Undersea Warfare The Official Magazine of the U.S. Submarine Force. Winter 2004 U.S. Submarines... Because Stealth Matters Cover for Winter 2004
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From Humble Origins
China’s Submarine Force Comes of Age

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The Naval Submarine Medical Research Laboratory:
A Little-Known Lab Makes A Big Impact!
Navy Captain Victoria Cassano, serving as a subject for a research dive in the Bahamas, looks at the sound attenuation provided by a standard 7 mm wetsuit hood.

The new emphasis on world-wide asymmetric threats, with submarines operating more frequently within the littoral, has
created the demand for new ways to address longstanding health and safety issues in today’s Submarine Force. Leading the way in examining these concerns is a little known research facility located at SUBASE New London – the Naval Submarine Medical Research Laboratory (NSMRL).

Consider the following scenario: With their nuclear submarine disabled by a collision at sea and one compartment isolated, the boat’s crew awaits rescue in shallow littoral waters off a hostile country.Unable either to surface or to operate many key systems, the crew needs to make time-critical decisions that will affect both their endurance and survival.

Throughout the submarine, the atmosphere is continually being “scrubbed” of carbon dioxide by hanging “curtains” containing enhanced lithium hydroxide. Meanwhile, the senior person present in each compartment is using a conventional PDA to calculate the time remaining before escape becomes mandatory, with input data from new gas analyzers recently installed onboard. Eventually, the decision is made that escaping from the submarine is unavoidable. Fortunately, this crew will wear the new Submarine Escape Immersion Equipment (SEIE) – full-body survival suits with built-in life rafts – and their chance of making it to the surface and surviving there are better than ever.

All of these items, from the analytical software in the PDA to the new SEIE suits have been developed or evaluated for use by the researchers at NSMRL.

For over 75 years, NSMRL has been the Department of Defense (DOD) Center
for Undersea Biomedical Research. Established in the closing days of World War II to conduct mission-critical studies in night vision, sonar sound discrimination, and personnel selection for the Submarine Service, the laboratory’s efforts in submarine, diving, and surface biomedical research support its mission to protect the health and enhance the performance of today’s warfighters.

Over the years, NSMRL has sponsored an impressive array of high-impact innovations. For example, the laboratory was responsible for the SEALAB underwater habitat, development of the International Orange color for visibility, and the Farnsworth Lantern Color Vision test.
In addition, NSMRL scientists, have used the hyperbaric chambers at their facility
on SUBASE New London to develop many of the saturation and diving decompression tables in use today. NSMRL also researched many current sonar displays and developed a psychological screening test
for prospective submariners.

NSMRL has been named
the bio-effects lead for
DOD’s development of
diver deterrence systems.

Today, NSMRL continues to address critical issues for the undersea community, with emphasis on submarine survival and rescue, submarine medicine, diver bio-effects, hearing conservation, and situational awareness. This in-house research is pursued in close association with Submarine Force and fleet elements, such as the newly established Submarine Learning Center, Submarine Development Squadrons 5 and 12, and the Naval Submarine School.

All of the laboratory’s efforts are focused on the warfighter. For example, Dr. Ed Cudahy leads a major on-going program studying the bio-effects of underwater sound on the human diver. One of his projects involves the measurement of noise made by underwater tools at working dive sites. His team of scientists and divers descended into history recently when they collected in situ data as part of a preservation project for the USS Arizona Memorial in Pearl Harbor, Hawaii. The NSMRL team collaborated with Mobile Diving and Salvage Unit (MDSU) 1 and the National Park Service, making underwater noise measurements of a new hydraulic tool designed to remove samples of the battleship’s hull for metallurgical analysis. The research team had to collect underwater noise levels as part of NSMRL’s two-year comprehensive in-water noise survey to determine on-site permissible noise-exposure levels for divers. Some members of the research team performed similar work during the recovery of the turret from the USS Monitor. As a result of this and similar research, NSMRL has been named the bio-effects lead for DOD’s development of diver deterrence systems.

Monitoring the internal atmosphere that submariners breathe during long periods of submergence continues to be a focus of the lab. Onboard systems constantly measure critical levels of oxygen and carbon dioxide, but other substances in the atmosphere are potentially damaging to the crew’s health. Working with the Naval Sea Systems Command (NAVSEA) and the operational forces, NSMRL conducts the Submarine Atmosphere Health Assessment Program (SAHAP), which investigates new technologies for long-term air quality monitoring. As a result, small, passive air-sampling devices have been placed on many deployed submarines to provide operational commanders with timely information on airborne-contaminant levels while underway.

But NSMRL is also concerned with the ability of the crew to conduct their mission – the “human performance” element that is now the focus of the Navy’s “revolution in training.” Sonar operators aboard the new Virginia-class SSNs will be an immediate beneficiary of this research. Although moving the old “sonar shack” into the integrated command center of this highly-automated vessel will significantly improve tactical decision making, the ambient noise level of this high-activity area may mask some sonar signals. Thus, in conjunction with the Bose Corporation, NSMRL’s Joe Russotti has developed noise-canceling headphones that more accurately reproduce sonar signals than any unit currently in use. This same technology is also being used in stethoscopes for medical corpsmen and in insertable earplugs for combat troops and Special Operations Forces.

Photo caption follows
A U.S. Navy salvage diver pulls himself off the sea bottom onto the stage 20 feet above to make the safe decompression trip back home.

Virginia is also the first submarine whose Operational Requirements Document (ORD) specifically requires improved situational awareness (SA) for the Commanding Officer. Since there is currently no adequate measure of SA in a team-oriented submarine environment, Lieutenant Katie Shobe, MSC, USNR, developed a metric using concepts adapted from fighter-pilot research. Shobe’s metric proved out successfully in testing Virginia’s combat systems, and additional research is underway to see how the crew’s experience level affects SA performance. The results can be applied to training, developing new displays, and drafting operating procedures.

All of these programs are a reality now…but what about the future? Three new advanced technology programs at the laboratory will have immediate impact on tactical capabilities and crew safety.

With funding from the Office of Naval Research, NSMRL’s Dr. Tom Santoro is improving detection performance by developing a means to display sonar signals in three-dimensional auditory space. In addition to allowing sonar operators to hear short-duration transients more clearly, their “spatial orientation” within the headphones will indicate the bearing of the source.

Hearing loss is a national problem now costing two billion dollars in medical compensation annually. At NSMRL, Dr. Lynne Marshall is using sounds generated internally by the inner ear to detect the early onset of hearing loss, so that preventive measures can be taken.

Addressing another safety issue, CDR Wayne Horn, MC, USN, the lead researcher in submarine survival, is studying new technologies for extending crew endurance and making it easier to rescue survivors from the hypothetical sunken-submarine scenario that opened this article.

The Naval Submarine Medical Research Laboratory – a small command… with a huge impact.

Dr. Jerry Lamb is the Technical Director of the Naval Submarine Medical Research Laboratory. He received his Ph.D. from the University of Connecticut and has been in government service for fourteen years. Joe DiRenzo is a retired Coast Guard officer qualified in submarines and a Maritime Homeland Security Technical Director for Anteon Corporation’s Center for Security Strategies and Operations.