Ethan Allen-class submarine
 The Ethan Allen class of fleet ballistic missile submarine was an evolutionary development from the George Washington class. The Ethan Allen together with the George Washington Lafayette James Madison and Benjamin Franklin classes comprise the 41 for Freedom.Rather than being designed as Skipjack class attack submarines with a missile compartment added the Ethan Allens were designed from scratch as Fleet Balistic Missile (FBM) submarines carrying the Polaris A-2 missile.