American submarine NR-1

Deep Submergence Vessel NR-1 was a unique United States Navy (USN) nuclear-powered ocean engineering and research submarine, built by the Electric Boat Division of General Dynamics at Groton, Connecticut. NR-1 was launched on 25 January 1969, completed initial sea trials 19 August 1969, and was home-ported at Naval Submarine Base New London. NR-1 was the smallest nuclear submarine ever put into operation. The vessel was casually known as "Nerwin" and was never officially named or commissioned. The U.S. Navy is allocated a specific number of warships by the U.S. Congress, but Admiral Hyman Rickover avoided using one of those allocations for the construction of NR-1 in order to circumvent the oversight that a warship receives from various bureaus.