Ohio Class SSBN on Deck. Since its inception in 1960, strategic deterrence has been the sole mission of the fleet ballistic missile submarine (SSBN), which provides the nation's most survivable and enduring nuclear strike capability. The eighteen submarines of the Ohio class replaced aging fleet ballistic missile submarines built in the 1960s and are far more capable. Carrying twenty-four Trident missiles each, the Ohios carry fifty percent of all US strategic deterrent nuclear warheads and provide the sea-based 'leg' of the US strategic deterrent triad. An unprecedented bow-to-stern look at this critical US weapon system with more than 200 color and b/w photos, line drawings and 8 color profiles; 80 pages.