Diesel submarines becoming a main irritant to U.S. Navy.

Following several years of relative inaction, the U.S. Navy is charging ahead with plans to neutralize what it sees as the growing menace of enemy diesel-electric submarines.

Diesel-electric boats, although relatively low-tech are emerging as a decided threat to military assets around the world and civilian targets the United States, officials said. Unlike large nuclear-powered attack submarines, diesel boats can operate covertly in coastal areas or in the vicinity of U.S. floating bases, possibly blocking U.S. access to combat zones and making U.S. vessels vulnerable to torpedo attacks.

Because they are much less costly to produce than nuclear submarines, easily available on the world arms market and hard to detect, diesel boats now are viewed as classic "asymmetric" threats that could wreak havoc on a technically superior U.S. naval force.

Adm. Vernon Clark, chief of naval operations, is expected to approve this fall an "anti-submarine warfare master plan" and a "concept of operations" on how to counter diesel-electric submarines.

Clark also set up new organizations dedicated to anti-submarine warfare. A Washington, D.C.-based task force stood up last year was directed to "identify new technologies and concepts of operations to fundamentally change anti-submarine warfare," said Capt. David Yoshihara, who heads the organization.

In San Diego, the Navy created a Fleet Anti-Submarine Warfare Command--led by Rear Adm. John J. Waickwicz--that is focused on sharpening commanders' anti-submarine war-fighting skills. Meanwhile, a new program office at the Naval Sea Systems Command is responsible for coordinating all anti-submarine warfare research, development and procurement across the Navy.

After the cold war, the Navy neglected anti-submarine warfare, on the assumption that Soviet subs no longer were a menace. But the proliferation of diesel-electric submarines around the world prompted Navy leaders to rethink their priorities, noted Capt. Paul Rosbolt, who oversees anti-submarine warfare programs at the Naval Sea Systems Command.

"We didn't pay attention to anti-submarine warfare for a while," said Rosbolt in a recent interview. "We allowed equipment to fall behind. We didn't train as much as when there was a Soviet Navy to practice against."

Fighting enemy diesel submarines requires new skills and sensor technologies that the U.S. Navy has not yet perfected, said Rosbolt. While Soviet nuclear submarines sail in deep oceans, the quieter diesel boats generally operate in shallow coastal waters.

Anti-submarine warfare is a complex discipline that cannot be learned overnight, he noted. It requires a profound understanding of submarine tactics and the ability to "ready the enemy's mind," much like a chess game, explained Rosbolt.

The 1981 film "Das Boot," which immortalized the claustrophobic world of a World War II German U-boat--with all its boredom, filth and sheer terror--is mandatory viewing for all anti-submarine warfare officers, Rosbolt noted.

Diesel submarines come in many shapes and forms. The U.S. Navy, which no longer operates diesels, does not necessarily worry about the old Soviet-era boats that have been sitting by the pier for 15 years without any maintenance or crew training.

"Those are relatively easy to deal with," said Rosbolt. Of most concern are the newer diesel-electric boats made by several European nations, most of whom are U.S. allies. Those submarines are more technologically advanced, quieter and have a longer battery life, which means they can stay submerged and undetected for extended periods of time.

John Young, assistant secretary of the Navy for research, development and acquisition, said at a news conference last month that 40 countries today operate more than 400 submarines, 75 percent of which are considered "modern" boars.

"Their advantage is stealth," said Waickwicz, head of the Fleet Anti-Submarine Warfare Command. "They can hover, sit on the bottom for long periods of time. They can sit as an ambush, or they can be out working in wolf-packs."

By comparison, the U-boats of World War II had limited battery endurance and had to snorkel frequently. "Now, they can lay in wait for a long time in stealth mode," said Waickwicz. Most submarines carry cruise missiles, torpedoes and mines--the same armaments found aboard nuclear attack submarines.

The Navy's anti-submarine warfare master plan, to be completed in September, will outline current programs and technologies deemed relevant for ASW operations. It will identify "gaps" in existing capabilities that need to be addressed in the future. The last time the Navy updated its anti-submarine warfare master plan was 1991.

To pay for new ASW capabilities, the Navy will reallocate funds from existing programs, said Rosbolt. "The CNO wants us to do this without breaking the bank," he said, although it is not yet clear whether some of the technologies now envisioned for future ASW operations are affordable within the current budget.

To capture the state of the technology, the Navy is reaching out to the private sector, he noted. In recent months, several "broad agency announcements" were published, seeking contractor proposals for how to develop and deploy miniature sensors at sea and how to defend submarines from torpedo attacks, for example.

Following a venture capitalist approach, the Navy will ask companies to validate their technologies in various exercises and experiments during the next two years. Those that show the most promise will get funding, said Rosbolt.

The complexity of anti-submarine warfare makes it impossible to rely on any one single technology or weapon system, be added. "There is no silver bullet in ASW.... We can't build a single system that is going to find every submarine in every kind of environment. It will take a mix of systems."

Another piece of the Navy's strategy is an information campaign designed to put potential enemies on notice that the United States is well equipped to defeat diesel subs, said Yoshihara, who runs the ASW task force in Washington.

"We want countries to know that our ASW capability is so good that it would be a bad investment on their end.... We want to send a message that we are investing in ASW."

One significant obstacle for anti-submarine operations is the amount of time needed to gain enough intelligence about the enemy. The Pentagon strategy instituted recently by the Bush administration calls for gaining access of an area of operations within 10 days.

That is a "demanding timeline" for ASW,, said Yoshihara. "ASW takes a long time." It takes weeks sometimes to gather intelligence and analyze it. That gives enemy diesel subs more than enough time to figure out they have been detected. "We have a tendency to lose them, because ASW is a difficult environment," Yoshihara said.

The answer to shortening the response time, the Navy believes, is to deploy "distributed sensor networks" across large areas of the ocean. Up to hundreds of small sonobuoy sensors would be launched from ships or aircraft, and left unattended for several days or weeks. If the sensors detected a suspected enemy submarine, a ship commander nearby would be alerted.

An effective anti-submarine strategy will need to draw from every element of naval warfare: air, undersea and surface, said Waickwicz. "We try to integrate all three across the spectrum of ASW. It is quite a challenge to bring all the communities together," he told National Defense.

The Navy's attack submarines are primary ASW platforms, as are the P-3 Orion patrol aircraft, equipped with anti-submarine missiles. The Navy announced last month it will spend up to $44 billion on a new fleet of maritime surveillance jets that will replace the P-3.

Aircraft such as the P-3 and their future replacement are "clearly the best platforms for doing wide-area search and doing the localization required to track the diesel submarine," said Tom Laux, program executive officer for air anti-submarine warfare. "Today's modern diesel is a very, very challenging threat," he told reporters.

Another multibillion-dollar program conceived in part for anti-submarine warfare missions is the Littoral Combat Ship.

The LCS will have several ASW roles, said Rear Adm. William E. Landay, program executive officer for littoral and mine warfare. "The first is to be able to provide a persistent large area detection capability." Helicopters or inflatable boats deployed from the LCS would be able to launch sonobuoys to help detect and locate submarines, Landay said. To destroy submarines, the LCS would deploy an MH-60 helicopter outfitted with missiles.

Besides developing new technology, the Navy will need to revamp training programs and promote the need for increased ASW proficiency in the fleet, said Yoshihara. Junior officers, particularly, "want to understand where we are headed with ASW," he said. The Navy's strategy will require a cultural adjustment, such as operating as part of a network, rather than in isolated ships. "It's "eye opening' to be involved in a group," he said. "We don't have an appreciation for that. We focus on 'my sonar' or 'your sonar.'"

A cornerstone of the ASW training program is a series of multinational exercises, explained Waickwicz. Those drills can be particularly useful, because many allied nations operate diesel submarines, and provide a realistic "red force" for the United States to match up against. Bilateral exercises will take place later this year with Japan, Chile and Canada.

For a recent exercise in Iceland involving the United States, Poland and Norway, the Polish Navy provided Kilo diesel submarines it had received from Russia.

One drawback, however, is the inability for all exercise participants to share data in real time and exchange "lessons learned" immediately after the event, noted Waickwicz.

In recent months, the U.S. Pacific Fleet and the Naval Undersea Warfare Command have been working on a so-called "ASW tactical assessment tool," an online database that stores information from all Navy ASW exercises and helps assess the fleet performance.

"It doesn't do any good to do an analysis six months after the exercise," said Waickwicz. "People no longer remember what it was like or what they were doing."

As more battle group commanders take part in ASW exercises, they will gain appreciation for these skills, he said. "If we can bring exercises that have merit, we can get targets to practice the science and the art of ASW, people will want to do it.

"If you do ASW once every four months or six months, you get very frustrated, because you cannot get the proficiency, the fidelity in training. You lose it. If you do it on a continuing basis, at sea or ashore in synthetic simulation, ASW is very rewarding as a warfare specialty."