A torpedo's looming endurance test
The Varunastra is being developed for range and speed to take on future submarine threats in the region
 "Satarupa Bhattacharjya")
 "An advanced heavyweight torpedo, Varunastra, weighing around 1850 kilograms and has acoustic-homing abilities which enables targeting of silent submarines (Photo: Indian Navy)")
The advanced heavyweight torpedo, Varunastra, which weighs around 1,850 kilograms and has acoustic-homing abilities, can target silent submarines (Photo: Indian Navy)
The Varunastra, named after the sea god in Hindu mythology, is an advanced heavyweight torpedo that is fitted on Indian warships.
The electrically propelled torpedo can be fired from ships at submarines, both in deep and shallow waters.
The torpedo weighs around 1,850 kilogrammes (kg) and can reach depths of 600 metres while travelling between 40 and 50 knots. It has a range of around 40 kilometres. It was inducted in 2016 after being designed by the Defence Research and Development Organisation (DRDO), the government agency, as part of the Indian Navy’s underwater weapons suite.
It is being developed further for range, speed, and to enable it with artificial intelligence. The torpedo is likely to be deployed on all future anti-submarine ships in India.
“It remains the weapon of choice,” a former high official of the Indian Navy said, adding that the torpedo’s role in warfare will continue to be crucial, especially with submarine-based threats expected to rise in the future.
 "Pakistan Navy's submarine sails past a naval sailing ship during the sea phase of its 9th Multinational Maritime Exercise AMAN-25 in the Arabian Sea near Karachi on February 10 (Photo: Reuters)")
Increasing the torpedo’s “great endurance” will boost the Navy’s overall weapons capability, a current source said. A combat variant of the Varunastra was successfully test-fired at sea, using a live warhead, in 2023.
“There are various ways of initiating the explosion,” the Navy source said, without providing details.
The warhead is thought to be at least 250 kg. The weapon itself was 1,500 kg in the 2016 version.
The torpedo’s acoustic-homing ability makes it capable of targeting silent submarines, according to Bharat Dynamics Ltd, the public company that makes it. The first batch of 73 torpedoes cost the Navy ₹8,760 crore ($987,153), a previous media statement by the government said. Many more were ordered after that.
In March, the Defence Acquisition Council cleared the “acceptance of necessity” for a newer batch of the ship-launched variant of the Varunastra. Trials for a submarine-launched variant are ongoing.
Pakistan is buying diesel-electric attack submarines from China. Based on the Chinese Navy’s Yuan-class platform, three such submarines have been delivered until August, and one is awaited. Four others will be reportedly made in Pakistan under a transfer-of-technology arrangement.
These purchases will affect the regional power dynamics, according to defence analysts.
With such scenarios in mind, the DRDO’s naval design unit and the Indian Navy have increased the focus on developing advanced weapons; underwater decoys, including anti-torpedo; water mines (different kinds such as moored and ground); ship-fire control systems; sonars; supportive marine vehicles; and stealth technology for naval platforms.
Written By
Satarupa Bhattacharjya
 "Satarupa Bhattacharjya")
First Published: Oct 07 2025 | 12:34 PM IST
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