OVERVIEW: The SSBN 640 Benjamin Franklin [Improved Lafayette Class] is a ballistic missile submarine operated by the United States Navy. Commissioned in 1981, she represents an improved variant of the Lafayette-class submarine, incorporating updated sensor suites and weapon systems.

DETAILS: The Benjamin Franklin, as an Improved Lafayette-class boat, represents a crucial evolution in the US Navy's strategic deterrent force. The Lafayette class itself was designed in the early 1960s to carry the Polaris A3 SLBM. The Improved Lafayette variant, which includes the Benjamin Franklin, were designed as the lead class for the Trident I (C4) missile, and represented a significant upgrade in capabilities, offering increased range and payload capacity compared to earlier systems. These submarines were intended to maintain a credible second-strike capability, ensuring nuclear deterrence during the Cold War. The design philosophy emphasized stealth, reliability, and survivability in the face of increasingly sophisticated Soviet anti-submarine warfare (ASW) capabilities. The class received extensive refits during the 1980s.

The primary role of the Benjamin Franklin was strategic deterrence, achieved through the deployment of Trident C4 Submarine Launched Ballistic Missiles (SLBMs). While primarily focused on strategic deterrence, the vessel also maintained a limited anti-submarine warfare (ASW) capability for self-defense and escort duties. The submarine would have operated in the deep ocean, relying on stealth and advanced sensors to avoid detection. Her patrol routes would have been designed to maximize survivability and ensure the ability to launch a retaliatory strike if necessary. The 533mm torpedo tubes allowed for engagement of enemy submarines and surface vessels in self-defense scenarios.

The Benjamin Franklin's sensor suite provided comprehensive situational awareness. The AN/BQS-4 bow-mounted sonar served as the primary active/passive detection system. The AN/BQR-7, AN/BQR-15, AN/BQR-19, and AN/BQR-21 passive sonar arrays offered enhanced long-range detection and classification capabilities. The AN/WLR-8(V)2 and AN/WLR-9 electronic support measures (ESM) systems provided early warning of radar emissions from enemy ships and aircraft. The AN/BPS-15A surface search radar allowed for navigation and detection of surface contacts when operating near the surface. The submarine periscopes, one optical and one LLTV (Low Light Television) equipped, enabled visual observation. The installation of the CSA Mk1 FED [Mk139] countermeasures launcher provided a soft-kill defense against incoming torpedoes. The 533mm Mk65 torpedoes offered a potent offensive and defensive capability against submarines and surface vessels.

SPECIFICATION: Length: 129.6 m || Beam: 10.0 m || Draft: 9.6 m || Disp: 7370 t

SENSORS: AN/WLR-8(V)2 || AN/BQR-15 || AN/BPS-15A || AN/BQS-4 || AN/BQR-7 || AN/BQR-21 || AN/BQR-19 || AN/WLR-9 || Generic Submarine Periscope, Optical || Generic Submarine Periscope, LLTV

ARMAMENT: Trident C4 || 533mm Mk65 TT || 533mm Mk65 TT || 3-inch Signal Ejector || CSA Mk1 FED [Mk139]