With the advent of atomic power, the submarine underwent major changes in propulsion and striking power. In the nuclear-powered submarine an atomic reactor generates heat that drives a high-speed turbine engine. The first nuclear-powered submarine was the U.S. Nautilus, completed in 1954. Such submarines, with underwater speeds of above 30 knots, can remain submerged for almost unlimited periods of time and have circumnavigated the globe without surfacing. In 1960 the U.S.S. George Washington was the first submarine to fire a missile from a submerged position; the same year the U.S.S. Triton became the first vessel to circumnavigate the world while submerged. The development of nuclear-powered submarines capable of launching missiles without surfacing has greatly expanded the role of the submarine; its mission is no longer restricted to the destruction of ships (including other submarines), but it now also has the role of firing guided missiles (nuclear or conventional) at land targets deep inside an enemy's borders, as U.S. submarines did during the Persian Gulf War. In the 1990s South Anerican drug cartels began using diesel-powered submarinelike vessels to smuggle illegal drugs. Now built largely of fiberglass, these vessels either travel at the surface, with most of the vessel, except for a conning tower, submerged or, in some cases, are capable of traveling fully submerged on batteries, coming to the surface at night to recharge using diesel engines.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.