India is preparing to take a major step forward in its underwater combat capabilities. The domestically engineered Takshak heavyweight torpedo is scheduled to commence user-evaluation trials (UET) from the Indian Navy's Kalvari-class submarine fleet in late 2026.
This crucial testing phase is timed to align with the ongoing modernisation and refit schedule of these submarines, paving the way for a planned live warhead test in 2027.
Spearheaded by the Defence Research and Development Organisation (DRDO)—specifically its Naval Science and Technological Laboratory (NSTL)—the Takshak is a next-generation Electric Heavyweight Torpedo (EHWT).
Designed as an advanced, submarine-launched successor to the older Varunastra, the Takshak utilises a modern electric battery system for propulsion.
At 6.4 metres in length, it is specifically optimised to fit within submarine launch tubes.
The weapon also boasts a Ring Laser Gyro Inertial Navigation System (RLG INS) alongside indigenous NavIC satellite guidance, ensuring highly precise targeting against enemy submarines and surface warships.
A pivotal moment for the programme occurred in December 2024 when the Ministry of Defence finalised an ₹877 crore agreement with France's Naval Group.
This contract facilitates the integration of the torpedo’s advanced guidance software with the SUBTICS Combat Management System aboard the Kalvari-class (Scorpene-class) submarines, which were built in India by Mazagon Dock Shipbuilders Limited (MDL).
Linking Takshak to SUBTICS is critical, as it allows the submarine’s central computer to seamlessly manage target tracking, sensors, and weapon deployment.
Currently, the lead vessel, INS Kalvari, is undergoing its first major refit.
Alongside the installation of an indigenous Air Independent Propulsion (AIP) module, the submarine is being fitted with the necessary hardware for the torpedo's unique "swim-out" launch mechanism.
This specialised method allows the torpedo to quietly swim out of its tube under its own power, rather than being forcefully ejected by loud bursts of compressed air, thereby preserving the submarine's vital acoustic stealth.
Before heading out to the open ocean, the Takshak will undergo rigorous dry and wet harbour trials while the submarine remains securely docked.
These preliminary tests are essential to confirm that the weapon can exit the launch tube smoothly without posing any risk to the vessel's hull, delicate sensors, or internal systems.
Once harbour testing is cleared, dynamic sea trials will begin in late 2026. During this phase, the submarine will deploy the weapon under various tactical conditions, at different depths, and at varying speeds.
A primary focus of these sea trials will be validating the Takshak's state-of-the-art fibre-optic wire guidance system.
Unlike older "fire-and-forget" torpedoes, this continuous physical data link allows the submarine's sonar operators to send real-time course corrections directly to the torpedo as the battlefield changes.
Maintaining the physical integrity of this fragile fibre-optic cable during high-speed underwater manoeuvres is one of the most significant engineering challenges the Navy will test.
Provided these dynamic evaluations proceed without issue, a fully armed Takshak will be fired at a decommissioned target ship or underwater structure in 2027.
This live warhead test will serve as the final validation of the weapon's lethality and stealth before its official induction into the naval fleet.
