OVERVIEW: The Spearfish Mod 1 is a heavyweight, wire-guided, submarine-launched torpedo upgrade delivered by the UK Royal Navy starting in 2021. It features enhanced homing, a fibre-optic datalink, and a safer propulsion and warhead system.

DETAILS: Spearfish is the heavyweight torpedo developed by BAE Systems Underwater Systems (originally GEC‑Marconi) for British submarines. Mod 1 is the modernized version of Mod 0 (1994 entry‑into‑service) incorporating a fully digital weapon architecture, a new insensitive-munitions warhead by TDW, single-fuel Otto II propulsion replacing the dual-fuel Otto/HAP, and a high-bandwidth fibre‑optic wire‑guidance link for mid-course control. These improvements significantly enhance automated target tracking, resistance to countermeasures, maintainability via modular components, and operator safety. Initial Operating Capability was declared in May 2021 after successful firings from Trafalgar‑class and Astute‑class boats; Vanguard‑class SSBN trials completed by mid‑2024 .

TYPE: Heavyweight Dual‑Purpose Guided Torpedo

FUNCTION: Launched from 533 mm submarine tubes, Spearfish Mod 1 uses a fibre‑optic link for real‑time mid-course command, transitioning to autonomous active/passive acoustic homing to engage both submarines and surface ships. Its high-speed gas-turbine pump‑jet and advanced seeker make it effective in deep, littoral, and countermeasure-heavy environments.

NOTE:
IOC: 2021 (Mod 1); Mod 0 IOC 1994
Manufacturer: United Kingdom (BAE Systems Underwater Systems)
Operators: United Kingdom
Platforms: Trafalgar‑class SSN, Astute‑class SSN, Vanguard‑class SSBN

SOURCE: U.K. Ministry of Defence / BAE Systems Spearfish Upgrade programme ; Jane’s Defence News ; Army Recognition : https://armyrecognition.com/news/navy-news/2024/british_navy_successfully_tests_spearfish_mod_1 ; Navy Lookout Spearfish Mod 1 in service ; Jane’s: UK declares IOC for Spearfish Mod 1 բաժhttps://www.janes.com/osint-insights/defence-news/uk-declares-ioc-for-spearfish-mod-1