The Navy operates only 11 nuclear-powered surface ships—the aircraft carriers (CVNs) that are the centerpiece of the its power-projection capability. Although nuclear propulsion has been around for more than 60 years, it remains a special technology whose operation and maintenance require individuals to undergo significant initial training, continual refresher training, and regular examinations throughout their careers. Nuclear-trained limited duty officers (LDOs) and surface warfare officers with a nuclear power sub-specialty (SWO[N]s) provide the carriers their power plant division officers, principal assistants, and department heads. SWO(N) officers serve alternating tours as bridge officers on conventional surface ships and as engineers on aircraft carriers.
