U.S. Navy's Worst Nightmare: Submarines May No Longer Be Stealthy

New technology might just dampen the awesome capabilities of one of America's most lethal weapons. What can the Navy do about it?

S’pose Bryan Clark has it right. The Center for Strategic and Budgetary Assessments (CSBA) analyst and retired U.S. Navy commander postulates that a technological revolution is about to overtake undersea warfare, rendering the wine-dark sea transparent to hostile antisubmarine (ASW) forces for the first time. This would be a bad thing from the standpoint of U.S. naval mastery. It would place in jeopardy America’s capacity to execute an ambitious foreign policy in distant waters, preside over the liberal maritime order, or accomplish all manner of worthy goals.

Such matters were much on my mind while careening down I-95 to the submarine base at Groton, Connecticut last week, there to commemorate the anniversary of the Battle of Midway. The event took place on the pier where USS Nautilus—the United States’ and the world’s first atomic submarine—lies berthed as a nautical museum. Earlier this year the silent service marked the sixtieth anniversary since the day when Nautilus’s skipper first radioed home: “Underway on nuclear power.”

That signal heralded a new age in undersea combat—the age our doughty CSBA analyst contends is giving way to another new age. The advent of naval nuclear propulsion let these newfangled craft remain underwater for long stretches of time. It spared them the need for regular refueling. Machinery needed little sustenance apart from routine upkeep and overhauls. Stores such as food and other necessities for the crew became the chief limiting factors on nuclear boats’ voyages. For the first time submarines became true denizens of the deep, as opposed to surface ships able to submerge temporarily.

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Nuclear power, moreover, shunted the competition between subs and sub hunters—what Clark calls the “hider-finder” competition—into the acoustic realm. No longer could anti-submarine forces count on finding enemy boats cruising on the surface, lurking just below the surface with a periscope or snorkel peeking above, or using radio or radar with their telltale electromagnetic emissions. They could hide more or less indefinitely.

Sound, then, is the chief limiting factor on stealth. Sub designers and crews go to elaborate lengths to keep machinery and other sources of noise quieter than an opponent’s passive sonar—sophisticated listening devices, and any navy’s ASW tool of choice—can detect. A quiet boat is an elusive boat. It can prowl the depths, prey on fellow subs or surface craft, or project power onto hostile shores. But, writes Clark, Big Data coupled with non-acoustic detection, tracking, and fire-control technology may soon expose American boats to the prying eyes of hostile forces.

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For instance, ASW hunters could look for minute disturbances a submarine makes to its tactical surroundings. The most hydrodynamic hull makes a wake as it travels through water. Engineering plants discharge heat. Undersea craft may interfere with sea life as they pass. Finding such traces of an American sub’s presence—and parleying that information into actionable tracking and targeting data—would nullify its core advantage in whole or in part—namely its ability to vanish beneath the waves. A visible boat is a vulnerable boat. The competition between hiders and finders could swing decisively in favor of super-empowered sub finders after six decades of supremacy for the hiders.

That leaves the silent service—where, precisely? Struggling to stay abreast of the times, one suspects. That’s how beneficiaries of a congenial status quo commonly respond when change shakes their world. Paradigm shifts are agony for entrenched cultures. Stakeholders in the ancien regime resist believing that shifting circumstances have rendered old ways partly or wholly moot. Oftentimes they fight against unorthodox methods that are better fitted to the times. Progress is fitful and uncertain. Strategic innovation tends to lag behind events.

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