Advanced Lightweight Torpedo being launched from Ship-borne Launcher

A self-reliant and strong navy to protect India’s maritime interests is central to our national policy. DRDO is involved in design and development of highly complex and technologically intensive naval warfare systems to meet the requirements of the Indian navy.

Advanced Lightweight Torpedo (ALWT) is an anti-submarine torpedo launched from ship, helicopter or from a fixed wing aircraft. The presence of enemy target is detected by the sonar on-board a ship or an aircraft. Based on target parameters estimated by the sonar and Fire Control System, torpedo is fired with a few preset parameters to ensure that the weapon is in most favourable position to acquire the target, home in and destroy it. As submarine can change course and depth during its evasive manoeuvre, the weapon is to be guided in both horizontal and vertical planes to attack the target. 

Lightweight torpedoes around the world conform to a diameter of 324 mm, an overall length of 2.5-3 m and weigh around 300 kg. ALWT has an operational depth of 600 m, is capable of being launched from lightweight torpedo tubes of IN ships, Advanced Light Helicopter and Sea King 42B helicopters of the IN.

The main sub-systems of ALWT are classified into mechanical and electronics sub-systems:

Mechanical Sub-Systems Comprise: 

Nose Cone & SPU Shells
Exercise Head
Inertial Navigation System & Battery Shells
Rear Section
Sealing System
Propulsion Electric drive and motor
Pump Jet Propeller (PJP)
Actuation System
Integrated Pneumatic Recovery System (IPRS) and Sunken Torpedo Recovery System (STRS)
Flight in Air Mechanism (FIAM) including parachute, torpedo release mechanism etc.

Electronic Systems Comprise:

Homing system (Acoustic Sensors, Front End Electronics and Signal Processing System)
On-board Computer
Integrated Instrumentation and Recording System (IIRS) and Recovery Systems
Inertial Navigation System (INS) / Attitude & Heading Reference System (AHRS)
Battery Systems and Scoop Bulk Head
Power Electronic Drive and BLDC Motor
Actuation System
Presetter System


Naval weapons and platforms operate under entirely different environmental conditions. And focusing on this aspect, different set of technologies, which require integration of multi disciplinary technologies was developed. ALWT has completed 32 technical trials at sea and is gearing up for User Evaluation Trials.

DRDO Newsletter