal.
Enter the dragon
The political storm was weathered by the UPA and Mukherjee but not before the CBI and the CAG took a shine to the case. The CBI inquiry into the infamous naval war room leaks case was directed towards allegations of corruption and bribery in the Scorpene deal as well.
However, in July 2008, the CBI informed the Delhi High Court that it found no evidence of kickbacks or money laundering in the Scorpene deal.
The respite was short lived, however, with the CAG coming down hard on the government in July 2009 for “undue favours” to French firms and an increase in costs. The CAG listed four major issues:
— Price increased by Rs 2,383 crore as the government took nine years to conclude the deal.
— The Navy and defence ministry diluted requirements to favour French firms in the acquisition process.
— The French side was given undue financial benefits, specially a price escalation clause of 11.06 per cent.
— A clause banning commissions to agencies was not signed.
Hitting the speed barrier
By 2010-11, it became clear that the Scorpene project was hopelessly behind time. Originally scheduled to be inducted in 2012, the project got delayed by five years due to trouble in absorbing technology and production issues.
In 2011, a big setback occurred with a massive breach and flooding at the Mazgaon Docks Limited (MDL) where the submarines were being made. The breach of the dry dock was one of the several technical issues that hit the Scorpene project, other being delays in ordering equipment from France and labour-related issues.
According to the original contract, the first Scorpene had to come by December 2012, followed by one submarine a year and the entire fleet to be inducted by 2017. With all this clearly appearing impractical, plans were redrawn, to change the delivery schedule.
An upset Navy demanded the first boat by 2015, a deadline that was again not met. It was in August 2015, however, that the first boat was launched in water, paving the way for trials and subsequent commissioning.
The Agusta shadow
The shadow of the AgustaWestland VVIP chopper scam was also looming over the Scorpene deal. The main weapon of the submarine, Black Shark, was selected in advance.
The Black Shark—a heavyweight torpedo to take down enemy ships and submarines—is made by Italian company WAAS, a subsidiary of Finmeccanica, the Italian parent firm of AgustaWestland. However, with the Agusta controversy engulfing the entire group, the Black Shark procurement hung in suspension, to be formally rejected by the government in 2016.
This means that the advanced submarine has been commissioned without its most potent weapon. A substitute has been the older generation SUT torpedo that India operates from its Shishumar (HDW) class. A fresh process is on to select a new torpedo.
The big leak
The last controversy to engulf the project was a massive breach of data that its French manufacturer faced in August 2016. The leak—thousands of pages of blueprints and plans published by an Australian newspaper—caused an uproar as it contained information on noise levels, sonar characteristics, endurance and manoeuvrability and combat system information, among others.
An assessment by the Navy, however, played down the breach, saying that 90 per cent of the information was commercially available and the most critical data on weapon systems was not leaked.

The minefields & torpedoes INS Kalvari skirted before Modi commissioning


Rain Man
Dec 1, 2017
INS Kalvari: India’s first Scorpene-class submarine commissioned by PM Modi; how it gives Navy tactical edge

INS Kalvari is India's first Scorpene-class submarine and will be commissioned into the Indian Navy by PM Narendra Modi today. Kalvari, packing a potent punch, is the first in the lot of six Scorpene-class submarines that are being manufactured by homegrown PSU Mazagaon Docks Limited (MDL) in collaboration with French defence major DCNS.

By: Smriti Jain | New Delhi | Updated: December 14, 2017 9:21 AM


INS Kalvari is India’s first Scorpene-class submarine and will be commissioned into the Indian Navy by PM Narendra Modi today.

INS Kalvari is India’s first Scorpene-class submarine and will be commissioned into the Indian Navy by PM Narendra Modi today. Kalvari, packing a potent punch, is the first in the lot of six Scorpene-class submarines that are being manufactured by homegrown PSU Mazagaon Docks Limited (MDL) in collaboration with French defence major DCNS. Regarded as the “most potent platform” to have been made in India, INS Kalvari, a diesel electric submarine, is a definite boost to Indian Navy’s surveillance and attack capabilities at a time when ties with China and Pakistan continue to be under pressure. INS Kalvari, according to the Ministry of Defence, has the capability of undertaking offensive operations “spanning the entire spectrum of maritime warfare”.

At a time when Indian Navy is down to a dozen submarines, the importance of Kalvari’s commissioning cannot be understated. The Kalvari, having been manufactured in India under Project 75, also gives the defence industry the capability of building more advanced submarines in the future. According to Abhijit Singh, the Head of Maritime Policy Initiative at ORF, Kalvari will give the Indian Navy a much-needed tactical edge. “Scorpene-class subramines are definitely better than the Kilo-class ones that we have right now. The submarine has precision strike capabilities and is capable of operating in shallow waters as well. It is also a very silent submarine, giving it a big edge in the waters,” Singh tells FE Online. “Add to that the fact that these have been made in India, even if with collaboration with a foreign firm. This means that for future, India will be able to make world-class submarines without help,” he adds.

INS KalvariFacts:
Class: Scorpene
Length: 67.5 m
Height: 12.3 m
Motto: Ever Onward
Crest: Tiger Shark

INS Kalvari is 67.5 metres long and has a height of 12.3 metres. The submarine “embodies cutting-edge technology and compares favourably with the best in the world”. “The hull form, the fin and the hydroplanes are specifically designed to produce minimum underwater resistance. The 360 battery cells (each weighing 750 kg) power the extremely silent permanently magnetised propulsion motor. The stealth is further enhanced through the mounting of equipment inside the pressure hull on shock absorbing cradles,” says the Ministry of Defence. The submarine is equipped with advanced weapons and sensors that are integrated into the submarine tactical integrated combat system. The sonar suite is low-frequency analysis and ranging capable, hence enabling long-range detection and classification. The submarine can engage the enemy by utilising either the sea skimming SM 39 EXOCET missiles or the heavyweight wire guided surface and underwater target torpedoes. The submarine is fitted with mobile C303/S anti-torpedo decoys.

“The submarine’s attack and search periscopes are equipped with infrared/low light level cameras and laser range finders. Kalvari has two 1250 kW MAN diesel engines for rapidly charging batteries. The submarine boasts of a highly advanced combat management system and a sophisticated integrated platform management system,” adds the Ministry of Defence. The submarine’s crest depicts a Kalvari, which is a tiger shark in Malayalam. The submarine’s motto is “Ever Onward”.

INS Kalvari has undergone extensive sea-trials over the past year-and-a-half and has successfully test-fired anti-ship missiles and torpedos. These precision-strike weapons give Kalvari and as a result the Indian Navy, a tactical advantage and leg-up in the Indian Ocean region. All six ‘Make in India’ Scorpene-class submarines will be equipped with torpedos and anti-ship missiles that have a proven track record in combat. According to the Indian Navy, the missiles will provide INS Kalvari with the “ability to neutralise surface threats at extended ranges”.

INS Kalvari: India’s first Scorpene-class submarine commissioned by PM Modi; how it gives Navy tactical edge
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Staff member
Nov 30, 2017
From trishul-trident - PSK Blog
INS Kalvari S-21 SSK's On-Board Systems & Fitments

INS Kalvari CM-2000 Scorpene SSK.jpg
INS Kalvari S-21 SSK-3.jpg
INS Kalvari S-21 SSK-2.jpg
ECA Static Converter-1.jpg
ECA Static Converter-2.jpg
ECA Steering Console.jpg
SUBTICS CMS Consoles.jpg
Scorpene SSK's Electronic Chart.jpg

A unique feature of each of the Indian Navy’s six Scorpene SSKs is an on-board tactical situational awareness display console (above) of the kind normally found on SSNs, SSGNs and SSBNs. On this single console, the SSK’s Commanding Officer can view overlaid electronic navigation charts, the tactical situation picture, as well as a THALES-provided track table interface to the US Naval Research Laboratory-developed display and analysis tool set, called SIMDIS. The SIMDIS is a set of GOTS software tools in use to support 2-D and 3-D analysis and visualization of the undersea battlefield. SIMDIS allows an integrated real-time view of both time-space position information (TSPI) and telemetry data, and it also provides an intuitive view of complex system interactions before, during and after an event.

TRISHUL: INS Kalvari S-21 SSK's On-Board Systems & Fitments

rest continued in next part


Dec 2, 2017
INS Kalvari’s Commissioning Marks The Revival Of Diesel-Electric Submarine Construction In India
Saurav Jha
December 14, 2017

The Indian Navy’s (IN’s) first Scorpene class submarine, the INS Kalvari, was commissioned earlier today at the Naval Dockyard in Mumbai in a ceremony presided over by Prime Minister Narendra Modi. While construction began in 2006, INS Kalvari headed out for sea trials only in 2016 and there were a few more minor delays before the boat was officially inducted. The overall programme, called Project 75, to construct six Scorpene submarines domestically with transfer of technology from France’s Naval Group at a cost of Rs 23,562 crores, has been dogged by various controversies over the years, not the least of which was the reported ‘leak’ of some 22,400 documents purportedly related to the operational characteristics of the IN’s Scorpenes. Nonetheless, INS Kalvari’s commissioning does mark a revival of the practice of ‘diesel-electric submarine’ (SSK) construction in India, given that the last SSK built in India by Mazagon Dockyard Limited (MDL), still India’s only shipyard that actually builds SSKs, was commissioned in 1994 and that too with a different foreign collaborator.

Indeed, the delays in construction are reflective of the time taken by Indian project managers and workmen to imbibe French submarine design and construction methodologies, which though in tune with global best practices in terms of modularity and integrated hull outfitting, do have their peculiarities. Moreover, though indigenous content in the Scorpene class boats is only between 30-40 percent, the project has helped enlarge the local vendor base capable of producing marine grade equipment. The second unit of the now Kalvari Class (since INS Kalvari has been commissioned), the ‘Khanderi’, was launched in January 2017 and is currently undergoing sea trials. ‘Karanj’, which is the third boat of the class is likely to be launched in the next few months. The remaining three boats of the class are presently in various stages of construction and the last boat is expected to be delivered by the end of 2020. With Project 75 clearly out of the stovepipe and into the light, it is time to take a closer look at some of the features of INS Kalvari and her sisters.

The build story

Image: Indian PM Narendra Modi aboard INS Kalvari during this morning’s commissioning ceremony. Source: PIB

The overall length of INS Kalvari is 67.5 metres (m) and its height is 12.3 m. Being derived from Naval Group’s Scorpene-2000 offering, this boat has a submerged displacement of 1585 tonnes. Its construction began in 2006 at MDL Yard 11875, with the completed hull being hauled out from dry dock on a submarine launch pontoon in April 2015 and the boat put out to sea for the first time, only last May. The submarine was delivered to the IN in September this year prior to today’s commissioning.

So over a decade has gone into getting the first Scorpene ready for service, even as MDL learnt the principles of contemporary submarine construction, with a French accent. INS Kalvari was built using a modular approach, whereby five separate sections (all built in parallel) were welded together in a process known as the ‘boot together’. (Of course, strictly speaking the boot together refers to the last two sections of the submarine being joined together which have been formed out of the original five). Now, the building of the submarine itself started with the fabrication of ring frames which was followed by plate forming. These were then assembled into sub-sections that went into the five separate sections used for the ‘boot together’. Even as the sections were being fabricated, the outfitting of shock-resistant cradles with mission equipment was being taken forward in parallel. The outfitted cradles were then embarked into the five major sections, which were then lowered onto the dry dock pontoon mentioned earlier, prior to the ‘boot together’. INS Kalvari’s ‘boot together’ happened in July 2014.

Hull and more

Image: INS Kalvari at its commissioning ceremony
Now the structural material used for the pressure hull of this submarine is a high-yield stress-specific micro-alloy steel called ‘80 HLES’. As such, 80 HLES is used extensively in French submarine construction and has characteristics such as very high mechanical strength while retaining the ability to be cut, formed and welded together using standard methods.

The high yield and tensile strength of this steel allows the pressure hull to be lighter than it would be with a material that is less tough, thereby facilitating the carriage of more fuel and ammunition on board. The use of 80 HLES also makes the hull capable of withstanding high hyrdrostatic force levels, thereby enabling deeper dives, which is turn leads to greater stealth in operations. The ‘test depth’ of INS Kalvari is likely to be 350 m. As an aside, HLES is a classification used in Europe and is basically equivalent to the HY 100 steel used in the United States (US) for naval construction. Arcelor Mittal’s subsidiary Industeel is a known supplier of 80 HLES.

INS Kalvari’s albacore bow shape, propeller scheme, overall hull form which has fewer appendages (i.e forward and aft control surfaces) than legacy forms, and the appendages themselves, have all been specifically designed to minimize hydrodynamic resistance leading to a lowering of radiated noise levels. The positioning of equipment on suspended shock-resistant cradles by using elastic mountings also contributes significantly to emitted noise reduction. In fact, the loudest pieces of equipment are put on double-elastic mountings. As such, it can be said that INS Kalvari boasts a greater degree of acoustic discretion than other submarines currently operating in the Indian Ocean Region (IOR).

The Kalvari’s low-noise signature and advanced hydrodynamics confers upon it the characteristics necessary to perform a range of missions in the IOR by utilizing an advanced sensor and weapon suite, some details of which we shall see later. The submarine, besides being able to conduct standard missions such as, mine-laying, intelligence, surveillance and reconnaissance (ISR), anti-submarine warfare (ASW) and anti-surface warfare (ASuW), in both open and closed sea conditions, will also be able to insert special forces (SF) troops via littoral waters. Being highly automated, INS Kalvari has a complement of only 31 personnel, leaving enough ‘space’ for six SF troops and their equipment.

INS Kalvari also has two refuge compartments which can be used to rescue personnel in the event of an accident, by using the two deep-submergence rescue vehicles that the IN is procuring from Britain. It also has a cofferdam as an added safety feature.

While underwater, the Kalvari’s stealthy mass is propelled due to the power supplied by 360 lead acid batteries, each weighing some 750 kg, to a 13-phase permanent magnet synchronous motor developed by Naval Group-AREVA-Jeumont , which turns the propeller. The quiet synchronous motor is itself mounted on a shock-resistant cradle. The batteries are charged by two 1250 kW MAN diesel engines. Of note is the fact that at the top of the hull immediately above the diesel engines is a so-called ‘Dutch Breach’ that facilitates easy removal of these engines for maintenance and overhaul. This propulsive arrangement should give the Kalvari Class boats a top speed of 20 knots per hour underwater and a submerged endurance of six days or the ability to traverse 1,020 km underwater without the need to surface.

As we have written before, once INS Kalvari is due for its first major refit, an air-independent propulsion (AIP) system developed by the Naval Materials Research Laboratory, which is a part of the Defence Research & Development Organization (DRDO) will be incorporated into the hull of this submarine by first cutting it open. This will subsequently be done to the rest of the Kalvari Class boats as well, once they come in for their first refits.

The quiet hull and propulsive machinery provide INS Kalvari a stealthy base, as it were, to carry out a wide range of missions whose efficacy is contingent upon the performance of the boat’s sensor suite and navigation set up. The submarine’s sonar suite is the Thales supplied TSM 2022 MkIII, which according to the manufacturer is capable of long range low-frequency (LF) detection, high frequency (HF) detection, LF minimum detectable velocity tracking, LF mine avoidance, VHF shadow classification, HF and VHF route survey as well as HF moored mine classification.

Scorpenes sold to a user other than the IN are equipped with EDO Reconnaissance Systems and the AR-900 electronic support measures/direction-finding (ESM/DF) system from Harris. It cannot be confirmed whether INS Kalvari has the same fit and it is possible that INS Kalvari uses French sourced equipment for these purposes. INS Kalvari does have two Sagem supplied optronic masts, with one meant for attack and the other for surveillance. These are equipped with Infrared/ low-light level cameras and laser range finders.

INS Kalvari has a high accuracy ring-laser gyroscope (RLG) at the core of its integrated navigation system which also combines data from multi-constellation satellite updates, the boat’s log, depth measurement devices and its trim / list monitoring system. INS Kalvari has on-board sensors for recording seawater density and temperature as well as its own acoustic signature in the environment it’ll operate in. Going by standard IN practice, it can be surmised that INS Kalvari should be able to receive very low frequency (VLF) messages via a trailing antenna as well as encrypted burst communications when surfaced.

Ready for combat
The various sensors on board INS Kalvari and any data received by it from external sources will all feed its combat management system (CMS) called the Submarine Tactical Integrated Combat System (SUBTICS). SUBTICS, reportedly ‘has six multifunction common consoles and a centrally situated tactical table, which is collocated with the platform-control facilities’. It has a command and tactical data handling system and a weapon control system which it integrates with the boat’s suite of sensors and navigation set up.

Once informed by its ‘sources’, SUBTICS can choose to engage enemy targets with INS Kalvari’s weapons suite which includes the sea skimming SM-39 Exocet anti-ship missile (AshM) with a range of 150 km and a payload of 150 kg and the heavyweight 533 mm AEG-SUT Mod 1 torpedoes, which are already in use with the IN’s Shishumar Class submarines and will be an interim weapon for the Kalvari Class boats. These weapons will be released via INS Kalvari’s six Weapon Launching Tubes (WLT), which can be reloaded at sea. INS Kalvari is also kitted out with the C303/S anti-torpedo countermeasure system for self-defence.

Prospects for Indigenization
Though the indigenous content (IC) level is INS Kalvari is not high due to contract stipulations and other issues, Project 75 has nevertheless drawn upon Indian industry to source items such as weld consumables, ventilation coamings, cables, anechoic tiles, GRP casing panels, the lead acid main batteries etc. Moreover, equipment such as the thrust block, hydraulic blocks, hydraulic plungers and hydroplanes were machined in India with material imported from abroad. The IN believes that given its domestic vendor base, equipment such as different types of pumps, AC plants, accumulators, various types of filters and the demineralised water plant could all be indigenized progressively.

Greater IC levels are intended for any follow-on order for three more Kalvari Class boats as is being reportedly mused by New Delhi. However, systems such as CMS and optronic masts are likely to be imported for any follow-on units. The current RLG used on board could in theory be replaced by one developed by DRDO, which recently supplied the IN with a high accuracy RLG for surface ships. DRDO’s Research Center Imarat is known to be developing high accuracy mirror-based RLGs that can be used on-board submarines.

Beyond the use of indigenous equipment in Project 75, is the development of human resources that has taken place as a result of the programme. MDL now has people who are well familiarized with the construction process, documentation and quality/assurance procedures followed by the French while building SSKs such as the Scorpene. Personnel from both MDL and the IN have gained considerable expertise and knowhow with respect to contemporary welding craft and technology, test procedures and acceptance criteria. Thanks to this build programme, India now has a number of welders qualified in major metal arc welding techniques used to build pressure hulls.

Obviously, fabrication pedigree through Project 75 did not come overnight. For instance, there were setbacks related to even cutting and rolling the steel used to fabricate hull sections. But today, rejection rates have become quite low as a result of learning by doing. Packaging equipment on board the major sections of INS Kalvari is no mean task. Nor is the issue of ‘connecting’ systems together via some 60 km of cabling and a further 11 km of piping. Beyond MDL, outsourcing to private vendors has also led to a qualitative improvement in their build standards due to the stringent tolerances demanded by the program.

Overall INS Kalvari’s commissioning marks a new day for SSK construction in India. The learnings are likely to be ported to Project 75I, which envisions the domestic construction of six more SSKs of contemporary design with foreign collaboration, possibly by a yard other than MDL. Meanwhile, MDL says that its hull fabrication unit is fully oiled awaiting follow-on orders.

INS Kalvari's Commissioning Marks The Revival Of Diesel-Electric Submarine Construction In India | Delhi Defence Review

A Person

Senior member
Dec 1, 2017
A Place
This is indeed a great day for India. However, I just have one nagging worry- The Scorpene data leak. Hope the Navy has done all that was needed to mitigate the effects of that.
Most of the leaked documents are not very highly classified -- it's the information that is sent to countries issuing RFPs for the Scorpene. Furthermore, it corresponds to a paper submarine -- it's the projection made for the Scorpene design before it was actually built. It's not the specifications observed from real submarines. And lastly it corresponds to a baseline standard, not taking into account any customer-requested modification. These reasons are why the Indian Navy, after reviewing the situation, declared it was not an operational concern.


Staff member
Nov 30, 2017
From the same Tishul
France’s Direction Générale de l’Armement (DGA) has mandated that the F-21 HWT will equip all French Navy nuclear submarines. The F-21 has also been ordered by the Brazilian Navy. Naval Group has developed an important component for safe deployment: an energy pack based on an aluminium/silver oxide electric battery that needs seawater for activation—an element unlikely to be found in the submarine. To meet submarine safety requirements, the F-21 will be launched by a technique in which it is pushed out of the boat by a piston (rammer), after which a valve in the torpedo opens and lets seawater into the battery to activate it. The battery provides high energy density, and is sufficiently compact that the overall length of the F-21 HWT—6 metres (19.6 feet) long with a 21-inch (533mm) diameter—is compatible with legacy launchers. One problem with competitive torpedoes that are equipped with older-generation batteries is that to achieve the energy for their missions and countermeasures, they need long batteries, which add so much to their length that they no longer fit into launchers. The torpedo must also have enough energy left once it has reached its target to attack and sink high-value targets such as aircraft carriers and frigates. This explains the importance of the primary battery as the energy source. The UK, Russia, US and Sweden have chosen thermal systems as their energy source. France specified the electric system because it is safe and silent. In underwater missions, silence is of the utmost importance to avoid detection by the enemy. This system enables a totally silent attack.

F-21 HWT-1.jpg
F-21 HWT-2.jpg

The F-21 is digital and operates in depths of 15-500 metres, which means it can be used in littoral and blue-water operations. In shallow waters there are “parasite” sounds that confuse torpedoes, which home in on targets acoustically. The F-21 treats the sound signals digitally with the same up-to-date processing as in modern warship sonars, which enables the F-21 to largely overcome this difficulty. The F-21 weighs 1.2 tons, has a range of 50km, speed of 50 Knots., and 1-hour endurance. It can attack multiple targets and has extended fibre-optic wire guidance that is resistant to most countermeasures. The warhead contains PBX B2211, a high-impulse, high-bubble-energy, insensitive explosive that conforms to NATO’s STANAG-4439 and France’s MURAT (Munitions a Risques Attenues) standards. The torpedo uses an all-electric “fuse-and-slapper” detonation technology. Primarily used in guided-missiles, the plasma-based slapper system is more stable and safer than the conventional electro-mechanical detonation systems in most torpedoes. The torpedo configuration can be changed from a weapon to a training device by just puting an exercise section on it instead of an explosive one. One can also change the primary battery, providing it with a secondary battery based on lithium-ion technology, which is reusable a great number of times.