Saturday, March 22, 2008

Transition to Eminence - Indian submarines

Chapter 10 - Indigenous Submarine Construction - The SSK Project


- Preamble

- The Considerations That Led to the Selection of HDW

- The Considerations That Led to the Selection of HDW

- The May 1977 Delegation to Evaluate European Submarine Building Yards

- The May 1979 Policy Technical Delegation to Italy, Germany and Sweden

- Indo German 'Agreement on Technical Assistance'

- Contracts Signed on 11 December 1981

- Contracts Signed on 11 December 1981

- Teams Deputed to Germany for Overseeing Construction and Design Technology

- Submarine Construction Schedule

- Commencement of the Type 1500 Design by IKL

- Full Scale Submarine Model

- Transfer of Submarine Design Technology

- Construction of SSKs 1 and 2 in Germany

- MDL's Submarine Construction Facilities

- Construction of SSK 3 and 4 in Mazagon Docks

- Dropping of SSKs 5 and 6 and Discontinuance of Indigenous Submarine Construction


In the 1960s, the conventional wisdom, based primarily on Western naval journals, was that “Russian submarines were noisy and that Western submarines were quieter”. In the deadly game of hunter killer submarine warfare, where one submarine stalks another submarine deep under the sea, the quieter submarine has the advantage of being able to detect earlier, the noisier submarine.

As early as 1960s, the Navy started considering the construction in India of smaller SSK submarines specifically for submarine versus submarine operations.

By 1969, ideas crystallized to build small SSK submarines in India in collaboration with a European firm, on lines similar to what was being done for surface ships in the Leander Frigate Project. Discussions had been initiated with Dr Gabler, the reputed and experienced designer of German submarines during World War II.

What started as a project to build small submarines gradually ballooned into a larger coastal submarine. By the time Dr Gabler's design met the Navy's staff requirements, its cost had overshot the resources available. These discussions however, helped the Navy to understand the complexities of submarine design and the tradeoffs that had to be made in the 'staff requirements'.

Since foreign exchange was always a constraint on acquiring ships, submarines or aircraft from European sources, enquiries were initiated with the Soviet Union. Their response was that they did not have any submarines of the size and characteristics that the Navy wanted, but they could design one.

After the 1971 Indo Pakistan War, the project for indigenous submarine construction resumed momentum. In response to enquiries for constructing SSK submarines in India, proposals were received from the reputed submarine manufacturers of Europe.

Evaluation of these proposals helped to update the staff requirements for a SSK submarine of about 1,500 tonnes.

A delegation visited Sweden in 1973 to discuss the feasibility of collaborating with Kockums for building submarines in India.

The steep rise in oil prices after the 1973 Arab Israel War perpetuated the shortage of foreign exchange and the SSK project had to be deferred. Comparative evaluation continued of the various proposals.

A study was also carried out as to which of the shipbuilding yards Mazagon Docks in Bombay or Garden Reach in Calcutta or Hindustan Shipyard in Vizag should undertake the SSK project. Submarine fabrication required specialised heavy duty machines. For fabricating the hull, the shipyard had to have a Plate Bending Machine to bend the ring frames made of special, 35 mm thick, steel plate. The shipyard had to have Platter and Assembly Shops for profile cutting and edge preparation of these thick steel plates prior to welding. Highly specialised welding skills were required to weld these ring frames together to form a circular pressure hull, which would withstand the crushing pressure of the sea at deep depth.

Mazagon Docks in Bombay had some of these machines in its yard where oilrigs were being fabricated for the Bombay High Offshore oilfield. And Mazagon Docks was near to the engineering subcontractors in the Bombay industrial area to whom the machining and fabrication of non-critical jigs and fixtures could be entrusted. It was decided that Mazagon Docks was best suited for collaboration in the building of SSK submarines. MD started preparing for this project.

Also by 1979, the Navy was able to evaluate in great detail the pros and cons of the German HDW Type 1500 and Kockums Type 45, both of which were still on the drawing board. Kockums shipyard, despite being highly automated (all designing was done by computer, without the help of a scale model) and having excellent infrastructure, had not exported any submarines and their experience was limited to building submarines of 1,400 tons for the Swedish Navy. On the other hand, the HDW shipyard had built 130 submarines for the German Navy, had exported 60 submarines. It was building submarines for numerous countries and was backed by the design organisation IKat Lubeck. IKhad an efficient design facility founded by Dr Gabler and fully backed the HDW shipyard in submarine design.

The Considerations That Led to the Selection of HDW

In 1975, the Apex Defence Review Committee supported the Navy's proposal for constructing submarines. The Soviet Union had already indicated that it did not have submarines of the size that the Navy was looking for. In 1977, Government accepted the requirement for looking at alternate sources for building submarines.

The May 1977 Delegation to Evaluate European Submarine Building Yards

The delegation was led by Rear Admiral NP Datta and comprised three submariners Commanders (X) VS Shekhawat, (L) Thukraand (E) Chaudhury.

Rear Admiral (later Vice Admiral) NP Datta recalls:

“As DCNS, I was part of the delegation which went in 1977 to five European countries France, Germany (two shipyards in Germany), Holland and Sweden to evaluate the various types of submarines offered to us. We shortlisted two possible sources of cooperation. These were the two German shipyards and the Swedish Kockum shipyard.

“We ruled out the French Agosta primarily because it was too small for our requirement, it was not fully tropicalised and they had no great advantage in sensors and weapon systems over the Russian submarines that we had.”

Commander (later Admiral) VS Shekhawat (who had commanded submarines) recalls:

“I accompanied Admiral Datta to Europe in the early part of 1977. We visited shipyards in Germany, Sweden, Holland and France to see what they had to offer which could be compared with the earlier Swedish offer, both in technological terms as well as in financial terms, transfer of technology, support, documentation, etc.

“The visit to France was disappointing. They were reluctant to even show us their Agosta class submarine. After some pressure had been exercised, they agreed to take us to see an Agosta that was building in Cherbourg.

“As far as the Dutch submarine was concerned, it was too small for our requirement though they showed us two submarines of a very interesting design.

“Germany's HDW seemed well positioned to build submarines for us. They had already supplied a number of submarines to other countries. They had the background and experience of the German Submarine Fleets during the First and Second World War a considerable body of experience and data available from what were extensive seagoing operations. And German Industry, both prewar and postwar, had a reputation for engineering skills and thoroughness.

“Having studied the Kockums submarine theoretically and having had a glimpse of the HDW facilities and visited a submarine being built for a South American country, my own views were that eventually it did not very much matter which of these two submarines we went in for because the idea was that we should develop the capacity to design and build for ourselves.”

Captain M Kondath was the Director of the Submarine Arm and dealt with the SSK Project from 1977 until the contract was signed in 1981. He recalls:

“In the Directorate of the Submarine Arm, we analyzed the report of this 1977 delegation. When it was put up the Government, the Ministry suggested that every submarine building shipyard, including Russian, should be invited to offer their proposals. Britain did not respond except for offering their wire guided torpedoes.

“Formal proposals were received from:

- Howal Deutsch Werke (HDW) of Kiel, Germany for their Type 2091.

- Thyssen Nord See Werke (TNSW) of Emden, Germany for their Thyssen 1500/1700.

- Italcantieri of Italy for their 'Sauro' class.

- DTCN of France for their 'Super Agosta' class.

- Kockums of Sweden for their Type 45 B/Naaken.

- Nevesbu of Holland for their 'Swordfish” class.

- Vickers of Britain for the wire guided Tigerfish torpedo.

“A paper evaluation was carried out of these offers. Based on this initial evaluation, the shipyards were requested to indicate if they were prepared to modify their design or alternatively design a submarine to meet the Navy's staff requirements. Holland and France declined and withdrew from the list of contenders.

CCPA Approval in Principle

“Approval in principle' was accorded in February 1979 for the induction of four submarines from non Soviet sources, two to be built abroad and two to be built in India. The total outlay estimated at that time was Rs 350 crore (including Rs 275 crore in foreign exchange). Mazagon Docks, which was to build the submarines, was to invest around Rs 10 crores on infrastructure. Approval was also accorded for setting up a Negotiating Committee.”

The May 1979 Policy Technical Delegation to Italy, Germany and Sweden

The Shipyards were informed of the points that the Indian side wanted included in an inter Government MOU:

- The foreign shipyard has the necessary authorization of its Government to sell submarines to India.

- The shipyard is authorized to collaborate with India for constructing submarines in India under license and with provision for incorporation of subsequent improvements and modifications.

- Assurance of the supplier Government for continued product support in alights aspects for the life cycle of the submarines or for 25 years.

- Similar assurance that no prohibitions or restrictions will be imposed by the supplier Government on the supply and services and continued flow of product support for that period.

- Authorizing the shipyard for transfer of the full range of technology for the construction of submarines in India.

- Transferring from the supplier's Navy the full range of design technology for the development of submarine design capability in India.

- Government clearance for sale to India of connected weapons, armament, sensors, machinery and systems.

- Support by the supplier Navy for the training of:

o Naval and Dockyard personnel for the operation, maintenance, repair and overhaul of submarines and the related systems.

o Naval crew in all aspects of submarine warfare including tactical doctrines and electronic warfare, consistent with national commitments.

o Indian personnel for the logistic support for the submarine and its systems.

- Quality control, certification, trials and acceptance of the submarine and its related systems by the supplier's Navy and supply of necessary documentation.

- Assurance by both sides regarding security of information and equipment.

- Consultations between the two Governments to resolve problems, if any, arising out of the implementation of the collaboration project.

Indo German 'Agreement on Technical Assistance'

As a policy, the German Government avoided defence supplies that might aggravate tension. After the 1971 Indo Pakistan War, the Indian subcontinent had been declared an area of tension. It was also reluctant to supply defence equipment to non NATO countries because such equipment might be used against their allies.

In the end 1970s and early 1980s there was skepticism in Germany, France, Britain and Italy, that if the scope of defence cooperation with India was enhanced, India because of its close relationship with the Soviet Union may not be able to protect NATO hi-tech information from Soviet espionage.

In view of these considerations, India considered it essential, as a measure of abundant caution, that before contracts were signed, there should be agreement at the Government to Government level to safeguard Indian interests. The 1979 Delegation had already informed the European shipyards of the safeguards that the Navy would like incorporated in an Inter Government Memorandum of Understanding (MOU).

Between June 1980 when the CCPA approved the collaboration with HDW for the SSK Project and December 1981 when the contracts were signed, there were detailed discussions to formulate the MOU. The best that could be achieved was an 'Agreement on Technical Assistance' between the German and Indian Ministries of Defence. This was signed in July 1981.

Contracts Signed on 11 December 1981

After detailed negotiations, contracts were signed in on 11 December 1981:

- To build two submarines at the HDW yard in Germany, where Indian personnel would acquire practical training in submarine construction techniques and Indian naval architects and overseers would learn how to design, understudy how to build and oversee the construction of submarines.

- To transfer technology and material packages to MDL for building two more submarines in India. MD personnel would acquire on job training in Germany during the period when the first two submarines were under construction.

- Giving the Indian side the option of ordering material packages for two more submarines before December 1982 at the same baseline cost as the first four submarines.

- Supply of wire guided torpedoes.

Subsequently, in 1985, a contract was signed for the SSK Simulator for installation in the Submarine Headquarters Complex in Bombay.

Teams Deputed to Germany for Overseeing Construction and Design Technology

The teams deputed to the HDW shipyard at Kiel were:

- Overseeing and Quality Control Teams of the two submarines to be built there.

- Key personnel of the commissioning crews.

- Base and Dockyard Teams to undergo training for manning, maintaining and repairing sonar, torpedoes, shafting, main diesel, compressors, auxiliary machinery, hydraulic systems, damage control, power generation distribution and propulsion, ESM, gyro and navigation aids, refrigeration and air conditioning, etc.

- Material Management and Logistics Group and the Documentation Cell.

The Submarine Design Team was deputed to IKat Lubeck and the Naval Armament Inspectors were deputed to Wede to inspect and accept the torpedoes.

Submarine Construction Schedule

- 12 months for planning.

- 6 months for preparation of detailed engineering drawings.

- 6 months for part fabrication and assembly of subunits.

- 12 months for complete fabrication.

- 6 months on the pontoon for fitting out.

- 6 months for sea trials escorted by a HDW vessel.

- Total time 48 months.

Commencement of the Type 1500 Design by IKL

IKL started work on the detailed design only after the conclusion of the contract because the weight and volume calculations could only be carried out during placement of orders.

Full Scale Submarine Model

To aid production by HDW, IK produced a finished model of the Type 1500 submarine. All equipment, machinery, cables and pipe fittings were modeled. Three Indian Navy shipwrights participated in the production of this model.

Transfer of Submarine Design Technology

The programme for the transfer of design technology was formulated through extensive discussion between IKL and NHQ. It was decided that the ideal method for achieving this would be in two distinct phases:

By a combination of formal lectures and discussions with IK experts, IK would give to the Design Team complete details of the design of the Type 1500 submarine.

To check whether the Design Team had fully understood the complexities of submarine design, it would, under the guidance and supervision of IKL's experts, develop de novo a new design according to the staff requirements specified by NHQ.

Design Training started in 1982. By mid 1984, 98% of the syllabus was completed and the Design Team became fully occupied with the de novo design.

Construction of SSKs 1 and 2 in Germany

Captain (later Rear Admiral) DN Thukral, an experienced submariner, was deputed to HDW as the leader of the Indian Naval Submarine Overseeing Team (INSOT) from 1982 to 1987 when the first two submarines were under construction in Germany. He recalls:

“In Germany, Professor Gabler was known as the 'Father of Submarine Design.' Ingeneer Kontor Lubeck (IKL), the design arm and Machinen Bow Gabler, the manufacturing arm, were located in contiguous premises he looked after both of these. While we were there, he turned 75, there was a big function, and he handed over charge of both the design and the manufacturing aspect to two directors who had been with him for a number of years. It was a very professionally run organisation.

“Our submarines were designed by Professor Gabler. He was with us throughout the period when HDW was constructing our submarines. There is no doubt that his experience was unbeatable. He treated the Indian Design Team with great respect because he realised that the IQ level of the technical officers that the Navy had sent was high. He was with them not only at the senior level, but also at the junior level when they were doing the design and doing mock ups. He would saunter into the Design Room and interact with our people. He really was a 'father figure'. I have a lot of respect for him.

“There were two separate contracts one for the submarines to be built in Germany and one for the submarines to be built by MDL. There was a dual responsibility. Firstly, to inspect the submarines being built in Germany and secondly to build the submarines in India.

“The task of building the submarines in India was that of Mazagon Docks. Their team was the first to arrive in Germany. They had been carefully selected to learn all aspects of submarine construction. MDL's team was also responsible for the inspection of the German material packages to be shipped to India for the 3rd and 4th submarines.

“Right from the initial planning stages, it was decided at Naval Headquarters that there had to be a dual presence in the shipyard at Kiel. The first was that of the Naval overseers who were directly from the Navy as the Indian Naval Submarine Overseeing Team. The second presence was of MD who had to learn how to build the submarine, how the material package was to be dispatched to India in a phased and timely manner and to ensure that the inspectors who were from the Navy would eventually transfer their expertise to MDL.

“In the overseeing team I had two categories of people. The first lot were there for approximately a year and a half they were supposed to learn their part of it, then go back to India and start the inspections for the first one and a half years of the MD programme. By this time, the rest of the Kiel team would have learnt the balance part of inspections and would go back to India and take on the specialised inspections of the latter half.

“My team had technical professionals from the Engineering, the Electrical and the Hull side. We laid down our own priorities. Quality was to be Number One priority because there is nothing like a 99% safe submarine; it has to be 101% safe. The second priority was Timely Completion. Most projects had the bad reputation of having time and cost overruns. Quality and Time were the two major aspects that we looked at, at every stage.

“I must highlight that we were concurrently learning and applying the knowledge to inspection. We were learning from the German Organisation called the BWB, which oversees quality assurance for the German Navy, as well as for a foreign Government if the foreign Government decides to use their facility. It was recommended by HDW that BWB were meant for this purpose and, for a small fee, one could use their facilities. So we had a presence of BWB in the shipyard.

“Initially, we learnt from them and finally, having picked up whatever was required, we carried out the inspection ourselves. The important thing was that our team realised that time overruns are caused whenever there is a delay in inspection. If a certain function by the shipyard has been completed and the next step can only be taken after inspection, then it has to be done immediately. There is no question of weekends or waiting for the next morning. If a schedule was made that a certain inspection was to be done at a certain time, we were there to do so, all the time.

“Initially, in the implementation stage, we had very few hiccups in Germany. Those that did occur were absorbed well in time, because when the contract was finalized with the Germans, tremendous penalties had been stipulated for delays.

“But soon we had problems. The first problem was the rejection of a number of sections of the first submarine hull. And linked with this were 'welding technology' problems.

“There were a certain number of ring frames, which had been specially designed for automatic welding. The welding of these sections required a very carefully controlled environment temperature wise and humidity wise to make sure that the weld was totally defect free. Earlier, most of HDW's welding was manual. These automatic welding stations had their teething problems and some of these problems caused permanent damage. Repairing a badly welded frame costs four times more than a new frame. The Germans initially tried to say that 'This is OK, we will get the welding institutes to have a look at it'. But I would like to compliment the support we got from Naval Headquarters who said, 'Just make sure that you do not get pressurized. Go ahead and take the assistance of anybody, whether in India, or Germany or abroad.'

“Luckily, when we approached the welding institutes and the people who were welding technology experts in Germany, they agreed with our stand. The BWB also supported us 100% and said 'Yes, you are right to reject them. There are hair line cracks and we cannot accept any kind of nonsense as far as quality is concerned.' And, therefore, some seven or eight sections had to be rejected.

“It probably cost HDW a few million marks but finally they accepted the fact. Later, after a couple of years, we read reports in various technical journals where HDW tried to tell the world that for the sake of quality they had sacrificed so many million marks. As far as we were concerned, we never allowed any aspect of submarine quality to be jeopardized. Eventually, the HDW yard realised that we were professionals.

“German Navy submarines had not experienced this kind of welding problem because all German submarines were of smaller lengths and their sections were welded manually. This was the first time that specially constructed automatic welding stations were being used by HDW. I can only say that these were teething problems.

“With a view to becoming self reliant in submarine design, Naval Headquarters had deputed a separate design team to IKL to acquire hands-on design experience under the supervision of Dr Gabler. Project X was the code name given to an indigenous design of a submarine. It was supposed to be a little larger submarine than the Type 1500. It had a dual objective. Firstly, to learn how to design a submarine. Secondly, to meet the staff requirements, which were given to the Project X team.

“The Overseeing Team was also involved in the training of the crews and the sea trials. Our crews had two elements of training. One was classroom training. We had selected experienced submariners for these submarines and very few were new, so that aspect was not difficult at all.

“For sea training, we divided the crews into two halves. One on morning shift and one on evening shift, on the same submarine, depending on the time available. Sometimes, when both our submarines were at sea, we had a little more flexibility. Let me take one submarine, one crew. Normally, the Germans did the operation of the submarine during sea trials. Because of the safety aspect and the fact that you cannot cross the figure of 40 because of the limitation of the size of the rescue sphere. These were some of the mandatory aspects that you just cannot avoid. You cannot carry 41 bodies on board. Therefore, it had to be 20 German crew and 20 of our crew Consequently, training had to be slightly lengthened to make sure that every man got his man days or man hours on a particular equipment or in operations or in navigation or whatever. This had been carefully planned and, therefore, the entire submarine training as far as the crew was concerned went more or less on schedule.

“Then there were other elements where the inspection teams were not involved in the full aspect, except for relevant people. For example, the sonar trials and the weapon firing trials etc were done by the HDW team teaching our people. The German Navy provided targets as and when required and the training aspect was generally handled by HDW.

“As regards sea trials, we had difficulties from time to time. Certain equipment that did not function absolutely correctly had to be either replaced or repaired. I would say that by any universal standard, it was a satisfactory period. Hitches are there in any choice and I do not think we got a larger share of problems than normal.

“The specifications of the submarines that we ordered were spelt out in tremendous detail in various volumes. Except for minor changes, which resulted on the basis of trials carried out or some technical reason, no major changes were brought about. Minor changes of adding a weight here or shifting an item from A to B were effected as necessary. Technically, the submarines are absolutely sound.

“Right from day one, the Submarine Overseeing Team found themselves in a very professionally run organisation. We realised that we had a lot to learn and to apply that learning to inspection. Therefore, the interaction with the shipyard personnel had to be very professional. This paid us dividends eventually because the quality of our submarines has been outstanding as has been borne out of the experience of the last 13 years.”

The first two submarines built in Germany were commissioned as INS Shishumar (S 44) on 22 September 1986 and INS Shankush (S 45) on 20 November 1986.

MDL's Submarine Construction Facilities

MDL had started liaising with HDW immediately after the CCPA had decided on HDW in June 1980. In May 1982, a separate liaison office was started at the HDW shipyard at Kiel.

Separate and dedicated submarine construction facilities were set up in MDL's East Yard. They consisted of three large workshops and a dry dock:

- The first workshop, 50 m x 25 m, had two 20tonne cranes for fabricating the ring frames of the pressure hull.

- The second workshop, 100 m x 30 m, had two 60tonne cranes for fabricating pressure hull sections.

These two workshops were completed in February 1984.

The Prime Minister, Mrs Indira Gandhi, formally inaugurated the 'submarine construction facilities' on 6 May 1984.

- The third workshop, 99 m x 35 m, was for fitting out and joining the pressure hull sections to form a complete submarine. This workshop and the 90 m x 17 m dry dock, with alights services, were completed in February 1986.

A separate dedicated Pipe Shop and a Stores Complex were also built in the East Yard.

Construction of SSK 3 and 4 in Mazagon Docks

The shipping, from Germany, of the material packages, along with the first set of drawings, had commenced in 1982 and went on till 1983.

Construction of the third SSK commenced on 12 January 1984. It took five years for her to be launched on 30 September 1989 and three more years till she commissioned as INS Shalki (S 46) on 7 February 1992.

Construction of the fourth SSK began on 12 September 1984. She commissioned ten years later as INS Shankul (S 47) on 28 May 1994.

Dropping of SSKs 5 and 6 and Discontinuance of Indigenous Submarine Construction

The HDW contract contained an option clause, to be exercised by end 1982, for two more SSK submarines at the 1981 baseline price, but to which escalation would be 'addable'. For various reasons, NHQ and MoD were unable to exercise the option by 1982 and sought, and obtained, extensions from HDW to hold the baseline price.

From MDL's point of view, it was essential that the submarine production line was not interrupted. If SSKs 5 and 6 were not ordered in time, it would be forced to divert to other jobs, the manpower that was being trained for submarine construction at such high cost.

In the intervening years, NHQ had interacted with HDW on improving the operational capability of SSKs 5 and 6 and for incorporating changes like the better supercharged diesel engine, better sensors and weapons, substitution of obsolescent equipment etc.

By 1985, three options were considered for SSKs 5 and 6:

- Build both in HDW (Favoured by HDW and those who wanted to upgrade the design with the latest equipment).

- Build both in MD(Favoured by MD'to keep the submarine production line going').

- Build one in HDW and one in MD(To get the best of both options).

In October 1985, approval was accorded for the acquisition of two more HDW submarines. Negotiations were to be based on the “one by HDW and one by MDL” option.

The preliminary discussions in 1985 revealed that the prices quoted by HDW had increased steeply. These were never built / acquired.

MDL delivered SSK 3 in 1992 and SSK 4 in 1994. Their operational performance met the Navy's expectations.

Chapter 13 - The Submarine Arm


- Preamble

- Submarine Warfare

- Submarine and Anti Submarine Tactics

- Submarine and Anti Submarine Tactics

- Stealth and Snorting

- Submarine and Anti Submarine Tactics

- Sonar Propagation

- Submarine Location, Detection and Attack

- MRASW Aircraft

- Anti Submarine Ships and Their ASW Helicopters

- Submarine Search and Kill (SSK) Submarines

- The State of the Submarine Arm in 1975

- The State of the Submarine Arm in 1975

- The First Eight Submarines

- Submarine Depot Ship - Amba

- Shortage of Submarine Personnel

- Submarine Infrastructure Facilities

- Developments Between 1976 and 1990

- Developments Between 1976 and 1990

- Six-Yearly Refits (Medium Repairs) of Kalvari and Vela Class Submarines

- The Indigenization of Submarine Propulsion Batteries

- Indigenous Submarine Construction - The SSK Project

- The Induction of Russian 877 EKM (Kilo Class) Submarines

- Personnel Shortages

- Very Low Frequency Communications with Submarines at Sea

- Command and Control of Submarine Squadrons

- Flag Officer Submarines (FOSM)

- FOSM's Interface with the Navy's Command and Control Organisation

- Submarine Rescue

- Nuclear Propulsion for Submarines

- The Lease of Nuclear Submarine Chakra

- The Utilization of Chakra

- Developments After 1990

- Kalvari / Vela Class Submarines

- Chakra

- Submarine Propulsion Batteries

- German HDW 1500 Shishumar Class (SSK) Submarines

- Overview of the Submarine Arm 1976-1990

- Retrospect


This chapter starts with a retrospect of the international law aspects of submarine warfare.

It is followed by an overview of submarine and anti submarine tactics to help the reader to better understand the concerns that drove several inter-related naval developments during the period 1976 to 1990:

- The taking over of the Maritime Reconnaissance role from the Air Force, the induction of Russian I38 MRASW and TU 142 LRMP ASW aircraft and the induction of British Seaking Mk 42 B and Russian Kamov ASW helicopters. These have been dealt with in the chapter on the Air Arm.

- The selection of the German HDW 1500 design for commencing indigenous construction of SSK submarines in India. This has been dealt with in the chapter on “Indigenous Submarine Construction - The SSK Project”.

- The acquisition from the Soviet Union of the latest 877 EKM (Kilo class) SSK submarines to replace the earlier Russian submarines.

- The indigenous manufacture of submarine propulsion batteries for all classes of submarines in service with their designs improved for better performance in tropical conditions.

- The leasing of a Russian nuclear propelled submarine to better understand its capabilities and limitations.

Submarine Warfare

The London Protocol of 1936 stated that submarines must conform to the rules of international law to which surface vessels are subject; and these rules included the provisions that a merchant ship's crew must, before the ship itself was destroyed, be put in a place of safety. Moreover a ship's boat is not a 'place of safety'.

An attempt to fulfill this condition was made in the case of SS Laconia in 1942 when three U boats towed boats full of survivors for several days until attacked by Allied aircraft. Admiral Donitz thereafter sent his famous “Be Harsh” signal to all U boats.

At Nürnberg, the Tribunal gave a hedged judgment:

- It recognized that both sides had conducted submarine warfare of considerable ferocity, and that there had been justification for German attacks on British shipping, particularly as that shipping was defensively armed and had orders to report submarines.

- But it found against Admiral Donitz for conducting attacks on neutral vessels without warning and for the fact that submarine crews had failed to rescue survivors.

During war, international law places submarines under stringent constraints. On the other hand, “It is universally recognized that in every war, the actions of any nation are influenced substantially by the behavior of its opponent.”

The following excerpts from the memoirs of Grand Admiral Raeder, the Chief of the German Navy during the 1939-1945 World War, are pertinent.

“The German Naval War Staff ensured that:

- Every precaution was taken against any violation of the rules of international law in regard to war at sea.

- No actions should be taken, no orders or directives issued, which could lead to a violation of the moral law of the sea as it is recognized by all civilized peoples.

“I knew positively that Admiral Donitz, as Commander of the Submarine forces, had on several occasions deliberately put some of our U-boats and their crews in positions of utmost danger from enemy attack in order to insure the safety of surviving crew members of torpedoed ships.”

At the 1945-46 “trials of war criminals” held in Nürnberg by the Allied International Military Tribunal, Admirals Raeder and Donitz were charged with having 'conducted naval warfare contrary to the rules of civilised warfare' with particular reference to unrestricted submarine warfare by the German Navy. To prepare the defence against this charge, their defence counsel sent questionnaires to the British and American Navies.

“From the answers of the British Admiralty, it was established, and accepted by the court, that at the very beginning of the war, the British Navy had begun arming British merchant ships in accordance with directives already laid down in 1938 in their Handbook for the Merchant Marine. It had also sent ships out under armed escort. British merchant ships had orders to report all submarines sighted, and for this purpose were made part of the British Navy's reconnaissance and warning system. On 1 October 1939, the British Navy had directed British merchant ships to ram German submarines whenever possible. And on 8 May 1940, the British naval forces had received orders to sink, without warning, any ship encountered in the Skagerrak.”

“Admiral Nimitz was equally frank and helpful in his answer to the questionnaire. Immediately upon outbreak of the war with Japan, he avouched, the US Government had declared the whole Pacific Ocean a war zone, and had ordered all-out war against Japan. In this war zone, the largest ocean area in the world, US submarines had authority to attack, without warning, all merchant ships sighted. Hospital ships, and other vessels proceeding under security protection for humanitarian purposes, were the only ships exempted from this directive.

“The crucial question in the questionnaire sent to Admiral Nimitz was this: 'Were American submarines forbidden, either by specific order or recognized practice, to take measures for rescue of the passengers and crews of ships sunk without warning if the safety of the submarines themselves were endangered by these measures?'

The unequivocal reply of the US Admiral was: “In general practice, the US submarines did not rescue enemy survivors if such an attempt meant an unusual additional risk or if the submarine was thereby endangered in the further execution of its tasks.”

“These replies proved to the Nürnberg court that the German Navy had conducted its own naval warfare in accordance with the same rules and customs that were observed by the two largest sea powers with whom it was engaged. As a result, the International Military Tribunal completely vindicated the German Navy in its methods of warfare, certifying that such warfare had been conducted in full accord with the rules of international law.”

Submarine and Anti Submarine Tactics

Stealth and Snorting

Stealth is the watchword of all submarines. The modern, diesel-electric propelled SSK submarine is very stealthy, provided the utmost care has been taken to minimize its self noise. Carefully handled, she can be as quiet as the grave. At low speeds, the soft hum of her electric propulsion power unit is almost un-discernable. Unlike a nuclear propelled submarine, she has no reactor requiring the support of numerous mechanical subsystems, aloof which are potential noise-makers.

When dived, the submarine is propelled by a set of huge electric batteries. Depending on how much battery power is used up (the higher the speed, the quicker the battery runs down), the batteries require to be recharged regularly by diesel generators. Just as a car engine needs an intake of oxygen, so do the two internal combustion diesel generators in a submarine. The diesel engine must have air. To get air, a submarine must come up to at least periscope depth and then she becomes vulnerable to detection.

Batteries can be recharged either by being on the surface (more vulnerable) or by remaining at periscope depth and sucking in air (less vulnerable). When a diesel-electric submarine comes to periscope depth and raises her snort mast to suck in the air required to run her diesel generators to recharge her batteries, the process is known as 'snorting'.

Even though a submarine hull is not visible whilst snorting, the acoustic noise of its diesel engines can be heard by another submarine if in the vicinity. Its periscope and snort masts that stick out above the water can be detected on ship and aircraft radar. The ions in the diesel exhaust can be 'sniffed' by detectors fitted in MRASW aircraft. There is little a submarine can do about these limitations, except to stop recharging and crash dive every time her ESM detects radar emissions of an approaching ASW aircraft/helicopter or her passive sonar detects the noise of approaching ships.

During war, a submarine patrolling in hostile waters comes up near the surface only when she has to recharge her batteries. Even then, she will only do so at night, and for the shortest possible time, so as to minimize the chance of being detected and 'localized' for attack.

Submarine and Anti Submarine Tactics

For successful attack, a submarine relies on concealment and surprise rather than concentration of force. A submarine attack is more successful because it detects the ship earlier and can deliver a high weapon density attack before being detected - this quality provides surprise.

To avoid mutual interference, submarines operate singly. When more than one submarine is deployed in the same region, each submarine is given a specific demarcated area in which to operate.

A submarine stalks its prey. Its target - a warship, a merchant ship, or a convoy - seeks clues as to a submarine's presence in order to take evasive action. In anti submarine warfare, MRASW aircraft, ASW helicopters, sonar fitted warships and SSK submarines are the predators and submarines the prey.

When a submarine closes its target ship or submarine, the latter try to counterattack and evade the blow. When anti submarine forces localise a submarine, it either fights like a cornered beast or goes silent and tries to slip away.

The crux of all submarine warfare is to sink the enemy target, get away from the area and survive the anti submarine chase that is sure to follow.

Sonar Propagation

Sound is virtually the only form of energy that propagates usefully underwater, where electromagnetic waves, including light, are rapidly attenuated.

The temperature of the sea becomes cooler as depth increases. This change in temperature affects the velocity (and hence the path) of the sound waves transmitted by a sonar. Temperature layers in the sea refract sound waves much the same way that a prism refracts light.

The sound velocity gradient near the sea surface is considered 'positive' if velocity increases with depth, 'negative' if velocity decreases with depth.

A positive gradient causes upward refraction of sound energy. Upward refracted rays will be reflected by the air-sea interface at the surface and surface reflection will be continued. Positive velocity gradients give rise to surface bounded ducts that can carry acoustic energy for very long distances since the spreading is two-dimensional. Long-range detection can be made under these conditions if the sonar and its target are both located in this duct.

A negative velocity gradient refracts sound waves downwards. As a result, a shadow zone is created which is not insonifield. Under these conditions, by operating in this shadow zone, a submarine can, without being detected, move close to its target to within torpedo firing range.

The way to detect a submarine lurking in a shadow zone or below a temperature layer is to position the sonar in the same shadow zone or below the same temperature layer. This is achieved on board ships by lowering a large towed sonar dome (called Variable Depth Sonar - VDS) to the required depth whilst maintaining speed. Anti submarine helicopters lower their small sonar dome (called 'dunking sonar') whilst hovering.

Submarine Location, Detection and Attack

Submarines are potent weapon platforms. Their traditional task is to attack enemy warships and enemy submarines. They are designed to minimize the chances of their being detected and to withstand anti submarine attacks. They are equipped with accurate and lethal weapons for attack and for self-defence.

A submarine's asset is its invisibility when dived. Its limitation is that its underwater mobility is constrained by the endurance of its propulsion batteries. When recharging batteries, a submarine loses its asset of invisibility.

As mentioned, when dived, a submarine is propelled by electric motors that are powered by batteries. The endurance of these batteries depends on the speed of the submarine. The faster it goes, either to get as far away from the position where it was first detected or to evade the weapons fired at it, the quicker the batteries get exhausted. The submarine then has to surface and recharge its batteries before it can dive again with its mobility restored by recharged batteries.

The crux of anti submarine warfare is to compel the submarine to remain dived by repeated and intense attacks and thereby exhaust its batteries, to reduce its mobility to evade attack and hit it with weapons to force it to surface and surrender.

In ASW tactics, the ship tries to evade or avoid a submarine probability area. It endeavors to confuse and constrain submarine tactical choices by deft combinations of speed and maneuvers.

MRASW Aircraft

When a submarine is sighted on surface or it makes a wireless transmission that betrays its presence by giving Direction Finding (D/F) equipment an approximate position of the transmission, a maritime reconnaissance anti submarine warfare (MRASW) aircraft speeds to that position. It drops a number of sonobuoys to 'localize' the contact and if possible to attack it. The MRASW aircraft, therefore, is in the first line of submarine location, detection and attack.

The objective of an MRASW aircraft is to obtain an initial position of a submarine. For example an indication on its detector of the 'magnetic anomaly' created by the submarine's steel hull or a 'sniff' of diesel exhaust ions or a disappearing radar contact suggestive of a submarine having crash dived to evade detection. As soon as the MRASW aircraft obtains an initial position, it drops a pattern of passive sonobuoys to localize the contact.

Modern conventional submarines (and their batteries) are designed to minimize the need to snort to a few hours every few days. This time is too short for an MRASW aircraft to get an accurate enough localization. On the one hand, an MRASW aircraft may choose not to use its radar to detect the submarine's snort mast sticking out of the water - but to do so would reveal its presence to the submarine. On the other hand, continuous patrols by MRASW aircraft operating their radar can constrain a submarine's freedom to recharge its batteries.

In rough weather and poor sonar conditions, localization by an MRASW aircraft could be as poor as an area of several hundred square miles, almost like looking for a needle in a haystack.

However as soon as a submarine has been localized and accurately tracked, the aircraft attacks it with its own weapons. Additional MRASW aircraft can help to maintain pressure on the submarine to remain dived.

Anti Submarine Ships and Their ASW Helicopters

As soon as the MRASW aircraft localizes a contact, ships designed for anti submarine warfare and having anti submarine helicopters on board proceed to the area where the MRASW aircraft's sonobuoy patterns have been laid.

Anti submarine helicopters can search a given area quicker and, being airborne, they cannot be hit by submarine fired torpedoes. After ascertaining the progress on localization from the MRASW aircraft, they either lay their own sonobuoys to localize the contact or use their dunking sonar to search. If the sonar search is passive, their sonars listen for tell tale noise of submarine presence.

If the sonar search is active and a submarine is present, the sonar receives an acoustic echo back from the submarine hull and the submarine can be tracked by sonar transmissions. As soon as the submarine's position and movements are accurately determined, helicopters release their anti submarine homing torpedoes. Helicopter attacks continue until the submarine is hit and sinks or the submarine surfaces and surrenders because its batteries have exhausted.

A submarine knows when it has been detected on sonar - it can hear the sonar transmissions. It knows it will come under attack. It will try to evade helicopters. When cornered, it may choose to attack the ship because a ship can be instantly sunk by submarine fired torpedoes.

The role of the anti submarine ship is to stand-off outside the range of the submarine's torpedoes and keep on re-fuelling and re-arming the helicopters until the submarine nears exhaustion. She then moves in to fire intensive barrages of anti submarine rockets.

Submarine Search and Kill (SSK) Submarines

The advantage of having submarines to search and kill enemy submarines is that both share the same undersea environment to detect and track each other, without being limited by shadow zones and temperature layers. Using active sonar would immediately betray presence. Detection by passive sonar requires high skills in picking up even the faintest noise emanating from the opposing SSK. Hence the emphasis, during SSK designs, on silent machinery and minimum noise levels.

SSKs are deployed in areas where there is likelihood of encountering only enemy submarines and no possibility whatsoever of own anti submarine forces mistaking own SSK for an enemy SSK. The contest is between two dived SSKs.

Once the opposing SSK has been detected and tracked and the fire control problem solved, wire guided torpedoes are fired in a way that the target SSK would not have time to fire its own wire guided torpedoes in self defence. In effect, this means getting as close as possible to the victim before firing - but in so doing, it also means that the victim SSK may hear you and fire its own torpedoes before you fired yours. The direction from which the retaliatory torpedoes would come is predictable - straight down the direction that the incoming torpedo's homing head starts its active sonar transmissions. At this moment, decoys can be released to seduce the incoming torpedo away.

Both submarine warfare and anti submarine warfare are driven by constantly evolving frontier technologies. With long years of peace interspersed by short sharp wars, success requires:

- The continuous intensive training of highly motivated and experienced personnel.

- Sustaining the highest standards of material readiness of the platforms (ships, submarines, aircraft and helicopters) and their sensors (sonars, radars and ESM) and their weapons (torpedoes, rockets, and depth bombs).

The State of the Submarine Arm in 1975

The First Eight Submarines

The Submarine Arm started with the acquisition from the Soviet Union of four of their latest Project i 641 K (NATO classification Foxtrot class) 2,000 tonne ocean going submarines. These arrived between 1968 and 1970. The problems experienced in operating the first of these Kalvari class submarines in tropical conditions were fed back to the design bureaus in Russia. Improvements were gradually introduced in the remaining three submarines before delivery.

Another four submarines were contracted for in 1971. These improved Vela class submarines arrived between 1973 and 1975.

By 1975, the material state of the first four submarines had deteriorated. This was a cumulative result of several factors:

- The tropical, hot and humid Indian climate, the corrosion caused by the higher salinity of tropical seas and the corrosive atmospheric pollution caused by the industrial emissions at Vishakhapatnam.

- Bunching. The induction of the first four submarines in 24 months and the next four submarines in 16 months meant that their major six-yearly refits would also have to be undertaken after six years within periods of 24 and 16 months respectively. This bunching of major refits could not have been avoided - it made no sense to order one submarine at a time when starting a Submarine Arm.

- Submarine repairs required highly skilled, experienced and deeply specialised expertise. The Navy did not have this expertise. It could only be built up slowly because officers and artificers were periodically transferred and the civilian cadres of the new Dockyard were being built up from scratch.

Six-yearly refits could not commence on time because the submarine refit workshops and facilities were still coming up in the new Dockyard. The new civilian workforce had no knowledge of submarine repair technology. Even though vertically specialised and experienced Soviet specialists in submarine repair were available, they had no Indian counterparts to whom they could transfer their technology and expertise.

All these factors were aggravated by the procedural delays in the delivery of submarine refit spares from Russia. The only solution was for submarines to be refitted in Russia.

Initially, the Indian side found it difficult to countenance sending submarines to Russia for refit. Not only might it indicate lack of self-confidence, but also because heavy investments had been made in setting up the new Dockyard for this very purpose.

The Russian side too, perhaps for security reasons and their own submarine refit workload, was reluctant to accept Indian submarines in their dockyards. After considerable interaction, both sides realised that there was no other option.

Submarine Depot Ship - Amba

The Submarine Depot Ship Amba had commissioned in 1968 and had been based in Vishakhapatnam. Between 1969 and 1971, Amba supported the submarines operating on the West Coast.

After it was decided to base the four new submarines of the Vela class at Bombay, Amba was re-based at Bombay. She provided the essential battery recharging facilities until a full-fledged battery charging facility was established ashore in 1978. In addition, she had a recompression chamber, could prepare torpedoes, recharge High Pressure air and provide comfortable accommodation for submarine crews.

Shortage of Submarine Personnel

In the short period of eight years between 1966 and 1974, the Navy had manned eight submarines as well as their technical facilities ashore. Personnel shortages began to cause concern. The 'rejection' procedure was reviewed and made more pragmatic. To induce personnel to volunteer, monetary incentives like Submarine Allowance, Submarine Pay, and Hard-lying Money at full rates were sanctioned, special benefits like Special Submarine Rations and Special Submarine Clothing were authorized, procedures were simplified and sustained recruitment drives were resorted to.

Submarine Infrastructure Facilities

The 1965 agreement with Russia covered not only the delivery of ships and submarines, but also the creation of a modern dockyard at Vishakhapatnam, along with infrastructure.

The shore infrastructure for the Submarine Arm comprised a submarine base, a submarine training establishment, submarine maintenance and repair workshops, facilities to charge submarine propulsion batteries and high-pressure air bottles and facilities for blowing the ballast tanks and preparing submarine torpedoes. Since the new Dockyard would take several years to come up, interim arrangements were made for the Base Repair Workshop in Vishakhapatnam to be expanded.

Developments between 1976 and 1990

Six-Yearly Refits (Medium Repairs) of Kalvari and Vela Class Submarines

It was decided that the first submarine, Kalvari would be refitted by the Russian side in Vladivostok and that the second submarine, Khanderi would be refitted in Vishakhapatnam. A team from the Naval Dockyard Vishakhapatnam was deputed to participate in Kalvari's 18-month refit in Russia to acquire hands-on experience of a six-yearly refit and, on return to Vishakhapatnam, to assist in carrying out Khanderi's refit with the help of Russian specialists.

Kalvari started her refit on 1 January 1975 and returned to Vishakhapatnam in mid 1976 with 'zero defects'. The performance of her equipment was so satisfactory that Kalvari provided the benchmark for the high standard that Vishakhapatnam had to achieve for Khanderi's refit.

When Khanderi's refit started in mid 1976, the position was:

- The new Naval Dockyard under construction at Vishakhapatnam was nowhere near ready to undertake such a complex refit. The only facilities available were a two-and-a-half-bay, rudimentary, Base Repair Workshop, the submarine battery commissioning / charging-discharging facility called the Energy Block, and the Torpedo Preparation Workshop.

- There was neither the capability for the survey of a submarine's pressure hull nor a naval dry dock in which to dock a submarine.

- The team of Dockyard officers and civilian foremen that had been deputed to Russia to participate in Kalvari's refit had, to a limited extent, imbibed what needed to be done, how it was to be done and how best to improvise facilities in Vishakhapatnam until the new workshops were ready.

- The set of Refit Spares required for the mandatory, time-bound replacement / overhaul of critical equipment had not arrived.

- The Repair Technical Documents (RTDs) required for the repair and refit of equipment were incomplete. Whatever had been received was in the Russian language. There was a shortage of translators and a backlog had built up of documents awaiting translation from Russian into English.

On the plus side, the expert civilian Russian specialists from the factories that manufactured equipment could be requested for to assist and provide guidance on how to refit the equipment.

However, Russian specialization was very narrow - each specialist from each manufacturing factory knew all about his specific equipment but not much about the other equipment.

The Indian side was reluctant to afford the high costs that would have to be incurred for the deputation of such a large number of specialists.

The Khanderi refit was beset with all these problems. There was no way to overcome the inexperience of dockyard workers, their low productivity, their learning curve, their low expertise, the shortage of spares and documentation and the inadequate infrastructure.

In 1980, the Naval Expert Committee was constrained to comment:

“Over 80 Soviet specialists had been imported for facilitating Khanderi's medium refit. Each one of them was a specialist in repair of submarines. The Chief Shipbuilder had an experience of about 12 years in refitting submarines alone. Soviet specialists included ship builders, designers, technologists, specialists in quality control, electro-deposition and specialists on almost each important equipment and system on which they had long experience.

“Despite the Soviet specialists, the refit was taking more than twice as long and was nowhere near finishing. If the Navy had to acquire and replicate the expertise possessed by the Soviet specialists, in time to come, the following steps were unavoidable:

- Undertake most meticulous planning of work and material requirements.

- Create Bureaus of ship builders, technologists and designers as recommended by the Soviet side, consisting of 32 Technologists and 15 Designers for submarines alone.

- Create a core of supervisory staff and workers and specialise only in refit of submarine hull and its equipment. This would mean a larger requirement of manpower, but narrow specialization to preserve the quality of work appeared to be the only answer to the problems being experienced.”

Kalvari's refit in Vladivostok had lasted 18 months. Khanderi's refit in Vizag lasted five and a half years, from 1976 to 1981. It was, nevertheless, a significant learning experience. Considerable innovation had to be resorted to as was done for testing critical equipment like high-current-carrying propulsion battery breakers and the back-to-back testing of the overhauled main electric-propulsion motor.

In subsequent years, both expertise and productivity gradually improved. For the reasons discussed in the chapter on Logistics, the delivery of Refit Spares continued to remain untimely. Delays were inescapable in the completion of a massive project like the new Vishakhapatnam Dockyard. And because the submarines were acquired in bunches of four, there was no escape from the 'bunching' of their six-yearly refits.

Kursura was laid off for a number of years and cannibalized to keep the other submarines operational. In 1985, it was decided to make her operational. Subsequently, she sailed and dived for a full operating cycle before she was pulled up on to Vishakhapatnam beach after decommissioning in 2001 and made into a museum. In 1987, Khanderi was laid up for cannibalization, as Kursura had been earlier.

The overall sharing of the six-yearly refits (Medium Repairs) of the first eight submarines between refit yards in Russia and Vishakhapatnam was:

- Russia:Kalvari (1975-76), Karanj (1978-79), Vela (1980-82), Vagli (1981-84), Vaghsheer (1983-85)

- India:Khanderi (1976-81), Kursura (1977-95), Vagir (1981-84), Kalvari (1984-88), Vela (1986-88), Karanj (1988-96),Vela (1993-98),Vagli (1997-99)

The Indigenization of Submarine Propulsion Batteries

From the inception of the submarine acquisition programme, the Navy had decided to become self sufficient for its requirements of submarine propulsion batteries. The offers of competing Indian firms and their foreign collaborators were evaluated. Standard Batteries of Bombay were chosen in 1973 to manufacture propulsion batteries in technological collaboration with Tudor of Sweden.

The first eight submarines had commissioned with Russian propulsion batteries. Each submarine's set of batteries weighed over 300 tonnes and comprised 448 battery cells, each one meter high, and half a meter wide. The set had to be charged before loading on board. To recharge the batteries at sea, a submarine had either to come to the surface or, to be safer, come to snort depth, and use the diesel generator for recharging. The battery set had a life of 100 charge-discharge cycles or two and a half years, whichever was earlier. The Russian Navy had adjusted their submarine operating cycle such that these 100 cycles would be expended between three-yearly refits called Current Repairs. To avoid having to lay off an operational submarine during its operational cycle, the Russians always installed a set of new batteries during the three-yearly refit.

The Navy's experience with Russian batteries soon revealed that in Indian tropical conditions, the evolution of hydrogen when recharging the batteries was much greater than in the cooler Russian weather. Mixing additives to the electrolyte solved this problem partially. A basic design problem, however, was the inability of the electrolyte cooling system in the Russian battery to cope with high tropical temperatures.

Standard Batteries modified the design of the Swedish Tudor battery to overcome these problems. It innovated tubular construction instead of grid construction and, instead of having cooling coils in the electrolyte, it achieved more efficient cooling through ducts in the bus bars. After the initial teething troubles had been overcome, the performance of indigenous batteries proved to be better in Indian conditions than that of imported batteries.

The German HDW submarines, which entered service in 1986, were equipped with German Hagen batteries. The design of the Hagen battery was indigenized by Chloride India, the makers of Exide batteries.

The Russian EKM submarines started entering service from 1986 onwards. The indigenization of their batteries was once again entrusted to Standard Batteries.

In 1990, the Battery Commissioning Facility in Bombay was completed. It met the requirements of the both the EKM and HDW submarines based at Bombay and dispensed with the need for Russian submarines to go all the way round to Vizag to replace their batteries.

The indigenization of submarine propulsion batteries was a success story. Despite setbacks and teething problems, perseverance, innovation and close interaction between submariners and the factories culminated in the production of propulsion batteries that had superior cooling power in the tropics, longer life, higher capacity, superior plate technology all of which helped to lower indiscretion rate. In later years, Russia and other countries started importing these batteries from India.

Indigenous Submarine Construction - The SSK Project

In the early 1970s, proposals were invited from reputed and well-established submarine manufacturers. Based on the technologies reflected in the offers that they sent, the Navy incorporated the desired features of each proposal and informed them of its 'revised staff requirements'.

In 1981, after prolonged evaluations, a contract was signed with HDW of Germany for four 1,500-tonne submarines - the first two to be built in Germany and the next two by Mazagon Docks, Bombay. The German-built submarines commissioned in 1986. Due to initial start-up problems, the submarines built by MD commissioned in 1992 and 1994.

The selection and construction of these submarines have been discussed in the chapter on “Indigenous Submarine Construction - The SSK Project”.

The Induction of Russian 877 EKM (Kilo Class) Submarines

In the late 1970s, the Russian side was requested to suggest replacements for the eight Foxtrot class submarines that had been inducted in earlier years, concurrently as the case was on for building SSK submarines in India. The Russian response in 1978 was that the EKM design was on the drawing board and that India should make up its mind quickly so that its requirements could be bulked. The Navy was hesitant to do so, seeing in the Russian offer, perhaps rightly, that it was to compete with the Swedish and German SSK evaluations then in progress. Years passed. In February 1981, the Russian side offered the 877 EKM submarines. The Navy asked for its team to see the 877 but was asked to wait. By this time, the decision had already been taken to collaborate with HDW of Germany for the indigenous construction of submarines and final negotiations were in progress. The German HDW SSK agreement was signed in December 1981.

In 1983, an Indian team visited and evaluated the 877 and found that its design and performance as an SSK was comparable to that of the HDW SSK. In 1984, an agreement was signed for six submarines. The seventh submarine was contracted in 1987 and the eighth submarine in 1988.

These eight 877 EKM Sindhughosh class submarines (NATO classification Kilo class) were commissioned between 1986 and 1990. They were a generation ahead of the earlier i641 Foxtrot class and on par with the German HDW 1500 submarines.

The Moscow newspaper Pravda published the following report in 1988:

“The Sinduratna is an 877 EKM submarine of the Kilo class. When surfaced, she displaces 2,300 tonnes and is capable of a speed of 10 knots. Fully autonomous for 45 days, it can dive to 300 metres, carries a crew of 52 and is equipped with six 533 mm torpedo tubes. The submarine was developed at the Rubin Design Bureau in St Petersburg.

“The 240 feet long, 3,000 tonnes dived, extremely quiet, diesel-electric Kilo class SSK can run submerged at speeds up to 17 knots.

“The battery gives the Kilo a range of some 400 miles, running slowly and silently, before she needs to recharge. She can trave6,000 miles 'snorting' before refueling.”

Almost all the officers who underwent EKM training in Russia gathered the impression from their Russian instructors that the EKM's teardrop hull, its anechoic rubber tiling and other attributes were features of a submarine that was supposed to take a miniaturized nuclear reactor. But during development, either the reactor could not be fitted in the space available or technical problems constrained further miniaturization and it was converted into a diesel-electric propelled boat. This helps to explain why, despite the Russian Design Bureau's experience of the Indian side's need for more air conditioning capacity when operating Russian submarines in tropical conditions, the shortfall in air conditioning could not be remedied before the submarines commissioned.

Commander (later Captain) KR Ajrekar underwent training in Russia and on return to India became Commanding Officer of the Sindhughosh. He recalls:

“Russian training was the best training we ever received. The best part was the training on the torpedo fire control system. The instructor was a commanding officer who had just come from an operational submarine. He had 15 years experience in operational submarines and it was absolutely invaluable. After each attack, we had to point out our own mistakes and the rest of the junior officers watched the commanding officer analyse his mistakes. I found that people did come out with their own mistakes and such mistakes were not repeated a second time.”

Recalling the qualities of the EKM submarine that he commanded, he said:

“The tear-drop hull configuration, being hydro-dynamically the best underwater, the underwater management of the EKM is excellent. The EKM has auto diving control you can steer the submarine automatically even from the fire control computer. The hydroplanes are located in the midship portion where there is no interference with the sonar. The submarine hull is covered with rubber tiles that absorb the acoustic energy of enemy sonar transmissions. The radiated noise of the submarine was very low. The sonar could pick up HE at very long ranges. Never before had I picked up those kinds of ranges. In fact, we thought that we would pick up these ranges only in Arctic waters or the Baltic Sea. However, within a month of our arrival in India, extensive sonar trials were carried out and the ranges obtained were just slightly less than what we had obtained in the Baltic. The sonar is excellent, the underwater telephone facility is excellent, and the intercept sonar is very good. In addition there is mine hunting sonar which is very useful.”

In the initial years, the EKM submarines suffered inadequacy of air conditioning in tropical conditions. This was progressively resolved by increasing the air conditioning capacity. The acute shortage of fresh water was eventually resolved by fitting reverse osmosis plants.

Personnel Shortages

The tempo at which submarines were inducted necessitated measures to increase induction of personnel into the submarine cadre. Basic submarine courses were increased from one per year to two per year and recruitment drives were intensified. But it was only after the Fifth Pay Commission in the 1990s that emoluments improved sufficiently to start attracting personnel of the desired caliber to volunteer for the Submarine Arm.

Very Low Frequency Communications with Submarines at Sea

Whereas a submarine on the surface can transmit and receive wireless messages just like a ship can, submerged submarines can only receive wireless messages on Very Low Frequency (VLF). VLF transmitters require huge antennae suspended high above the ground.

The initial discussions were solely with the Russian side, from whom the submarines had been acquired. Later enquiries with western manufacturers indicated that better technology might be available from America. Parallel discussions were, therefore, pursued both with Russia and with America.

Between 1979 and 1984, modalities were worked out for Continental Manufacturing Company of America, in collaboration with Triveni Sangam Ltd of India, to be responsible for the detailed design, manufacture, site installation and commissioning of the VLF Transmitter and the Auto Transmitting Units.

The hardware arrived by 1986. Installation of the VLF Transmitter commenced in 1987. Trials were completed in 1989.

During the same period, the Defence Research and Development Organisation undertook the design of the antennae to be fitted in submarines for receiving VLF transmissions.

On 20 October 1990, the VLF Transmitting Station was commissioned as INS Kattaboman in Tamil Nadu on the southern tip of India.

Command and Control of Submarine Squadrons

After the arrival from Russia of the fourth submarine in end 1969, all four submarines of the Kalvari class (Russian Project i 641, NATO designation Foxtrot class) constituted the 8th Submarine Squadron. It was based at Vishakhapatnam under INS Virbahu, which commissioned in 1971. CO Virbahu functioned as Captain SM 8 and Class Authority for all submarines.

The next four Vela class improved versions of the Kalvari class were based in Bombay. When the fourth submarine arrived in end 1974, these four submarines, under Captain SM 9, constituted the 9th Submarine Squadron. Captain SM 8 at Vishakhapatnam continued to function as the class authority for submarines.

The first submarine of the Sindhughosh class (Russian Project 877 EKM, NATO designation Kilo class) arrived in 1984. The first four submarines constituted the 11th Submarine Squadron and were based at Vishakhapatnam to facilitate the training of EKM commissioning and replacement crews. Facilities to carry out their annual repairs were taken in hand for completion by 1990.

The first two Shishumar class SSK submarines arrived in Bombay from Germany in 1987 and constituted the 10th Submarine Squadron.

The next four EKM submarines that arrived by 1990 were based in Bombay and constituted the 12th Submarine Squadron. The four ageing Vela class submarines of the 9th Submarine Squadron gradually relocated to Vishakhapatnam.

The last two, MDL-built SSK submarines joined the 10th Submarine Squadron in 1992 and 1994.

Until INS Vajrabahu was commissioned in Bombay in 1996, the submarines based in Bombay were administered locally and Submarine Headquarters in Vishakhapatnam dealt with technical matters.

With multiple squadrons based in Bombay and Vishakhapatnam, the Commanding Officers of Virbahu and Vajrabahu were initially designated as COMSUB East and West and later re-designated as Commodore Commanding Submarines (COMCOS) East and West respectively.

Submarines were placed under the operational and administrative control of the respective Cs-in-C, who were designated as Submarine Operating Authorities. The COMSUBs were responsible to their Cs-in-C for operational readiness and providing their submarines with 'Base' and 'Material' support.

Flag Officer Submarines (FOSM)

The constitution of FOSM was promulgated in 1986 after the arrival of the first EKM submarine from Russia and implemented in 1987 just prior to the arrival of the SSK submarines from Germany.

- FOSM responsible to NHQ for all Class Authority and training functions in regard to submarines.

- FOSM under the administrative control of FOCINCEAST.

- FOSM to interact with both FOCs-in-C on all matters related to his charter of duties.

- Captain/Cmde (SM) on the East Coast and CO Virbahu to be separate entities.

FOSM's Interface with the Navy's Command and Control Organisation




capt/cmde (sm)
capt/cmde (sm)

CO Satavahana

Class S/Ms
Class S/Ms
Class S/M
CO Virbahu
Class S/Ms
Class S/Ms

9 SS
10 SS
12 SS

8 SS
11 SS

Submarine Rescue

Submarine Rescue Vessel (SRV) Nistar was acquired from Russia, commissioned in 1971 and based at Vishakhapatnam. She conducted the diving operation on the Pakistan Navy submarine, Ghazi, which sank outside Vishakhapatnam harbour in December 1971. From 1972 onwards, Nistar helped train the Navy's Deep Divers and Clearance Divers.

In 1975, a full-fledged medical organisation was sanctioned to provide cover for submarine rescue operations. In 1977, a safe 'Submarine Bottoming Area' was established off Vishakhapatnam to exercise mating trials between Nistar and submarines.

Between 1982 and 1987, contemporary European SRVs were evaluated for their suitability. A study was carried out of the utilization, on payment, of the US Navy's air-portable Deep Submergence Rescue Vessel (DSRV) rescue system. Each of these had pros and cons in Indian conditions.

The drought of the late 1980s and the ensuing shortage of resources led to the acquisition of a new SRV being postponed and the search for an interim solution.

In 1988, a vessel, which Mazagon Docks had built as a Diving Support Vessel for offshore oil exploration work became available for acquisition. It had a dynamic thruster facility and a recompression chamber. It was taken on dry charter and fitted with the diving bell and other essential rescue equipment removed from Nistar. After trials, she was commissioned as INS Nireekshak on 8 June 1989. Even though she was not a perfect SRV, she was better than the Nistar, which had become due for decommissioning. The roles envisaged for Nireekshak were:

- Facilitate rescue from a submarine in distress.

- Facilitate training of saturation divers.

Transformation of INS Satavahana into the School for Submarine Warfare

When INS Satavahana commissioned in 1974, the Submarine Training Wing and the Submarine Escape Training Facility formed part of the Integrated Type Training Establishment for the Russian acquisitions.

In 1986, when Southern Naval Command was assigned the task of 'Training', NHQ decided that submarine training would remain under Flag Officer Submarines.

To concentrate surface ship training in Cochin and to make space available in Satavahana for the training equipment of the newly inducted 877 EKM submarines, all the training equipment in the Surface Training Wing of Satavahana was carefully disconnected, bodily lifted into a landing ship and transported to Cochin where it was reinstalled and reconnected.

In 1989, Satavahana was designated as the School for Submarine Warfare.

By 1990, the EKM training equipment and the EKM command and control/ attack simulator had been installed.

Nuclear Propulsion for Submarines

“Nuclear propulsion in India was first mooted in 1967 when a naval officer and a BARC scientist prepared a feasibility report. A more detailed report was prepared in 1971 as the Committee of Secretaries felt that R&D on nuclear propulsion technology was inescapable if India was not to be left too far behind by the end of the century, when atomic energy would be a major source for both propulsion and energy requirements. A small nucleus of engineers was located in BARC as early as 1978.”

“Seeing the advent of nuclear propulsion in submarines of other navies, a study was undertaken by BARC to study a nuclear propulsion package for naval ships and submarines. A stage arose when it became necessary to train serving personnel in this very important area of propulsion technology.”

“The offer by the Soviet authorities of a 'nuclear powered submarine fleet' for the Indian Navy was made by Marshal Ogarkov during his visit to India in Apri1981. The Soviets offered to arrange a two-year training programme for Indian naval personnel, lease one nuclear submarine for five years for practical training and to render technical assistance for creating maintenance facilities in India for nuclear powered submarines. He added that the sale, as also assistance for designing and constructing nuclear‑powered submarines, could be taken up later.”

“An agreement was concluded with the Soviet Union and a team of officers under the supervision of Vice Admiral MK Roy was formed to steer the project. After a rigorous selection procedure, the first batch of the nuclear submarine crews, under the command of Captain S Daniel commenced their training in the USSR. The training was, perhaps, the most thorough and taxing course that any of the Indian submariners, most of whom had over a decade of submarining behind them, had ever undergone. They absorbed the new technology with professional aplomb.”

Between 1982 and 1986, the crew was trained. The base facilities were set up by 1987.

“On September 14, (1987) Admiral Roy, Vice Chief of the Eastern Naval Command, conveyed to me the pleasant news that the Government had finally decided to take the first nuclear-propelled submarine from the Soviet Union on lease, as purchase would entail acceptance of NPT conditions.

“The idea of acquiring a nuclear propelled submarine was floated by me as Defence Minister and after months of bargaining the Soviets agreed. A training programme was arranged for Indian sailors. I had visited the trainees in Leningrad and Riga. I was also happy that the lease amount charged by the Soviet Union was fairly reasonable. The nuclear propelled submarine had the advantage of remaining under water, which was not possible for the conventional submarines. It was also proposed at that time that a second nuclear-propelled submarine would be built in India. The Atomic Energy Commission experts were confident of producing an atomic power pack for the submarine.”

The Lease of Nuclear Submarine Chakra

On completion of the sea training commitment, the submarine was taken in hand to prepare her for the three-year period of lease.

The Utilization of Chakra

Chakra commissioned on 5 January 1988 and sailed for India on 15 January 1988. Except when transiting through shallow waters in the South China Sea, the Singapore Straits and the Strait of Malacca, her passage was submerged. Throughout her passage, she was tracked by Australian and American MRASW aircraft. The frigate, Dunagiri rendezvous’ her in the South China Sea to escort her homeward. On arrival Vishakhapatnam, she was received by Prime Minister, Rajiv Gandhi, the Defence Minister KC Pant and the CNS Admiral Nadkarni. After embarking, they were taken to sea for an outing.

During the three years of her lease, Chakra worked with both the Fleets off the east and west coasts of India.

Developments After 1990

Kalvari / Vela Class Submarines

The four submarines of the Kalvari class decommissioned between 1989 and 2003 (giving an average in-service life of 28 years). Of the four Vela class, two underwent 6-yearly refits between 1995 and 1999 and are stilin service. The other two decommissioned between 1997 and 2001.


On completion of the lease, Chakra sailed for Russia on 16 December 1990 and was thereafter decommissioned in January 1991.

Submarine Propulsion Batteries

The programme for the indigenization of propulsion batteries for the 877 EKM submarines that had been initiated in 1987 had not completed when the Soviet Union dissolved in 1991. By 1992, however, part supply of the first battery set for both EKM and SSK submarines started being received from Standard Batteries and Chloride India respectively. It took some years for indigenous batteries to completely replace those coming from Ukraine.

German HDW 1500 Shishumar Class (SSK) Submarines

SSK 3, Shalki, commissioned on 7 February 1992 and SSK 4, Shankul, commissioned on 28 May 1994. After Shankul's commissioning, the indigenous submarine construction programme at Mazagon Docks came to an end.

Overview of the Submarine Arm 1976-1990


KALVERI under refit in Russia Jan 75-Jul76 KURSURA continued torpedo firings for NST58
Under evaluation

Escape Training Tower commissioned

KHANDERI commenced refit in Visakhapatnam
Under evaluation
Indigenous production established of batteries for KALVARI and VELA class

KALVERI-NISTAR submarine escape trials
Under evaluation

KARANJ under refit in Russia Feb 78-Oct79
Under evaluation
Russian side mentions EKM

Under evaluation
Refit facilities established in Visakhapatnam First submarine docked in ND(V) for repairs

KHANDERI completed refit in Visakhapatnam KURSURA under refit in Russia Sep 80-Apr 82 VELA under refit in Russia Sep 80-Apr 82
Under evaluation
Russia side offers EKM

VAGIR under refit in Visakhapatnam Ju81-Oct 84
Contract signed in Dec 1981
Russian side repeats offer

VAGLI under refit in Russia Sep 82-Mar 84
Agreement signed Crew selected

SSKs 1 and 2 construction commenced in Germany
Indian side visits EKM
Crew commenced training in Russia

Kalveri under refit in Visakhapatnam Nov 84-Oct 88
SSKs 3 and 4 construction commenced in India


SSSKs 1 and 2 commissioned in Germany
EKM 1 commissioned
Crew completed training and returned to India

EKMs 2 and 3 commissioned
Crew standing by
Construction of VLF station commenced

KARANJ under refit in Visakhapatnam Sep 88-Dec 90
Indigenous production established of batteries for SSK and EKM submarines
EKMs 4,5 & 6 commissioned
CHAKRA commissioned

KARANJ under refit in in Visakhapatnam
EKM 7 commissioned
Diving Support VesseNIREEKSHAK chartered as interim Rescue Vessel

KARANJ under refit in Visakhapatnam
EKM 8 commissioned
VLF station commissioned

Battery Commissioning Facility estalished in Bombay

CHAKRA returned to Russia

SSK 3 commissioned in India


SSK 4 commissioned in India


By any yardstick, the achievements of the Submarine Arm were remarkable. In the thirty years from 1962 when, starting from scratch, the very first submariners underwent training in the British Navy, unti1991, the Navy inducted eighteen of the latest conventional submarines of their time, sixteen from Russia and two from Germany (with two more German submarines under construction in Bombay) and also manned, operated and maintained a missile-firing nuclear propelled submarine for three years, apart from setting up submarine infrastructure facilities at Bombay and Vishakhapatnam.

The difficulties encountered in attracting into, and retaining in, the submarine cadre sufficient technical personnel (officers, artificers and non-artificers), the difficulties in refitting submarines and the difficulties in coping with the ripple effects of inadequate air conditioning in tropical conditions were tackled with the typically Indian tenacity to keep things going until solutions were found.

The best features of four distinct traditions (three pertaining to conventional submarines - the British tradition in the early 1960s, the Russian tradition in the 1970s and 1980s, the German tradition in the 1980s and the fourth tradition in the 1980s pertaining to Russian nuclear submarines) were adapted and synthesized into a tradition uniquely appropriate to Indian conditions and climate.

As in the case of warships, Admirals Gorshkov and Chernavin of the Soviet Navy did their utmost to help the Submarine Arm. The assistance of the Soviet and German governments and their navies was very valuable. Most valuable of always the understanding of the Indian Government of the future potential of the Navy's Submarine Arm.

Submariners have always been an elite fraternity. The unique characteristic of submariners in every Navy, and one which India's submariners have nurtured with the utmost care, is the awareness that when dived, the safety of their submarine depends on every member of the crew doing everything right. Each one of the crew knows that the lives of all depend upon each one doing the right thing. Mishaps have been manageable and non-catastrophic.

Submariners also have unique customs. Writing in the Navy Foundation's annual magazine Quarterdeck 1987, Commodore (later Rear Admiral) KR Menon said:

“Submarines may change, but customs and traditions don't. Submarines still leave homeport for change of base with a band on the jetty, and come back to be received by the Captain SM and the traditional cake.”

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