Submarine Support Equipment

LI 0941 - Submarine Support Equipment is a Navy budget line item that supports the modernization, sustainment, and replacement of critical support equipment for all classes of nuclear submarines (SSN/SSBN/SSGN) and associated land-based facilities. The overarching goal is to ensure the operational readiness, safety, and stealth capabilities of the submarine fleet through targeted investments in hardware, software, and infrastructure. This line item addresses obsolescence, reliability, and capability gaps identified through operational experience and technical studies, such as the SIB-25 study, which has influenced funding increases for FY 2026.

SSN Class Component Upgrades focus on technical refreshes and upgrades for submarine hardware and software systems. These upgrades include procurement and installation of digital voltage regulators, integrated communications system upgrades, shock modifications for diesel generator control panels, and improvements to battery management and machinery control systems. The objective is to mitigate obsolescence, improve reliability, and ensure continued supportability of critical shipboard systems. Funding also supports production engineering and installation planning to align upgrades with scheduled maintenance availabilities.

Facilities/Lab Upgrades provide for the procurement of equipment and materials to implement, sustain, and modernize high-priority submarine signature measurement programs. This includes investments in acoustic range equipment, underwater electromagnetic range equipment, and the construction of new measurement facilities such as the Pacific Deep Electromagnetic Research Measurement Array at PMRF Hawaii. These upgrades are essential for measuring submarine acoustic and electromagnetic signatures, supporting fleet stealth, and validating platform requirements in response to evolving threats and operational needs.

Weapons Handling Systems funds modifications and improvements to weapons launching, stowage, and shipping systems for SSN 688, SSN 774, and SSN 21 class submarines. Objectives include addressing reliability, maintainability, and safety issues, as well as tactical improvements based on operational feedback. Projects include tech refreshes for weapons launch consoles, fiber optic interface upgrades for torpedo tubes to support new payloads, and electromechanical power conditioner/controller replacements to ensure compatibility with future combat system upgrades.

VA Class SOF Modifications and Dry Deck Shelter Modernization support the unique operational requirements of Special Operating Forces designated submarines. Funding is used for the procurement and installation of SOF-specific system components, Diver Oxygen Treatment Systems, Lockout Trunk certifications, and modernization of Dry Deck Shelters in partnership with USSOCOM. These efforts ensure the fleet's ability to support current and future Naval Special Warfare payloads and maintain SOF delivery capabilities.

AUKUS Submarine Rotational Forces West (SRF-W) sub-line funds the procurement and installation of C4I systems necessary for supporting U.S. submarine operations in Australia. This includes IT infrastructure such as NIPR, SIPR, NNPI, SYLAN, SECNET, and telephony systems, which are critical for establishing normal operations and achieving Initial and Full Operational Capability milestones for SRF-W. Costs are primarily one-time procurement expenses based on similar recent installations.

Acoustic Superiority Machinery Alterations are based on the South Dakota Improvement Program and fund the backfit of advanced acoustic superiority modifications on selected submarines. These alterations improve stealth and operational effectiveness by implementing machinery changes and sensor upgrades developed for the USS SOUTH DAKOTA. The program includes material procurement, design and development, installation planning, and execution. The second component of the acoustic superiority program is funded under a separate line item.