Indian Nuclear Attack Submarine (Project 77) - Updates & Discussions

[gearedcombustor]

I think, you are confusing terms. He is referring to enrichment of the fuel not efficiency.

US study of reactor and fuel types to enable naval reactors to shift from HEU fuel

Alan Kuperman, Frank von Hippel In February 2020, the US Department of Energy's office of Defense Nuclear Nonproliferation released its report, Initial Evaluation of Fuel-Reactor Concepts for Advanced LEU Fuel Development, a screening study for potential fuel and reactor types...

fissilematerials.org

He actually meant power density but used the word efficiency.

Enrichment doesn't affect efficiency at all.

It affects power density but the advantages of higher power density (reactor size comparative) are negligible due limitations I mention below.

Power density (fuel pin size) is not a useful parameter at all as long as you are not the fuel rod designer.

--Subquoting my responses from another forum

Yes Power density is the right word. Efficiency doesn't change - HEU or LEU or even 100% U235 or Pu or any fuel won't change this fact. Fuel enrichment is used to enhance the maximum allowable fuel burnup not the thermal efficiency.

LEU/HEU generally contains U238 which produces Plutonium while U235 fission produces most of the energy. The maximum permissible limit of side reactions like Plutonium, Neptunium being generated through the neutron absorption by U238 is the Maximum allowable fuel burnup. Exceeding the burnup will cause increase in uncharacterised fission reactions that will melt the fuel rods or create too much radioactivity that exceeds shielding limits or damages the RPV. Moving from LEU to HEU allows you to reduce these unnecessary side reactions and allows you to increase your Maximum fuel burnup before you need to refuel.

Humans only extract small percentage of the fission energy from U235 due to these limits. HEU raises that limit but doesn't change the transient energy release for the chain reaction as long as the core doesn't go supercritical. Raising transient energy release will require increasing neutron flux i.e the rate of the chain reaction which means you will go Chernobyl/Hiroshima beyond a limit. The flux limit is the same even if it HEU or LEU.

Enrichment only affects your burnup not the per atom heat generation.

Enrichment doesn't affect thermal efficiency.

Enrichment doesn't affect the coolant's reactor outlet temperature. It's only a function of pressure and coolant void coefficient.

i.e. enrichment only affects your refueling frequency not your efficiency

expand...Power density affects the size of your reactor and control systems. Going too high on your power density is not recommended either - This will require very miniaturised and very sensitive control rods but there is still a lower limit on the reactor vessel size as you cannot put the fuel rods too close to avoid going critical at idle.



The American reactors are still probably the same size as the Russian ones as at such high 90%s enrichment you will have to fill the reactor with dummy rods to avoid localised criticality and have fast flowing coolant to quickly take away heat so the fuel rods won't melt. The lesser enrichment reactors are much safer.

Balancing safety with your refueling frequency also becomes important.

Such dreams of high power density might even give ideas to bring back the lead cooled fast reactors like the Alfa. Sodium Fast breeders are too flammable for mil application.

 

[Tatvamasi]

https://twitter.com/x/status/1462074029104254977

 

[Arctic Wolf]

Janes reports that the indigenous SSN programme will get CCS approval before mid-2022. Initially, $6.67 billion will be sanctioned for 3 6,000-ton SSNs.

India to approve plans for six-boat nuclear submarine fleet

India's federal government is expected to approve funding for the Indian Navy's (IN's) amended 30-year submarine building plan, first sanctioned in 1999, which will now...

www.janes.com

 

[RISING SUN]

India’s 1st Nuclear Submarine INS Chakra Was A Highly Classified Project; Crew Recount Gruelling Russian Experience​

As the Indian Navy continues to bolster its submarine fleet, two distinguished Navy veterans recount their experiences with India’s first nuclear submarine, INS Chakra.


Addressing the press on the eve of 50th Navy Day, on December 3, Indian Navy chief Admiral R. Hari Kumar said, “Modernization of our submarine arm is underway. We have commissioned four of the six boats of the indigenous Scorpene-class submarines. This year, we commissioned the third boat, Karanj in March and the fourth boat, Vela in November. The fifth boat Vagir has also been launched.”


The EurAsian Times spoke to two distinguished veterans from the Indian Navy’s silent arm, who recounted their journey in the elite service including their time onboard INS Chakra.

Indian Navy chief, Admiral R. Hari Kumar.
INS Chakra was taken on lease during the end of the Cold War. The Indian Navy had received a Charlie-class nuclear cruise missile submarine for a decade from the erstwhile Soviet Union after signing an agreement in July 1987. This was the first time a nation had leased out a nuclear submarine.

A Soviet Account​

Soviet submariner Alexander Ivavovich Terenov, who served as the Commanding Officer of the SSGN K-43 penned down his experiences while onboard INS Chakra in his book, Under three flags – The Saga of the submarine Cruiser K-43/Chakra. He chronicled “many incidents of submarine malfunction”.


The outboard pipes and equipment corroded fast due to the high air temperature, humidity, and salinity. The main suction line was not renewed during the last refit in the Soviet Union which caused flooding and fire. A major emergency at sea was experienced and it took months to repair the submarine.

An aerial view of the Soviet-built INS Chakra. (Wikipedia)
“Other issues included poor documentation, false data, and poor discipline in the supply of spares from the Soviet Union. In one instance, the Indian Navy refused to take supplies of the batteries due to their poor condition. The batteries had to be set right in India itself,” Terenov noted.


Terenov was summoned to Moscow in 1990, at the end of the third year of the lease and was told to let Indians know that the lease would not be extended. On December 17, the submarine set sail and reached Vladivostok on January 5.


Once in Russia, the submarine was sent to Kamchatka for decommissioning. “During its operational life, the submarine had traveled 72,000 miles, the main power plant had operated for 430 days, fired five missiles and 42 torpedoes,” said Joseph P Chacko, author of Foxtrot to Arihant: The Story of Indian Navy’s Submarine Arm’.

INS Chakra: ‘The Pioneer & Her Men’​

Commodore Arun Kumar, NM (Retd), author of S71 INS Chakra – The Pioneer and her Men had an eventful naval career even before his appointment onboard INS Chakra.


A series of courses and demonstrations of professional acumen led the Indian Navy to consider him as the right person for the top-secret assignment. This included his appointment as Navigating Officer onboard the erstwhile INS Vela laid the foundation for his journey with INS Chakra.


Commodore Kumar recounted his journey: “This offered me a great opportunity to navigate the boat from Bombay to Vladivostok (VV) where she was to undergo a medium refit for two years. However, I returned soon after docking her in VV. After that, I served on the Staff of Capt SM 9 in Bombay till Sep 81 and on Staff of Capt SM8 at Visakhapatnam till Aug 1982, whence I was selected for the training for nuclear submarine training at VV for 30 months from Oct 1983-Apr 1986.

Indian Navy Commodore Arun Kumar (right) in Russia (Soviet Union). — By Special Arrangement
“The training in Vladivostok, I dare say, was of the highest standards. It was all in the Russian language which posed a greater challenge as we learned complex disciplines such as nuclear physics, nuclear reaction and the hardware associated with the reactor and propulsion systems, radiation safety and waste management apart from command and control of operating a cruise missile capable nuclear-powered submarine (SSGN) in the Russian language.


“I was part of the command team as the First Lieutenant (In the rank of Lt. Cdr). The training was intense and comprised 18 months of language (4) and specialist courses (14) and 12 months of sea training. On successful completion, I returned to India in April 1986.


“The time available on return enabled me to finish my mandatory sea time as an XO [Executive Officer] of a submarine on INS Vagli from May 1986 to April 1987, when I was attached to INS Virbahu awaiting departure to Vladivostok for commissioning the first nuclear submarine of the Indian Navy.


“I was to be the First LT and the Operations Officer of the boat. In the meantime, in June 1987, I got promoted to the rank of Cdr. I utilized the time at Virbahu to write down the Standing Orders and Standard Operating Procedures for the nuclear submarine, a subject new to us.


“The Commissioning crew left for Vladivostok on 7 August 1987. After refresher training and practical operations both at sea and in harbor, we commissioned the submarine named INS Chakra on 5 Jan 1988, on a three-year lease to the Indian Navy. It was truly a historic occasion, and I was privileged and honored to be part of it.


“After a maiden passage of 18 days, the submarine arrived at Vizag on 3 Feb 1988 and was received by Mr. Rajiv Gandhi, then Prime Minister of India.


It was once again an honor befitting the occasion. The Indian Navy had graduated from operating conventional subs to a nuclear-powered one in just 20 years since the inception of the submarine arm in December 1967, a feat unparalleled.


“After the first operating cycle in 1988, I was deputed for my Submarine Commanding Officer’s Qualifying Course, which I completed in December 1988, standing first in merit, and was awarded the coveted CNS trophy for the same. For the next 18 months, I was in command of a Kilo Class boat INS Sindhuraj and joined Chakra again in June 1990 as the XO or the second in command.


“The third operational cycle was probably the most effective in terms of time spent at sea. In Dec 1990, orders were received to head back for VV to return the boat on completion of the lease on 4 Jan 1991. We set sail from Vizag on 15 Dec 1990 and arrived at VV in the forenoon of 4 Jan 1991.


The boat was decommissioned on January 5, 1991, and handed back to the Soviet Navy. His experience onboard INS Chakra helped him cement a flourishing career in the Indian Navy, holding some of the organization’s most coveted appointments.

INS Chakra. (by special arrangement)
Commodore Randhir Singh (Retd) who served as the First Lieutenant of the training crew recounted his experience onboard INS Chakra: “To have been chosen for India’s first Nuclear submarine was precious enough! From 1983 to 1986, we went through a rare learning and grueling phase. I was privileged to have been trained by the pioneers in the field of nuclear propulsion and submarining. Russia handpicked each professor who taught us. We were indeed fortunate to have learned from such stalwarts. They would fly down from Moscow, just for one lecture!


“So, in the distant land of Vladivostok, we had to keep everything under tight wraps. Being a highly classified project, all activities and communications were restricted or monitored. Nonetheless, the shore and sea training went well, and our Russian instructors were proud of us at the end,” Cmde. Singh concluded before signing off.

The Covert Nature Of Training​

Chacko described the highly sensitive nature of INS Chakra’s crew training and operations: “The training imparted to the Indian Navy personnel on the nuclear submarine was thorough. A secret library was made available to the Indian Navy personnel where they could only take notes and return the book to the shelf before leaving.


“The naval personnel gathered as much information as possible as they knew the books cannot be referred after the training was over. During the practical training, the operations of the nuclear submarine were progressively handed over to the Indian crew till the entire running of the submarine was done by an all Indian Navy crew and the Soviets naval personnel as observers.

The handing over ceremony of INS Chakra. (by special arrangement)
“There was a time gap of many months between the training and the actual handover of the boat. The Indian crew had to be given a refresher course before the handing over. The trust was such that the Soviets handed over the complete control of the nuclear submarine to the Indian Naval personnel after the refresher course.


“The confidence among the Indian navy personnel was so high that the submarine sailed from Vladivostok to Visakhapatnam, about 10,300 km, operated and commanded by the Indian crew. The Russians, who were called the specialists, had no role during the operations of INS Chakra while in the Indian navy service,” the naval historian concluded before signing off.

India’s 1st Nuclear Submarine INS Chakra Was A Highly Classified Project; Crew Recount Gruelling Russian Experience

INS Chakra.: As Indian Navy continues to bolster submarine fleet, Navy veterans recount India’s first nuclear submarine from Russia

eurasiantimes.com

 

[Sathya]

France Set To Offer Barracuda Nuclear Submarines To India

French Defence Minister to visit New Delhi for talks with Rajnath Singh on December 17

15th December, 2021
by Vishal Thapar

France is set to dramatically scale up defence cooperation with India by putting the Barracuda nuclear attack submarine on the table. French Defence Minister Florence Parly is expected to broach the offer for the Barracudas with a Make in India element during her visit to India on December 17 and 18, BW Businessworld has learnt from highly-placed sources. The French Minister is slated to have talks with her Indian counterpart Rajnath Singh in New Delhi on December 17.

This is the most significant offer of military equipment to India and could give the Indian Navy formidable sea denial capability in the Indian Ocean Region and provide it the sea legs to exercise a credible military presence in the Indo-Pacific Region. Nuclear submarine technology is regarded as the crown jewel of military capability.

“The French Defence Minister’s visit will have a heavy maritime focus,” informed sources confirmed to this reporter.

Coming close on the heels of the Rafale fighter aircraft deal, this reported French offer to provide India the knowhow to make nuclear submarines has the potential to establish France as India’s pre-eminent Defence partner, a position traditionally enjoyed by Russia.

This is the first time that a nuclear-powered attack submarine technology would be offered to India. In the past, Russia and the erstwhile Soviet Union have on two occasions leased nuclear-powered attack submarines (SSN) to India. India has also signed a reported $3 Billion deal in 2019 for the lease of another SSN of the Akula class to the Indian Navy, making it the only navy other than those of the P5 countries to have operated a nuclear attack submarine.

The Barracuda class submarine is nuclear-powered but not nuclear armed. An SSN like the Barracuda is nonetheless the most formidable sea denial weapon. This submarine, while remaining submerged for extended durations, has a powerful land attack capability with the 1,000-km-range Scalp Naval cruise missile. The time between refueling is a reported 10 years.

Observers reckon that the door for the French offer of nuclear submarines to India opened up after the deal to provide American and British nuclear submarine knowhow to Australia upon the forging of the AUKUS grouping to deter China. France is also smarting from the Australian cancellation of a mega deal for 12 conventional submarines while accepting the American offer under the AUKUS umbrella.

But acquiring deep technology for SSNs has been a priority for India for many years. The indigenous programme for six SSNs is still in the design stage. The offer for the Barracuda is the consequence of regular deep consultations with France to deepen military cooperation. In October, the 5th session of the India-Franco Maritime Cooperation dialogue was held in Paris to carry forward discussions between Prime Minister Narendra Modi and French President Emmanuel Macron.

Defence cooperation was reportedly on top of the agenda during the 35th Indo-French Strategic Dialogue between National Security Advisor Ajit Doval and his French counterpart Emmanuel Bonne in Paris in November. The two sides have also been interacting deeply at a number of other fora, and France has repeatedly declared India as the cornerstone of its strategy in the Indo-Pacific.

The Barracuda submarine is produced by the Naval Group, which is currently engaged in delivering the contract to build six Scorpene class diesel-electric submarines at Mazagon Dock Shipbuilders (MDL), Mumbai, for the Indian Navy.

If the Barracuda offer gains momentum, it is expected to have repercussions for the ongoing $5.7 billion programme to build a new line of six diesel-electric submarines for the Indian Navy under Project 75 (I), which is already struggling with a de facto single vendor situation.

Recently, BW Businessworld reported exclusively that of the two foreign OEMs which meet the Project 75 (I) tender requirement for a proven fuel cell-based Air Independent Propulsion System, the German TKMS is giving indications of a pullout from the competition, leaving only the Daewoo KSS-III of South Korea in the fray. In this situation, both the shortlisted Indian Strategic Partner hopefuls MDL and L&T would be compelled to submit rival bids in collaboration with the same foreign partner, effectively reducing it to a single horse race with two jockeys.

The Barracuda offer could potentially subsume Project 75 (I), informed observers reckon.

The French Defence Minister is also expected to reiterate the pitch for the Rafale in connection with an upcoming Indian tender for 114 Multi Role Fighter Aircraft (MRFA).

France Set To Offer Barracuda Nuclear Submarines To India

Naval Recognition has also picked it up :

France may offer Barracuda class submarines to India

@Picdelamirand-oil @Bon Plan

 

[Picdelamirand-oil]

France Set To Offer Barracuda Nuclear Submarines To India

French Defence Minister to visit New Delhi for talks with Rajnath Singh on December 17

15th December, 2021
by Vishal Thapar
View attachment 22073

France is set to dramatically scale up defence cooperation with India by putting the Barracuda nuclear attack submarine on the table. French Defence Minister Florence Parly is expected to broach the offer for the Barracudas with a Make in India element during her visit to India on December 17 and 18, BW Businessworld has learnt from highly-placed sources. The French Minister is slated to have talks with her Indian counterpart Rajnath Singh in New Delhi on December 17.

This is the most significant offer of military equipment to India and could give the Indian Navy formidable sea denial capability in the Indian Ocean Region and provide it the sea legs to exercise a credible military presence in the Indo-Pacific Region. Nuclear submarine technology is regarded as the crown jewel of military capability.

“The French Defence Minister’s visit will have a heavy maritime focus,” informed sources confirmed to this reporter.

Coming close on the heels of the Rafale fighter aircraft deal, this reported French offer to provide India the knowhow to make nuclear submarines has the potential to establish France as India’s pre-eminent Defence partner, a position traditionally enjoyed by Russia.

This is the first time that a nuclear-powered attack submarine technology would be offered to India. In the past, Russia and the erstwhile Soviet Union have on two occasions leased nuclear-powered attack submarines (SSN) to India. India has also signed a reported $3 Billion deal in 2019 for the lease of another SSN of the Akula class to the Indian Navy, making it the only navy other than those of the P5 countries to have operated a nuclear attack submarine.

The Barracuda class submarine is nuclear-powered but not nuclear armed. An SSN like the Barracuda is nonetheless the most formidable sea denial weapon. This submarine, while remaining submerged for extended durations, has a powerful land attack capability with the 1,000-km-range Scalp Naval cruise missile. The time between refueling is a reported 10 years.

Observers reckon that the door for the French offer of nuclear submarines to India opened up after the deal to provide American and British nuclear submarine knowhow to Australia upon the forging of the AUKUS grouping to deter China. France is also smarting from the Australian cancellation of a mega deal for 12 conventional submarines while accepting the American offer under the AUKUS umbrella.

But acquiring deep technology for SSNs has been a priority for India for many years. The indigenous programme for six SSNs is still in the design stage. The offer for the Barracuda is the consequence of regular deep consultations with France to deepen military cooperation. In October, the 5th session of the India-Franco Maritime Cooperation dialogue was held in Paris to carry forward discussions between Prime Minister Narendra Modi and French President Emmanuel Macron.

Defence cooperation was reportedly on top of the agenda during the 35th Indo-French Strategic Dialogue between National Security Advisor Ajit Doval and his French counterpart Emmanuel Bonne in Paris in November. The two sides have also been interacting deeply at a number of other fora, and France has repeatedly declared India as the cornerstone of its strategy in the Indo-Pacific.

The Barracuda submarine is produced by the Naval Group, which is currently engaged in delivering the contract to build six Scorpene class diesel-electric submarines at Mazagon Dock Shipbuilders (MDL), Mumbai, for the Indian Navy.

If the Barracuda offer gains momentum, it is expected to have repercussions for the ongoing $5.7 billion programme to build a new line of six diesel-electric submarines for the Indian Navy under Project 75 (I), which is already struggling with a de facto single vendor situation.

Recently, BW Businessworld reported exclusively that of the two foreign OEMs which meet the Project 75 (I) tender requirement for a proven fuel cell-based Air Independent Propulsion System, the German TKMS is giving indications of a pullout from the competition, leaving only the Daewoo KSS-III of South Korea in the fray. In this situation, both the shortlisted Indian Strategic Partner hopefuls MDL and L&T would be compelled to submit rival bids in collaboration with the same foreign partner, effectively reducing it to a single horse race with two jockeys.

The Barracuda offer could potentially subsume Project 75 (I), informed observers reckon.

The French Defence Minister is also expected to reiterate the pitch for the Rafale in connection with an upcoming Indian tender for 114 Multi Role Fighter Aircraft (MRFA).

France Set To Offer Barracuda Nuclear Submarines To India

Naval Recognition has also picked it up :

France may offer Barracuda class submarines to India

@Picdelamirand-oil @Bon Plan

 

[randomradio]

France Set To Offer Barracuda Nuclear Submarines To India

French Defence Minister to visit New Delhi for talks with Rajnath Singh on December 17

15th December, 2021
by Vishal Thapar
View attachment 22073

France is set to dramatically scale up defence cooperation with India by putting the Barracuda nuclear attack submarine on the table. French Defence Minister Florence Parly is expected to broach the offer for the Barracudas with a Make in India element during her visit to India on December 17 and 18, BW Businessworld has learnt from highly-placed sources. The French Minister is slated to have talks with her Indian counterpart Rajnath Singh in New Delhi on December 17.

This is the most significant offer of military equipment to India and could give the Indian Navy formidable sea denial capability in the Indian Ocean Region and provide it the sea legs to exercise a credible military presence in the Indo-Pacific Region. Nuclear submarine technology is regarded as the crown jewel of military capability.

“The French Defence Minister’s visit will have a heavy maritime focus,” informed sources confirmed to this reporter.

Coming close on the heels of the Rafale fighter aircraft deal, this reported French offer to provide India the knowhow to make nuclear submarines has the potential to establish France as India’s pre-eminent Defence partner, a position traditionally enjoyed by Russia.

This is the first time that a nuclear-powered attack submarine technology would be offered to India. In the past, Russia and the erstwhile Soviet Union have on two occasions leased nuclear-powered attack submarines (SSN) to India. India has also signed a reported $3 Billion deal in 2019 for the lease of another SSN of the Akula class to the Indian Navy, making it the only navy other than those of the P5 countries to have operated a nuclear attack submarine.

The Barracuda class submarine is nuclear-powered but not nuclear armed. An SSN like the Barracuda is nonetheless the most formidable sea denial weapon. This submarine, while remaining submerged for extended durations, has a powerful land attack capability with the 1,000-km-range Scalp Naval cruise missile. The time between refueling is a reported 10 years.

Observers reckon that the door for the French offer of nuclear submarines to India opened up after the deal to provide American and British nuclear submarine knowhow to Australia upon the forging of the AUKUS grouping to deter China. France is also smarting from the Australian cancellation of a mega deal for 12 conventional submarines while accepting the American offer under the AUKUS umbrella.

But acquiring deep technology for SSNs has been a priority for India for many years. The indigenous programme for six SSNs is still in the design stage. The offer for the Barracuda is the consequence of regular deep consultations with France to deepen military cooperation. In October, the 5th session of the India-Franco Maritime Cooperation dialogue was held in Paris to carry forward discussions between Prime Minister Narendra Modi and French President Emmanuel Macron.

Defence cooperation was reportedly on top of the agenda during the 35th Indo-French Strategic Dialogue between National Security Advisor Ajit Doval and his French counterpart Emmanuel Bonne in Paris in November. The two sides have also been interacting deeply at a number of other fora, and France has repeatedly declared India as the cornerstone of its strategy in the Indo-Pacific.

The Barracuda submarine is produced by the Naval Group, which is currently engaged in delivering the contract to build six Scorpene class diesel-electric submarines at Mazagon Dock Shipbuilders (MDL), Mumbai, for the Indian Navy.

If the Barracuda offer gains momentum, it is expected to have repercussions for the ongoing $5.7 billion programme to build a new line of six diesel-electric submarines for the Indian Navy under Project 75 (I), which is already struggling with a de facto single vendor situation.

Recently, BW Businessworld reported exclusively that of the two foreign OEMs which meet the Project 75 (I) tender requirement for a proven fuel cell-based Air Independent Propulsion System, the German TKMS is giving indications of a pullout from the competition, leaving only the Daewoo KSS-III of South Korea in the fray. In this situation, both the shortlisted Indian Strategic Partner hopefuls MDL and L&T would be compelled to submit rival bids in collaboration with the same foreign partner, effectively reducing it to a single horse race with two jockeys.

The Barracuda offer could potentially subsume Project 75 (I), informed observers reckon.

The French Defence Minister is also expected to reiterate the pitch for the Rafale in connection with an upcoming Indian tender for 114 Multi Role Fighter Aircraft (MRFA).

France Set To Offer Barracuda Nuclear Submarines To India

Naval Recognition has also picked it up :

France may offer Barracuda class submarines to India

@Picdelamirand-oil @Bon Plan

Buying three of these is better than going for the P-75I. Pretty much the same price.

 

[Chain Smoker]

For further clarity

Main Motor Generator is the generator used to generate electricity for battery charging & onboard use from the main gear box driving the prop shaft connected to the nuclear steam turbine.

Reserve propulsion motor is the backup way to drive the shaft via the gearbox from the battery energy if the main reactor or the main plant fails/tripped.

It sounds like we are still Sticking with older gear box system instead of IEP @Gautam. @randomradio

 

[Gautam]

It sounds like we are still Sticking with older gear box system instead of IEP @Gautam. @randomradio

The PMSM electric motors that we are making for the upcoming SSNs are rated at 35 MWe. The 83 MWt CLWR-B1 reactor used on the Arihant class produces around 25 MWe. The reactor does not produce enough energy to max out the under-development motors. However, the 193 MWt CLWR-B2 reactor produces enough electrical power for the motors.

The power requirements for SSNs are different from that of the SSBNs. SSBNs usually cruise along at a slower speed in safer waters. SSNs regularly venture into hostile waters & often need to sprint out of trouble. The reactors we have developed so far are for the SSBNs not SSNs. So either of the 2 reactors would need to be modified to match the needs of the SSNs. We don't know for certain which reactor will go into the SSN program.

We have more experience with the B1 reactor. But using that would result in a slower cruise speed, thus requiring a mechanical gearbox to be used as back up. The mechanical gearbox would not be used all the time but would be used to boost the speed in case of eminent danger.

Using the B2 would mean higher cruise speeds. If we have some electrical power storage system onboard then we wont need mechanical gearboxes at all. Thus the submarine would be quieter even while sprinting.

Both options are on the table. Let's see where we go from here.

 

[Chain Smoker]

The PMSM electric motors that we are making for the upcoming SSNs are rated at 35 MWe. The 83 MWt CLWR-B1 reactor used on the Arihant class produces around 25 MWe. The reactor does not produce enough energy to max out the under-development motors. However, the 193 MWt CLWR-B2 reactor produces enough electrical power for the motors.

The power requirements for SSNs are different from that of the SSBNs. SSBNs usually cruise along at a slower speed in safer waters. SSNs regularly venture into hostile waters & often need to sprint out of trouble. The reactors we have developed so far are for the SSBNs not SSNs. So either of the 2 reactors would need to be modified to match the needs of the SSNs. We don't know for certain which reactor will go into the SSN program.

We have more experience with the B1 reactor. But using that would result in a slower cruise speed, thus requiring a mechanical gearbox to be used as back up. The mechanical gearbox would not be used all the time but would be used to boost the speed in case of eminent danger.

Using the B2 would mean higher cruise speeds. If we have some electrical power storage system onboard then we wont need mechanical gearboxes at all. Thus the submarine would be quieter even while sprinting.

Both options are on the table. Let's see where we go from here.

That's why there is confusion RPM are used in barracuda subs as a axillary motor in case of main motor failure.

What is the use of main motor generator when there is diesel generator unless we want to recharge the batteries even submerged.

 

[Gautam]

That's why there is confusion RPM are used in barracuda subs as a axillary motor in case of main motor failure.

Yep, the French use a similar set up.

What is the use of main motor generator when there is diesel generator unless we want to recharge the batteries even submerged.

Main motor for propulsive power. Diesel gen sets for sensors, comms, weapons etc.

 

[Chain Smoker]

Yep, the French use a similar set up.

Main motor for propulsive power. Diesel gen sets for sensors, comms, weapons etc.

Then what about turbo generator for driving shaft. I think diesel generator in Nuclear Submarine is used in case of failure.

 

[Parthu]

If I'm not wrong the Barracuda actually uses only a 20 MWe electric motor to drive the pumpjet.

@Gautam

is there anything definitive to say that the 35 MWe motor shown in the schematics is for the SSNs and not for S-5 SSBN? It's been a while since I've seen that document.

 

[Gautam]

is there anything definitive to say that the 35 MWe motor shown in the schematics is for the SSNs and not for S-5 SSBN? It's been a while since I've seen that document.

Nope. Just my guess. The timelines for the SSN & the S5 are very close. There is only one motor under development. I presumed both subs will use the same motor.

Do you have any info on any other propulsion motor under development ?

 

[Amarante]

https://twitter.com/x/status/1476204012353458177

 

[Parthu]

https://twitter.com/x/status/1476204012353458177

This means the "Arihant Stretch" class can carry either 8 x long-range SLBMs (K4/K5) or up to 24 x medium-range ones (K15).

Once S-5 class takes over deterrence role (beginning sometime in 2030s), the first four nuclear boats could end up as SSGNs - assuming the silos that can carry 3 x K15s of 0.72m diameter can be made to carry up to 5 or 6 Nirbhay-type LACMs of 0.52m diameter, the two older Arihants could deploy up to 20-24 vertically launched long-range land attack cruise missiles, while the two Stretch variants can deploy 40-48 cruise missiles.

A truly significant conventional land-attack capability.

 

[Ankit Kumar]

Rourkela Plant steel to be used by Indian Navy for making submarines

A high-level navy delegation led by Rear Admiral R Vishwanathan interacted with SR Suryavanshi, executive director (works) and other senior officers of the Odisha-based RSP on January 13 for commercial production of DMR grade speciality steel, it said.

www.google.com

 

[_Anonymous_]

Rourkela Plant steel to be used by Indian Navy for making submarines

A high-level navy delegation led by Rear Admiral R Vishwanathan interacted with SR Suryavanshi, executive director (works) and other senior officers of the Odisha-based RSP on January 13 for commercial production of DMR grade speciality steel, it said.

www.google.com

The steel for our SSBNs & forthcoming SSNs still come from Russia though as per PKS. This must be for the Scorpene & the MLU of the Sindhugosh & Shishumaar classes.

 

[Paro]

The steel for our SSBNs & forthcoming SSNs still come from Russia though as per PKS. This must be for the Scorpene & the MLU of the Sindhugosh & Shishumaar classes.

Sail has already been producing some amount of steel for the scorpions. This is DMR292A. Its for the nuclear fleet.

Navy, DRDO, SAIL in tie-up for producing steel for submarines

The Indian Navy’s Directorate of Naval Design, in collaboration with Defence Research and Development Organisation (DRDO) and Steel Authority of India Ltd (SAIL), has developed a special grade of steel for indigenously designed nuclear-powered stealth submarines.

www.financialexpress.com

Something not in the news. Tata was the consultant as they have experience producing similar grade steel in UK.

 

[_Anonymous_]

Sail has already been producing some amount of steel for the scorpions. This is DMR292A. Its for the nuclear fleet.

Navy, DRDO, SAIL in tie-up for producing steel for submarines

The Indian Navy’s Directorate of Naval Design, in collaboration with Defence Research and Development Organisation (DRDO) and Steel Authority of India Ltd (SAIL), has developed a special grade of steel for indigenously designed nuclear-powered stealth submarines.

www.financialexpress.com

Something not in the news. Tata was the consultant as they have experience producing similar grade steel in UK.

Then in all probability this is for the SSN for as per OSINT all the hulls of the Arihant class were already fabricated by 2015.