The Ohio-class ballistic-missile submarine [3] (SSBN) was built to destroy cities and military installations in the event of a nuclear war—or more precisely, to deter adversaries from ever starting one. However, following the end of the Cold War, the U.S. Navy determined that it didn’t need all eighteen of its underwater horsemen of the apocalypse for the nuclear deterrence mission.
The Navy first intended to scrap the four oldest of the massive submarines, but instead opted to overhaul and convert them to launch Tomahawk land-attack cruise missiles (TLAM) at a cost of $700–900 million each. These vessels were redesignated Ohio-class guided-missile submarines (SSGN) and intended to deliver conventional attacks on targets on land. The Ohio and Florida began the nuclear refueling, overhaul and armament upgrade in 2003 and were back in service by 2006, while the Michigan and Florida followed in 2008.
The Ohio-class SSGN bristles with more conventional firepower than any comparable vessel because its twenty-four missile tubes (eighty-eight-inch diameter) were originally designed to carry enormous Trident ballistic missiles. Twenty-two of them were refitted with Tomahawk launch canisters with seven missiles each, for a total of 154 Tomahawks missiles, all of which can be ripple-fired from underwater in the space of six minutes. This is likely to be a heavier cruise-missile armament than an entire surface task force.
The Tomahawks, which each cost over $1.5 million, are capable of delivering a thousand-pound warhead to land targets as far as a thousand miles away, guided via GPS. This, incidentally, means that Ohio SSGNs are carting well over $200 million in missiles when fully loaded.