Ohio-Class Submarine

The Ohio class is a class of American nuclear-powered submarines, with the lead ship USS Ohio commissioned in 1981, built in two variants: fourteen ballistic-missile submarines that carry the Trident II submarine-launched nuclear missile and form the sea-based leg of the American nuclear triad, and four earlier boats converted into guided-missile submarines carrying large numbers of conventional Tomahawk cruise missiles along with facilities for special-operations forces. Each ballistic-missile Ohio-class submarine can remain submerged and undetected for extended patrols lasting months at a time, a survivability advantage considered central to nuclear deterrence, since an adversary attempting a first strike cannot reliably locate and destroy a submarine hidden somewhere in the open ocean the way land-based missile silos or bomber bases can potentially be targeted. The class is scheduled to be gradually replaced beginning in the 2030s by the new Columbia-class ballistic missile submarines, but Ohio-class boats are expected to remain the backbone of the American sea-based nuclear deterrent well into that transition.