Beyond the Gates

It's no secret that the Navy has a research facility in Bayview, Idaho. Some of the equipment and submarines are in plain view when you drive into town. Although what goes on behind the gated area is mostly classified, the Navy has been open about some of the work it does in the name of our country’s defense.

Navy’s Mission in Bayview: Acoustic Stealth Technology

The naval facility began in 1942 as part of the Farragut Naval Training Station. After WWII, the training station closed in 1947, and the Navy turned much of the property over to the state but held on to 22 acres. There are still boathouses and a pier leftover from that era. The research and testing began immediately.

“We’re proud stewards of the lake,” Alan Griffitts, Detachment Director, said. “The community gives us great support.” The Navy even protects an area where the Kokanee salmon spawn at the facility.

What Lake Pend Oreille offers is an environment perfect for collecting data on acoustic stealth technology. Navy researchers collect data on how “quiet” the submarines’ design and equipment are. The quieter the submarines are, the less likely they may be detected by enemy sonar systems. In addition, the serenity of the lake offers an optimal environment for obtaining extremely accurate data because there is little extraneous noise.

The lake bottom is also optimal for acoustic testing: Its mountainous shores are clear of debris and sea life. It’s the deepest lake in Idaho, measuring 1150 ft. deep, and the fifth deepest in the country. Much of the testing takes place at night after recreational boaters have gone home.

Acoustic Research and Testing

The facility at Bayview is the Acoustic Research Detachment (ARD) managed by the Naval Surface Warfare Center (NSWC) Carderock Division in Maryland, which is a division of the Naval Sea Systems Command (NAVSEA). About one hundred people are employed at the facility - half are employed by the Department of Navy and the others are contracted employees. They use large scale submarine models to test ship design and its acoustic impact. In other words, a submarine’s ability to be quiet.

“Our main mission is to make quiet submarines, reducing their potential of detection from enemy sonar to make them more effective in safely and effectively accomplishing their mission. The ARD is instrumental in the design of the last four classes of submarines and future classes too,” Griffitts said. “Building an effective platform is how we fulfill that mission.”

The models utilized at the ARD are one-third to one-fifth of the full ship’s size. The research done at Bayview includes evaluation of submarine design, environmental quality systems, hull shape, propulsor noise reduction, structure materials, acoustic signature, machinery systems and vulnerability and survivability systems as listed in Navy literature about the NSWC Carderock Division.

“They allow us to put a high fidelity systems on models, capture data and assess what it would be like on a full-scale model,” Griffitts said.

They don’t test sonar systems or weapons, he noted. The focus is on design and on making submarines quiet enough to bypass detection and also withstand the pressure of deep waters.

“Pressure is a submarine’s biggest enemy,” he said.

Researchers perform a variety of tests to measure pressure and noise from submarine movement. A yellow platform visible on the lake is a static test facility that’s over 600 ft. of water. Researchers lower various devices using cranes and winches for acoustic testing.

Another type of experiment tests how quiet the equipment is inside a submarine’s hull. It’s called an Intermediate Scale Measurement System (ISMS). The testing area is a large array of underwater hydrophones that researchers lower so they test the technology inside a submarine.

“Hydrophones convert pressure waves into an electrical signal. We can then measure that electric signal and make a determination of the pressure wave that’s passed it,” Griffitts said. “We use them to measure how much noise occurs. We want the machines and submarines to be quiet. These sensors measure how quiet they are.”

Model Submarines

One of the primary models used is the Large Scale Vehicle (LSV-2), named “Cutthroat” by Athol Elementary students back in 2000. It’s the world’s largest autonomous underwater vehicle. It sits on a platform that’s lowered into the water, towed, then submerged when its ballast tanks are filled with water.

“We need to make sure that our models are quieter than what we measure. LSV-2 is the Navy’s quietest sub,” Griffitts said.

LSV-2, a scaled Virginia class submarine model, has 3,000 shaft hp and runs off batteries. Being autonomous, it also takes recovery action if something doesn’t work properly. There are transducers at the bottom of the lake, which act like underwater speakers and record data. If anything needs modification, the structure can be altered.

“That’s what makes a large scale model so effective. To be able to affordably modify and test those modifications,” Griffitts said. “The Navy’s made a significant investment, with testing accomplished at the ARD leading to a significant reduction of total submarine costs by up to $500 million each.”

Another type of submarine tested is a buoyant vehicle called, the Dolly Varden. Researchers tow the vehicle under and release it to the surface to measure its noise.

“We grab it by the tail, pull it to the bottom of the lake and release it. As it’s flying through the water, we can measure how much noise it makes. It’s a quiet, inexpensive platform,” he said.

A third model is the Sea Jet, which is a manned surface ship demonstrator. It’s a diesel electric surface ship utilized to test surface ship propulsion systems. It has the capability to operate on battery power and makes very little engine noise. It is also used to take acoustic measurements.

Finally, there is the LSV-1, the Kokanee (a Seawolf class ship), which is LSV-2’s predecessor. It was tested at the facility from 1987 to 2005 and decommissioned when LSV-2 was introduced as the more modern platform.

While the research done at Bayview is in the name of U.S. defense, more directly, it is to protect the sailors on those ships from an enemy.

In a Navy YouTube video, Griffitts said, “(We) help provide the Navy the quietest submarine platform they can afford so that sailors can go do their job safely and effectively and return safe to their families.”

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