OVERVIEW: The SSN 671 *Narwhal* is a submarine operated by the United States Navy.

DETAILS: The *Narwhal* (SSN 671) represents a unique design evolution within the US Navy’s submarine force. Commissioned in 1996, it is probable the data references a modernization or refit. The initial *Narwhal*, commissioned in 1969, was designed as a test platform for advanced nuclear propulsion technology, specifically a natural circulation reactor, intended to reduce noise and improve stealth characteristics. While the original *Narwhal* served for over three decades, the timeline suggests the SSN 671 as referenced is a later unit, possibly a test platform, or a designation applied to a modified or rebuilt vessel utilizing legacy components with significant system upgrades. The design, regardless of the hull it occupies, reflects a focus on acoustic superiority and advanced sensor integration, crucial for Cold War and post-Cold War submarine operations. The comparatively smaller displacement for a nuclear-powered submarine may also imply a focus on shallow water or littoral operations.

The *Narwhal's* primary role is likely anti-submarine warfare (ASW), although anti-surface warfare (ASuW) and intelligence, surveillance, and reconnaissance (ISR) missions would also be within its capabilities. Given the vessel's sensor suite, a strong emphasis is placed on detecting and tracking hostile submarines in both deep ocean and potentially more challenging littoral environments. The 533mm torpedo tubes are capable of launching a variety of modern torpedoes, enabling effective engagement of enemy submarines and surface combatants. The presence of the 3-inch signal ejector suggests the capability to deploy countermeasures or conduct covert communication. The electronic warfare support measures (ESM) systems, such as the AN/WLR-9A and AN/BRD-6, allow the submarine to identify and classify enemy radar emissions, providing valuable situational awareness.

The sensor suite aboard the *Narwhal* indicates a strong focus on situational awareness. The AN/BQS-14 provides close-range, high-frequency active sonar capabilities, useful for mine detection and navigation in confined waters. The AN/BPS-14 likely serves as a radar intercept receiver, alerting the submarine to the presence of potentially hostile radar transmissions. The installation of the AN/TB-23/BQ towed array allows for long-range passive acoustic detection and classification, while the AN/TB-16B acts as a backup or provides a different frequency range for acoustic surveillance. The AN/WLQ-4 Sea Nymph serves as an advanced electronic surveillance system, intercepting and analyzing a broad spectrum of electronic signals. The NA-25X radar/IR system adds surface search and limited air search capability. The dual periscope configuration, including a low-light television (LLTV) enhanced periscope, further enhances situational awareness and target identification at periscope depth.

SPECIFICATION: Length: 96.0 m || Beam: 9.7 m || Draft: 8.8 m || Disp: 5027 t

SENSORS: AN/WLR-9A || AN/WLQ-4 Sea Nymph || AN/TB-23/BQ || AN/BQS-14 || AN/BPS-14 || AN/TB-16B || NA-25X [Radar/IR] || AN/BRD-6 || Generic Submarine Periscope, Optical || Generic Submarine Periscope, LLTV

ARMAMENT: 533mm Mk67 TT || 3-inch Signal Ejector