Russian Borei-class submarine. Via Ship Model Forum

Russia’s Future Subs Could Be Smaller, Quieter, Cheaper—And Totally Unsuitable

Non-nuclear undersea boats would be incompatible with Arctic ops

In coming decades, the Russian navy could replace its nuclear-powered submarines with battery-powered models that are smaller, harder to detect and cheaper to build.

But the non-nuclear approach to future subs is risky, particularly for under-ice Arctic operations. It’s not for no reason that the world’s leading undersea power, the United States, is committed to an all-nuke sub fleet.

“I believe future submarines will be smaller, because of the use of more advanced technologies as well as the pursuit of more cost-effective production,” Sergei Sukhanov, senior naval architect at the Rubin submarine design bureau, told RIA Novosti.

“The fifth-generation boat will also be less ‘visible’ compared with existing submarines,” Sukhanov added. “They could also feature a new power plant, including fully electric.”

But building more, smaller conventional subs would represent a major departure for the Russian navy. While Russia, and the Soviet Union before it, has long maintained a mix of nuclear and diesel-electric subs, the nuke models have always been the flagships of the fleet.

Tougher, more heavily armed and longer-ranged owing to their larger size and atomic powerplants, nuclear undersea vessels can do things that diesel-electric subs generally can’t: cross an ocean underwater and at high speed and travel for weeks at a time under the Arctic icecap.

True, conventional subs are cheaper to build than nuclear models because they don’t need high-tech reactors and can be smaller as a result. A modern diesel-electric sub sets a government back half a billion dollars or so, a fifth the cost of a typical nuclear vessel.

Diesel-electrics can be quieter than nukes under some conditions, mostly because they don’t need to noisily circulate coolant through a reactor. But the diesel-electric subs are much slower and, because their batteries drain, can spend less time under the waves or ice before needing to surface.

And the conventional boats’ advantages might not matter much for a government determined to maintain a military presence in the Arctic circle.

The USS Annapolis at the North Pole in 2009. Navy photo

Chill factor

It was the advent of nuclear propulsion that allowed the U.S. Navy to pioneer sustained Arctic submarine patrols, starting with USS Nautilus’ cross-polar voyage in 1958. Since then the Navy has routinely, and quietly, sent attack submarines on voyages under the ice totaling thousands of miles—most recently the secretive USS Seawolf, which crossed the North Pole this fall without many people noticing.

The Russians were quick to follow the Americans to the Arctic. At the height of the Cold War, Moscow’s nuclear submarines concentrated in polar waters, where the uniquely complex acoustics make detection by sonar very difficult. “Only in the Arctic Ocean was the Soviet navy reasonably sure of being able to keep its ballistic missile submarines secure,” Nicholas Tracy wrote in his book Two-Edged Sword: The Navy as an Instrument of Canadian Foreign Policy.

The desire to continue patrolling the Arctic is one reason that U.S. Navy leaders steadfastly ignore advocates calling for a new generation of American diesel-electric subs. The Pentagon recently picked the design for its next attack submarine—a slightly enlarged update of today’s Virginia class, which is nuclear-powered. The first Virginia-class vessel to go to the Arctic was the USS New Hampshire, in 2011.

All that said, Sukhanov’s prediction of a non-nuclear future fleet is not without some basis in reality. So-called “Air Independent Propulsion” technologies make it possible for conventional submarines to go longer than previous diesel-electric boats without gulping fresh air for their engines.

The world’s best non-nuclear subs, the German Type 214 and the Japanese Soryu class, both can travel thousands of miles at four to seven knots without surfacing. The Norwegian navy, which patrols the Arctic’s fringes, is planning to buy similar cutting-edge non-nuclear submarines.

Still, for all the advances in conventional undersea propulsion, atomic boats remain much better by certain metrics. They can stay underwater at top speeds for months.

And they’re fast. Seawolf set what might be an operational undersea speed record in late 2001 as she quickly repositioned to support counter-terrorism operations. “We went halfway across the Atlantic in about 48 hours,” said Cmdr. Butch Howard, skipper at the time.

For the record, that’s 1,500 miles or so in just two days, for a sustained speed of no less than 31 knots. A feat no conventional boat can match, no matter how modern.

Moscow seems to appreciate nuke boats’ advantages, regardless of cost and despite what Sukhanov said. Russia’s Arctic ops are critical to “implementation of the country’s foreign policy priorities,” a Kremlin official said in 2010. He stressed that nuclear submarines would continue patrolling northern waters.

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