Surface Ship Torpedo Defense

Abstract

The Surface Ship Torpedo Defense (SSTD) program provides a detect-to-engage layered torpedo defense capability. The four (4) major efforts that comprise SSTD are the AN/SLQ-25 (NIXIE) system, Torpedo Warning System (TWS), the Countermeasure Anti-Torpedo (CAT), and Acoustic Device Countermeasure (Surface ADC MK2). The Anti-Torpedo Torpedo Defense System (ATTDS) is comprised of TWS and CAT. The ATTDS provides a hard kill torpedo defensive capability on High Value Units (HVU's). The SSTD program developed and fielded five (5) ATTDS Engineering Design Models (EDMs) systems on CVNs. Each EDM system is one (1) TWS with a load out of a maximum of eight (8) CATs. In FY20, the ATTDS program commenced sundown efforts to return the five (5) CVNs to their original configuration. Two (2) system removals completed in FY22, with one (1) more completed in FY23. FY23 and FY24 funding will provide minimal support to the 2 remaining CVN installations with system preservation the primary focus. FY 24 funding will also support beginning Research, Development, Test & Evaluation (RDT&E) planning efforts to develop and incorporate TWS capabilities into the AN/SLQ-25 (Nixie) via Tech Insertions (TIs). FY25 funding is to complete removal of ATTDS and restore NIXIE on the final two CVNs with the system. The funding will also be used to begin development of Torpedo Detection, Classification and Localization (TDCL) capability in support of torpedo defense requirements. Minimal funds will be used to support the remaining ATTDS systems until removal. Research and development of new technologies and capabilities for torpedo defense initiated under the Future Naval Capabilities (FNC), Small Business and Innovative Research (SBIR), and/or other Research, Development, Test & Evaluation (RDT&E) initiatives are evaluated to determine their effectiveness and impact on improving ship survivability. Evaluations of new and emerging torpedo defense hardware and software in representative acoustic environments, against projected threats using both digital and hardware-in-the-loop simulations will be performed. The potential hardware and software will be considered for integration into the modular and Commercial-Off-The-Shelf (COTS)-based design of AN/SLQ-25E, which allows for future capability growth to outpace the threat in torpedo defense. Two (2) FY22 Congressional adds support research and development of new torpedo defense capabilities for insertion into the 25E effort, as well as improve the safety and reliability of the 25E towed winch and reel system.

Document Details

• Document Type: R2 Budgetary Justification
• Publication Date: Oct 01, 2025
• Source ID: 0603506N_4_1319_PB_2025
• Change Summary Explanation: FY2023 decrease from FY2024 position of -$0.019 million due to SBIR reduction ($0.012 million) and Cancelled Accounts reduction ($0.007 million). FY2025 net decreased from FY2024 position by -$0.122M, which includes: -$0.158 million due to program adjustments and an increase in miscellaneous adjustments of +$0.036 million.
• Service Agency Name: Navy

Entities

Organizations

• United States Navy

Tags

Readers

• Naval Mine Countermeasure Systems Development.