OVERVIEW: The E18 is a French electric, passive acoustic-homing anti-ship torpedo, designed for short-range engagements. It was exported in the 1980s for use aboard conventional submarines with 533 mm tubes.

DETAILS: “E” denotes France’s series of electric torpedoes. The E18 was carried as standard torpedo armament in exported Agosta-class submarines. Spain’s S 71 Galerna (Agosta) and Pakistan’s S 135 Hashmat were equipped with E18 torpedoes alongside other French torpedoes like F17 and L5. It is powered by electric propulsion (nickel–cadmium battery) and uses passive acoustic homing against surface vessels.

TYPE: Heavyweight Passive Acoustic Anti‑Ship Torpedo

FUNCTION: Launched from submarines, the E18 uses passive acoustic homing to detect and engage surface ship targets. Designed for short-range combat, it runs a stealthy electric-powered course towards the acoustic signature of ships.

NOTE:
IOC: 1980s (export program)
Manufacturer: France (originally Alcatel/ACAN under DCN)
Operators: Spain, Pakistan
Platforms: S 71 Galerna (Spain, Agosta) and S 135 Hashmat (Pakistan, Agosta) 

SOURCE:
Naval-encyclopedia.com “Classe Agosta”: https://naval-encyclopedia.com/cold-war/france/agosta-class-submarine.php ; frwiki “Classe Agosta”: https://fr-academic.com/dic.nsf/frwiki/62121 ; SIPRI export data via Pakistan Defence forum: https://defence.pk/threads/torpedoes-of-pak-navy.453521