OVERVIEW: The Yu-3 is a Chinese submarine-launched heavyweight torpedo introduced in 1984, using passive acoustic homing for anti-submarine warfare. It was the first domestically developed guided ASW torpedo fielded by the PLA Navy.

DETAILS: "Yu" (鱼) is the Chinese term for "fish", used in torpedo designations; "3" denotes its position in the development sequence. Development began in the mid-1960s under the 705th Research Institute and faced delays until successful trials led to acceptance into service in 1984. The Yu-3 uses an electric propulsion system powered by silver-zinc batteries and operates at moderate depth and speed for its class. It was equipped with a passive acoustic seeker and designed to home in on submarine noise signatures without wire guidance or terminal activation modes.

TYPE: Heavyweight Anti-Submarine Warfare (ASW) Torpedo

FUNCTION: The Yu-3 is launched from submarines and uses a passive acoustic homing system to track and engage enemy submarines. It is effective against targets emitting detectable noise and is designed for mid-range underwater engagements.

NOTE:
IOC: 1984 (Yu-3)
Manufacturer: China (705th Research Institute / CSIC)
Operators: China
Platforms: Type 035 Ming-class submarine, Type 091 Han-class submarine

SOURCE:
Wikipedia: https://en.wikipedia.org/wiki/Yu-3_torpedo ; Friedman, The Naval Institute Guide to World Naval Weapon Systems ; Military Periscope: https://www.militaryperiscope.com/weapons/naval-minestorpedoes/torpedoes/yu-3-heavyweight-torpedo/overview/ ; China Defense Today: https://www.sinodefence.com/navy/weapon/yu3.asp