Benjamin Franklin-class (SSBN-640)

Summary

Description

The Benjamin Franklin-class submarine was an evolutionary upgrade from the earlier James Madison class, operating in the United States Navy from the 1960s to the 2000s. These submarines were quieter and featured improvements that warranted classification as a distinct class. They were part of the "41 for Freedom," the Navy's main nuclear deterrent force into the late 1980s. The class also includes the USS George C. Marshall, which initiated the re-engineered 640 class, built in compliance with new safety standards prompted by the loss of USS Thresher. The initial boats in the class underwent retrofitting to meet these SUBSAFE requirements.

Designed initially to carry the Polaris A-3 ballistic missile, these submarines were converted in the early 1970s to accommodate the Poseidon C-3 missile. In the late 1970s and early 1980s, a subset of six boats was further upgraded to carry the Trident I (C-4) missile. The design of the Benjamin Franklin-class submarines incorporated equipment similar to the Sturgeon-class attack submarines, unlike previous ballistic missile submarines. Characteristic of this class was the positioning of the fairwater planes halfway up the sail, a feature that distinguished them from the Lafayettes and James Madisons.

During their operational history, two submarines were converted to support special operations, capable of delivering up to 66 SEALs or other Special Operations Forces. To comply with the constraints set by the SALT II treaty and make room for the incoming Ohio-class ballistic missile submarines, the missile tubes of Kamehameha and James K. Polk were deactivated and the vessels were repurposed as special operations attack submarines, equipped with dry deck shelters for SEAL Delivery Vehicles or other equipment.

The decommissioning of the Benjamin Franklin-class submarines spanned a decade from 1992 to 2002, prompted by strategic arms limitation treaties, the induction of Ohio class submarines, their own aging, and the dissolution of the Soviet Union. The USS Kamehameha was the last to be decommissioned on April 2, 2002. Several components of decommissioned vessels, including the sail sections, have been preserved at various locations like the Naval Submarine Base King's Bay, Georgia, the National Museum of Nuclear Science & History in New Mexico, the Mare Island in California, and the Patriot's Point Maritime Museum in Charleston, South Carolina.

Technical specifications