Project 1840 is the name of a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nation ...

diesel-electric submarine design of which only one vessel was built. The design is known in the west by its NATO reporting name ''Lima''. The submarine, which was assigned hull number БС-555 (БС, ''большая специальная'' or ''bolshaya spetsialnaya'', meaning ''large special''), was completed in 1979, and used by the Black Sea Fleet. It was decommissioned and laid up in 1994. The exact purpose of this boat has remained unclear to western observers. It is suspected that it had an auxiliary role and was used for trying out new technologies, research, or special mission support. The vessel was assumed to be unarmed.

External links

Federation of American Scientists: Lima
{{DEFAULTSORT:Lima-class submarine Russian and Soviet navy submarine classes Auxiliary ships of the Soviet Navy