USS Narwhal (SSN-671)

USS Narwhal (SSN-671) was a one-off nuclear attack submarine of the United States Navy, built to project SCB 245 as a class of her own. The Electric Boat Division of General Dynamics laid her down on 17 January 1966 at Groton, Connecticut; she was launched on 9 September 1967 and commissioned on 12 July 1969. Forward of the reactor compartment she resembled the Sturgeon-class boats, but her natural circulation S5G reactor and large direct-drive turbine, which turned at only 300 revolutions per minute, made her one of the quietest submarines of her era. The S5G design was later scaled up into the S8G reactor of the Ohio-class submarines. She was decommissioned on 1 July 1999 and dismantled under the Navy recycling program by October 2020.