Navy Has No Silver Bullets to Defeat Mini-Submarines, Underwater Mines

For the U.S. Navy, it would be an apocalyptic scenario: A critical chokepoint of global trade and oil tankers, the Strait of Hormuz, shut down by the suspected, or real, presence of sea mines. The Navy regards the protection of the world’s commerce lifelines as a raison d’etre, and has spent decades developing mine detection and mine sweeping technology to deal with precisely such circumstances.
Iran has in the past put the world on guard that it would close the Persian Gulf to shipping if it were attacked. The impact would be huge. Americans mostly would feel it at the gas pump, with oil prices soaring out of control.
Fears of Iran burying sea mines — often called the improvised explosive devices of naval warfare — in strait waters have fueled Navy’s efforts to improve its countermeasures. But today’s anti-mine systems may not be enough to defeat these stealthy weapons. Current technologies were optimized for operations in open oceans, and may not necessarily work in the Strait of Hormuz’ murkier, more cluttered, relatively shallow waters, analysts contend.
Navy officials will not publicly discuss the precise capabilities of current anti-mine systems to keep the strait open despite such threats. The Navy for years has been concerned about “asymmetric” weapons that deny U.S. ships access to any area of the world, said Vice Adm. David J. "Jack" Dorsett, deputy chief of naval operations for information dominance, and a career intelligence officer. Today’s surface ships have advanced systems to defend themselves from enemy missiles or incoming small boats, but concealed threats such as mines or mini-submarines are tougher to counter.
Strategists have speculated that if Iran’s regime were to ever carry out such actions, that they would deploy mines via so-calledmidget submarines that are operated by a crew of one or two sailors. They are battery powered and not likely detectable by U.S. vessels. These submarines are what worries the Navy the most, Dorsett said. “Over the past year, especially since the sinking of the [South Korean Navy corvette] Cheonan, we have become increasingly concerned about the numbers of small mini-submarines that are indigenously produced in Iran,” he said Jan. 5 during a meeting with reporters in Washington, D.C.
The ability to find these tiny submarines is an issue “we are spending some time and energy on,” Dorsett said.
South Korean officials claim that a North Korean Yono-class midget submarine fired the torpedo that sank the Cheonan. The same boats could be used to lay large numbers of mines across the Strait of Hormuz, experts assert. Yono boats are believed to be virtually undetectable once they are at sea.
Programs are now under way in the U.S. Navy to develop advanced detectors. They would be mounted on undersea unmanned vehicles, which would be launched from surface patrol boats.
Unleashing a swarm of sensors into the water, however, is only half the battle. An even bigger hurdle is the ability to interpret the data that sensors collect and be able to quickly discriminate real mines or mini-submarines from boulders or schools of fish.
Dorsett noted that managing data and making sense of the information is one of the Navy’s “largest challenges.” Speaking in broad terms about intelligence collection and analysis in current war zones, he said more automation, in addition to well-trained analysts, is needed in order to process growing mounds of data.
Having self-reliant, or autonomous, UUVs and automated intelligence analysis tools is essential in mine-detection operations because there are so many potential false alarms. UUVs use sonar as their primary means of navigation. Artificial intelligence tools would be required to interpret the sonar returns and determine if there is an obstacle the UUV needs to avoid. Similar technology is needed to recognize possible mines.
In littoral environments such as the Strait of Hormuz there are many obstacles, including rocks, reefs and abandoned fishing nets that UUVs would have to steer around.
The Navy is still struggling to bring these technologies to fruition. One snag that is slowing things down is that current UUVs can’t stay underwater long enough to be effective in shallow-water mine or submarine hunting.
“While I want to transition the rather mature [unmanned underwater vehicle] technologies to the fleet, we continue to wrestle with UUV power and energy” issues,Chief of Naval Operations Adm. Gary Roughead said in August.
The desire is to have UUVs that can swim for three to four weeks at a time. The Navy during the next five years is investing 50 percent of its research and development funds on energy technology for unmanned systems, Roughead said.
Once the power and endurance obstacles are overcome, the next hurdle is to develop better information networks to connect UUVs, said Roughead. Because the underwater vehicles will cover large areas of the ocean, they will need to operate in an integrated network, he said. The Navy last year canceled the development of one of its most ambitious UUV programs, known as mission reconfigurable UUV. “We were putting a lot of money into it and it wasn’t going anywhere,” Roughead said.

Topics: Undersea Warfare