Toning Up the Nuclear Triad

In the 40 years since the Enola Gay, a B-29 long-range medium bomber, dropped its atom bomb over Hiroshima, America's nuclear-weapons systems have evolved into what has been known for the past 25 years as the Triad. The name comes from the fact that U.S. strategic nuclear weapons are based in the water, on land and in the air. Defense strategists agree almost universally that all three legs of the Triad are essential because each by itself has weaknesses that are offset only by the strengths of the other two. Land-based intercontinental ballistic missiles (ICBMs), for example, are the most accurate and powerful strategic weapons in the nation's arsenal, but the fixed underground silos in which they are stored also make them the most vulnerable. Airborne bombers, which can be recalled from attack up to the moment their nuclear payload is fired, provide a President with the most flexible strategic weapon currently available, but also the slowest. Submarine-based missiles are virtually undetectable by the Soviets, but at least until recently, they were considered less accurate than land-based or airborne missiles.

As part of its overall military modernization, the Reagan Administration has ordered or overseen major improvements in all three of the Triad's legs. To assess the changing nature of the nation's strategic defense machine, TIME Pentagon Correspondent Bruce van Voorst sampled day-to-day operations in each of the Triad's components. He dived with the Trident submarine Henry M. Jackson off the Bahamas as the vessel made final preparations to join the Pacific Fleet, strapped himself into the cramped confines of a B-52 on a simulated bombing strike out of South Dakota's Ellsworth Air Force Base and inspected a Minuteman training launch capsule, also in South Dakota. Van Voorst's report:

The nuclear-powered Jackson is the fifth of 20 Trident submarines planned for sea duty by the 1990s. With a length of 560 ft. and a weight of 18,700 tons, it is as big as a World War II cruiser, yet it glides under the surface at speeds of more than 25 knots (comparable land speed: 28.7 m.p.h.) and is capable of operating at depths considerably greater than the 600 ft. to which Navy sources admit. Tridents carry the single most devastating element of the Triad. Stowed inside tubes that cut like shafts through the Jackson's four decks are 24 Trident I C-4 missiles, each carrying up to ten nuclear warheads, every one of them with a yield of 100 kilotons and capable of destroying a midsize Soviet city. With a range of more than 4,000 nautical miles, the missiles can deliver their deadly packages of firepower within 1,000 ft. of target center.

The Jackson's mission will be to prowl the Pacific depths on cruises averaging 70 days, always remaining hidden and within missile range of its targets. Says Captain Michael Farmer, 45, a lanky six-footer with an air of quiet self-confidence: "Our job is to go to sea and disappear. Our total invulnerability to Soviet strikes then becomes a factor of deterrence."