The recent commissioning of INS Vishakapatnam, and INS Vela, the first of Project 15B reduced signature destroyers and the fourth Scorpene class submarine respectively, threw into sharp relief, the Navy’s sincere and sustained efforts into developing, designing and building warships in India – creating a truly state of the art fleet from relatively humble beginnings. Indeed, many wondered how the Navy could pull off such a feat, building extremely complex platforms such as aircraft carriers and stealthy warships while the Indian Army and Air Force have lagged so behind.
A worthy question, and one that inspired this article – the journey, as we shall discover has taken over 70 years. This article is only part one, of a three-part series – and will cover three major projects taken up by the Navy in the very beginning of its journey to self reliance.
The Beginning – LEANDERs
The Navy’s path to indigenization began with the setting up of the Directorate of Naval Construction (DNC) in the 1950s. The organization was set up for handling all aspects of naval shipbuilding – policy, planning, designing, building and maintenance.
The first major program to build warships in India was the Leander frigate project, which was started in 1964 when agreements were concluded with Britain to enable Indian Leander frigates to come on line in the same timeframe as the Royal Navy’s ships.
Even with these ‘licensed produced’ ships, the IN on its own initiative began programs to start modifying and upgrading the ships, from the second of the class onwards, and as we shall see the last two ships were almost entirely new ships.
The first frigate was the Nilgiri, whose keel was laid down in October, 1966. And since there was a slight delay between the construction of the first and the order for the second, the Navy took the time to study various systems that could be upgraded.
As a result, the Navy identified Signaal, a Dutch company and tied up with NEVESBU, the Dutch Warship Design Bureau – which provided Digital Electronic Systems compared to the original Analog Electronic Systems that came with Nilgiri. These systems, however needed significant modifications to the hull and superstructure of the ships, which the DNC undertook on its own.
Subsequently, all remainder ships of the Nilgiri class received these Signaal sensors, and control systems, better radar, modified sonar and two Seacat missile launchers instead of one.
The second, third and fourth frigates of the class – Himgiri, Udaygiri and Dunagiri focused on reducing build times and improving the confidence of all associated with the project – including the manufacturers across the nation supplying all systems.
By 1973, experience had been built up in the navy from operating the first Leander, the Nilgiri, as well as the recently acquired British built SeaKing Anti-Submarine Warfare (ASW) helicopters. Naval HQ felt that given the growing threat of modern French submarines being acquired by Pakistan, it would perhaps be prudent for the 5th and 6th Leanders to have improved ASW capabilities and for Directorate of Naval Design to study if the last two ships could operate the bigger 10 tonne Seakings from their helo decks – which originally had been designed for light utility helicopters – the Aleoutte IIIs (Chetaks).
Thus it was decided to suitably modify the last two ships. A telescopic folding hangar was installed on the aft helo deck to accommodate the much bigger SeaKing helos, and the anti-submarine mortar installed there was removed. To make the vessels first rate ASW ships, the following modifications were done:
- Swedish Bofors SR 375 twin ASW rocket launchers were installed in lieu of the now replaced British Mortar mk10.
- Two sided mounted torpedo tube launchers were installed with the then latest Italian Whitehead A244 homing torpedoes.
- New Graseby 184 Solid state search sonar
- French Thompson CSF Solid State search and attack sonar.
- Locally made fire control computer to direct the new SR 375 rocket launcher and the torpedo tubes.
- Latest Italian Electronic Warfare systems.
It was to this revised design and layout that the 5th and 6th Leanders were built, that is – Taragiri and Vindhyagiri.
The Leander project was the first major milestone in the Indian Navy, and brought with it several key developments that paved the way for future successes.
- Pvt industries and govt PSUs alike developed the technological know how to make various sub components of a warship, such as radars, sensors (BEL) weapon systems, propulsion (BHEL), gearbox and propulsion shaft and so on.
- Mazgaon Dockyards gained crucial first hand experience at building a modern complex frigate with all associated difficulties
- The Directorate of Naval Design and the Navy as a whole got some much needed experience with modifying such a large ship – and the confidence gained from successful executions to pursue far more complicated ships.
The Pioneers – Project 16 – the Godavaris
In 1972, after the conclusion of the 1971 Indo Pak war, and before the commissioning of INS Nilgiri, Naval HQ had already drawn up requirements for the next frigates – taking into account the recent war and its lessons. Accordingly the following requirements were drawn up:
- Russian weapon suite as found on the Nanuchka class corvettes (CIWS, main gun, anti ship and AD missiles) and primary air and surface radar of the Kashin (Rajput class) destroyers.
- Two Seaking helicopters to be carried onboard – one of the earliest (if not the first) ship class to carry 2 10 tonne helos at a weight of 4000 tonnes.
- The latest Indian APSOH sonar (more on this later in this article)
- A mix of Soviet, Indian and Italian radas, CAAIS and EW systems.
Additionally, the Navy wanted to built the ship with Gas Turbine propulsion but since it was a relatively new technology, it was decided to retain the Leanders’ BHEL built Bhopal Steam Turbines.
Initially, the DND felt that the Leander design could be modified to fit the Navy’s requirements, but given that the former was a purely anti submarine/air defence warship, it would not do, and thus, a new design was built from scratch.
While the Leanders were roughly 3000 tonne warships, the new frigates would be 3600 tonnes and represented a significant challenge for the IN’s budding design team. Thus, Captain NS Mohan Ram, who headed the design team for Project 16, felt that it would be prudent to retain all systems possible from the Leanders and go for fresh design only where necessary. And thus, while the DND estimated that the ship would need about 40000 HP of total engine power, he decided to retain 30000 HP of the two Bhopal Steam Turbines of the Leanders, prepared to lose a knot or two of speed in favour of simplified build and reduced time.
However, much to everyone’s surprise multiple calculations showed that the Godavaris rather than losing speed (compared to the Leanders) ended up gaining speed!
The Navy’s design team had hit upon a surprising natural phenomenon, and one that the DND has tried to maximise since.
It was found that at lower speeds, the resistance to a ship’s motion is primarily due to friction, and that at higher speeds, the speed was largely held back by the hull’s interaction with the waves made by the ship. If the two waves created by the stern and bow of the ship resulted in a crest at the rear, then the resistance would be low, but if it created a trough, then friction would be higher. The Godavari’s excellent hull design resulted in a crest, and thus, she gained better speed at less power capacity.
Thus, the Navy’s decision to use the same power plant, shafts, transmission and even propellers (all of which were being built in the nation) saved a lot of time and made things much simpler for Mazgaon dockyards.
Another unique problem arose with the mix of weapons and systems from so many sources. Soviet ships use 380 volts, 3 phase, 50 cycle power supply while Western ships use 440 volts, 3 phase, 60 cycle power. This caused no small amount of confusion and head scratching. The Navy decided however to maintain two different power systems – with the main power generation (tied to the British design propulsion) was kept at 440 V, 3 Ph, 60 Hz while suitable alternators were installed to convert to 380 V, 50 Hz for the Soviet weapons and sensors.
The first ship, Godavari was built and commissioned in 1983, Ganga in 1985 and Gomati in 1988. Gomati remains in service today, but not for long.
APSOH – An Indian SONAR for the Indian Ocean
Parallel to the frigates and other warships under construction, the Navy in its earliest days sought to bring about indigenous solutions in another crucial area of naval warfare. SONARs – and their use in anti submarine operations.
The first attempt ended in a disaster. Lt VK Jain was working with Bhabha Atomic Research Centre’s team to improve signal processing of the Sonar 170B found on the Type 14 ASW frigates in service, when war broke out in December, 1971. Lt Jain was onboard INS Khukri, in the sonar dome, working with his modified kit when the ship was struck by the Pakistani submarine Hangor and sunk, Lt Jain going down with the ship.
Immediately after this incident, Lt A Paulraj was assigned the task of improving the navy’s sonars and working with a team from IIT Delhi. By 1972-73 the modified signal processing unit for the old British Sonar 170Bs had been developed and deployed on INS Kuthar for sea trials – and showed immense promise.
Subsequently, the Navy green lit the development of an entirely de novo design sonar – to be built by BEL under Lt Paulraj’s leadership. By 1979, this new Sonar was ready, and trialled aboard INS Himgiri (the second Leander), and proved to be entirely successful. Being built from the ground up to work in the tough oceanic conditions of the Indian Ocean, no other sonar works as well as India’s own APSOH series.
APSOH, and its successors – HUMSA, HUMSANG, remain to this day the primary sonars onboard all warships of the Indian Navy, and have also seen success in the export market.