HOME

TheInfoList



OR:

The United States Navy Experimental Diving Unit (NEDU or NAVXDIVINGU) is the primary source of diving and
hyperbaric Hyperbaric medicine is medical treatment in which an ambient pressure greater than sea level atmospheric pressure is a necessary component. The treatment comprises hyperbaric oxygen therapy (HBOT), the medical use of oxygen at an ambient pressure ...
operational guidance for the US Navy. It is located within the Naval Support Activity Panama City in
Panama City Beach Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...
, Bay County, Florida.


Purpose

The functions of the Navy Experimental Diving Unit are to test and evaluate diving, hyperbaric, and other life-support systems and procedures, and to conduct research and development in biomedical and environmental
physiology Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemic ...
. NEDU also provides technical recommendations to the
Naval Sea Systems Command The Naval Sea Systems Command (NAVSEA) is the largest of the United States Navy's five "systems commands," or materiel (not to be confused with "material") organizations. From a physical perspective, NAVSEA has four shipyards for shipbuilding, c ...
to support operational requirements of the US armed forces.


History


Brooklyn Navy Yard

Experimental diving in the US Navy started in 1912 at the
Brooklyn Navy Yard The Brooklyn Navy Yard (originally known as the New York Navy Yard) is a shipyard and industrial complex located in northwest Brooklyn in New York City, New York (state), New York. The Navy Yard is located on the East River in Wallabout Bay, a ...
under the leadership of Chief Gunner George D. Stillson. Stillson's research program ultimately led to increasing diver capabilities from to over of depth based on Haldane's decompression work with the
Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by Kingdom of England, English and Kingdom of Scotland, Scottish kings from the early medieval period, the first major maritime engagements were foug ...
. This resulted in the first publication of the United States Navy Diving Manual and established the need for a facility dedicated to research and development of diving procedures. In 1915, Stillson's team was sent to salvage the ''F-4'' submarine. On these deep dives, the divers experienced the debilitating effects of
nitrogen narcosis Narcosis while diving (also known as nitrogen narcosis, inert gas narcosis, raptures of the deep, Martini effect) is a reversible alteration in consciousness that occurs while diving at depth. It is caused by the anesthetic effect of certain ...
leading them to try the addition of
helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...
to their breathing mix. The navy salvage operations then came under the direction of Warrant Gunner C. L. Tibbals who led teams through the salvage of the ''S-51'' in 1925 and ''S-4'' in 1927 further establishing the naval need for equipment, training, and procedures for rescue operations.


Washington Navy Yard

NEDU was established in 1927 at the
Washington Navy Yard The Washington Navy Yard (WNY) is the former shipyard and ordnance plant of the United States Navy in Southeast Washington, D.C. It is the oldest shore establishment of the U.S. Navy. The Yard currently serves as a ceremonial and administra ...
. Early developments for the unit involved evaluation and testing of the Submarine Escape Lung (
Momsen lung The Momsen lung was a primitive underwater rebreather used before and during World War II by American submariners as emergency escape gear. It was invented by Charles Momsen (nicknamed "Swede"). Submariners trained with this apparatus in an de ...
) and the McCann Rescue Bell. This work was done by
Charles Momsen Charles Bowers Momsen (June 21, 1896 – May 25, 1967), nicknamed "Swede", was born in Flushing, New York. He was an American pioneer in submarine rescue for the United States Navy, and he invented the underwater escape device later called the " ...
and Allan McCann. In 1929, Momsen received the Navy Distinguished Service Medal for personally testing the device at a depth of 200 feet (61 m). Techniques used for the rescue of submariners aboard the '' USS Squalus'' were developed by Momsen and McCann in their time at NEDU. This work lead to the rescue and recovery of 33 crewmen. Momsen and McCann received a Letter of Commendation from
President of the United States The president of the United States (POTUS) is the head of state and head of government of the United States of America. The president directs the Federal government of the United States#Executive branch, executive branch of the Federal gove ...
Franklin D. Roosevelt for the ''Squalus'' effort. The first medical staff were introduced to the facility in the mid-1930s when Charles W Shilling, Albert R Behnke, and OE Van der Aue began work. Their early work improved the prevention and treatment of
decompression sickness Decompression sickness (abbreviated DCS; also called divers' disease, the bends, aerobullosis, and caisson disease) is a medical condition caused by dissolved gases emerging from solution as bubbles inside the body tissues during decompressi ...
with the inclusion of
oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...
rather than air. Through
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
, work continued on decompression and
oxygen toxicity Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen () at increased partial pressures. Severe cases can result in cell damage and death, with effects most often seen in the central nervous system, lu ...
. Through the 1950s NEDU tested equipment and further refined procedures for divers including the US Navy 1953 decompression table. From 1957 to 1962 was the beginnings of
saturation diving Saturation diving is diving for periods long enough to bring all tissues into equilibrium with the partial pressures of the inert components of the breathing gas used. It is a diving mode that reduces the number of decompressions divers workin ...
under the leadership of
Captain Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police department, election precinct, e ...
George F. Bond of the Naval Submarine Medical Research Laboratory and the Genesis Project. Genesis D was performed at NEDU in 1963. Bond then went on to head the SEALAB I saturation project in 1964. Robert D. Workman published a novel method to calculate decompression schedules in 1965 that involved estimating the limiting values of excess tissue supersaturation. Work continued in deep saturation dives, equipment testing as well as thermal protection and physiology research throughout the 1960s and early 1970s. The MK 1 lightweight mask was a modification of the commercial Kirby Morgan band mask, which NEDU tested in the early 1970s, and which was suitable for both air and mixed gas operations to 300 feet, and provided voice communications. It was adopted for Navy service after modifications recommended by NEDU were implemented.


Naval Support Activity Panama City

In 1975, NEDU relocated to its current location in Panama City, Florida. NEDU began a project to modernize Stillson's MK V surface supplied diving system which had been in service since 1916 in the early 1970s, and developed, tested, and certified the replacement Mark 12 Surface Supplied Diving System which was taken into service in 1985, and eventually its replacement the Mark 21/ Superlight 17 in the 1970s and 1980s, adopted in 1993. NEDU developed the MK 14 Closed-Circuit Saturation Diving System in the 1970s. This system is used for diving operations from a closed divin bell and a saturation system. NEDU comprehensively tested and evaluated the MK 11 rebreather in the 1970s. NEDU conducts at least one
saturation dive Saturation diving is diving for periods long enough to bring all tissues into equilibrium with the partial pressures of the inert components of the breathing gas used. It is a diving mode that reduces the number of decompressions divers workin ...
per year. These dives were used, amongst other things, to evaluate decompression and recompression procedures, equipment, carbon dioxide absorbents, as well as active and passive
thermal protection A thermal cutoff is an electrical safety device (either a thermal fuse or thermal switch) that interrupts electric current when heated to a specific temperature. These devices may be for one-time use (a thermal fuse), or may be reset manually or ...
. Many of these tests included ongoing evaluations of commercially available diving equipment. NEDU evaluated the Jack Browne lightweight mask for shallow water diving on several occasions. The mask was in service from World War II through the late 1970s. By 1978 NEDU determined the mask was no longer suitable for intensive diving operations and it was phased out in the 1980s. NEDU tested and certified the commercially produced Mk 15 rebreather for use by Navy Special Forces in 1980, and developed new constant oxygen partial pressure decompression tables to use with the it, as standard open circuit tables could not be used. This was followed by evaluation of the Mk 16 rebreather, an upgrade of the Mk 15 with a low magnetic signal suitable for
explosive ordnance disposal Bomb disposal is an explosives engineering profession using the process by which hazardous explosive devices are rendered safe. ''Bomb disposal'' is an all-encompassing term to describe the separate, but interrelated functions in the milit ...
(EOD) operations. In 1998, the Naval Medical Research Center's diving biomedical and development group was transferred to NEDU. In response to the overseas military needs, NEDU focused on warm water diving from 1999 to 2002. This guidance to the Naval Special Warfare community influences operational needs on an ongoing basis. NEDU divers were essential to the recovery of artifacts from the wreck of the USS ''Monitor'' in 2001 and 2002. In 2002, certification of the Mark 16 Mod 1 rebreather was completed following improvement of systems including, extension of the working limit to , new decompression tables for both nitrogen-oxygen and helium-oxygen diving including new repetitive diving capabilities for helium-oxygen, test of an Emergency Breathing System with communications, the addition of an integrated buoyancy compensation device, and an improved full face mask. In 2004, NEDU contributed to operational guidance for diving in harsh contaminated environments. NEDU has continued research into
oxygen toxicity Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen () at increased partial pressures. Severe cases can result in cell damage and death, with effects most often seen in the central nervous system, lu ...
utilizing the US Navy Mark 16 Mod 1. Development of breathing systems, thermal protection, and decompression procedures for
SEAL Delivery Vehicle The SEAL Delivery Vehicle (SDV) is a crewed submersible and a type of swimmer delivery vehicle used to deliver United States Navy SEALs and their equipment for special operations missions. It is also operated by the Royal Navy's Special Boat Ser ...
s and the
Advanced SEAL Delivery System The Advanced SEAL Delivery System (ASDS) was a midget submarine operated by the United States Navy and United States Special Operations Command. It provided stealthy submerged transportation for United States Navy SEALs from the decks of nuclear ...
is ongoing. In 2011, divers completed a 1,000 fsw saturation dive to evaluate the new Navy's Saturation Fly-Away Diving System (SAT FADS). The SAT FADS was designed in 2006 as a portable replacement of two decommissioned Pigeon-class submarine rescue vessels. In June 2019, CDR Kiah Rahming took up his appointment as
Commanding Officer The commanding officer (CO) or sometimes, if the incumbent is a general officer, commanding general (CG), is the officer in command of a military unit. The commanding officer has ultimate authority over the unit, and is usually given wide latit ...
of NEDU.


Facilities


Ocean simulation facility

The Ocean Simulation Facility (OSF) simulates
ocean The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wo ...
conditions to a maximum pressure equivalent of seawater at any
salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...
level. The chamber complex consists of a wet chamber and five interconnected dry living/working chambers totaling of space. Wet and dry chamber temperatures can be set from . Equipped with the latest data acquisition capability, the OSF can accommodate a wide range of complex experiments including diver biomedical studies and testing of humans as well as small submersible vehicles and other machines in the wet chamber. Saturation dives can be performed for more than 30 days of continuous exposure in the OSF. For human and equipment testing underwater over extended periods, divers use the dry chambers as comfortable living quarters, from which they can make diving excursions into the wet chamber. The dry chambers are also capable of altitude simulation studies to heights of .


Experimental test pool

The Experimental Test Pool is a capacity freshwater tank measuring by by deep, capable of sustaining temperatures from . It is designed and constructed for manned, shallow water testing and for supporting workup dives for the Ocean Simulation Facility. The test pool is supported by a fully instrumented medical and engineering deck, from which the safety of both divers and test equipment can be monitored. The facility can accommodate a wide range of experiments, from biomedical studies of diver thermal and workload conditions to equipment studies of submersible devices. The test pool has a communications suite, full video capability, real-time computerized data acquisition and analysis, and pressure and gas monitoring. The depth is sufficient to allow divers to maintain an oxygen partial pressure of 1.3
bar Bar or BAR may refer to: Food and drink * Bar (establishment), selling alcoholic beverages * Candy bar * Chocolate bar Science and technology * Bar (river morphology), a deposit of sediment * Bar (tropical cyclone), a layer of cloud * Bar (un ...
on their breathing apparatus while immersed and riding a bicycle ergometer.


Environmental chamber

The Environmental Chamber is capable of simulating a broad range of temperatures from ,
humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity dep ...
from 5 to 95%, and wind velocity from . The chamber is instrumented to conduct physiological studies and to test various types of equipment.


Experimental diving facility

The Experimental Diving Facility (EDF) simulates unmanned pressure conditions to sea water and temperatures can be set from . As a complement to the Ocean Simulation Facility, the EDF is used to conduct unmanned testing and evaluation of diving and hyperbaric chamber systems and components. All diving practices and procedures are tested to determine their safety, conformance to established standards, and operational suitability and limits.


Class 100,000 clean room

Operated by certified technicians, the Class 100,000 Clean Room performs a variety of cleaning and testing tasks: oxygen cleaning of piping, valves, regulators, tanks, and filters, as well as hydrostatic testing up to . All components used in diving life-support systems are cleaned and certified to meet military standards.


Gas analysis lab

The gas analysis laboratory is equipped for the precise analysis of gases, and it is used to evaluate diving-related problems such as offgassing and contaminant control. The laboratory's analytical capabilities include
gas chromatography Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, ...
,
mass spectrometry Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a '' mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is u ...
, and
infrared spectroscopy Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or function ...
. The facility is currently used to develop reliable and rapid screening methods and analyzers for the Fleet.


Cardiopulmonary lab

The cardiopulmonary laboratory consists of machines that perform a variety of
respiratory The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies gre ...
function tests and aerobic performance measurements that are often recorded before and after pressure and/or thermal exposure.


Library

The NEDU
Library A library is a collection of materials, books or media that are accessible for use and not just for display purposes. A library provides physical (hard copies) or digital access (soft copies) materials, and may be a physical location or a vi ...
contains over 120,000
document A document is a written, drawn, presented, or memorialized representation of thought, often the manifestation of non-fictional, as well as fictional, content. The word originates from the Latin ''Documentum'', which denotes a "teaching" o ...
s on diving medicine, engineering, and history from around the world. Many of the NEDU
publications To publish is to make content available to the general public.Berne Con ...
have been scanned and are available online at the Rubicon Research Repository. Other articles can be found in the
Duke University Medical Center Duke University Hospital is a 957-acute care bed academic tertiary care facility located in Durham, North Carolina. Established in 1930, it is the flagship teaching hospital for the Duke University Health System, a network of physicians and ho ...
Archive An archive is an accumulation of historical records or materials – in any medium – or the physical facility in which they are located. Archives contain primary source documents that have accumulated over the course of an individual ...
finding aid A finding aid, in the context of archival science, is an organization tool, a document containing detailed, indexed, and processed metadata and other information about a specific collection of records within an archive. Finding aids often consist ...
s of the Undersea and Hyperbaric Medical Society library collection.


Personnel

The 120 person NEDU Team includes highly qualified and experienced military divers with a combined 1,000 man-years of diving experience: Sea-Air-Land (SEAL), Explosive Ordnance Disposal (EOD), Salvage, Saturation, Seabee, Diving Officer, and Diving Medical Officer (DMO), Ph.D. scientists,
engineer Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the l ...
s, various science-degreed professionals and support personnel.


In media

* "The Mystery of the Bends," a 1992 episode of the PBS television series '' Return to the Sea'', includes a profile of the United States Navy Experimental Diving Unit.


References


External links

* *
NEDU Blog

NEDU question and answer on the Scubaboard.com forum
*
''Return to the Sea'' Episode 203 "The Mystery of the Bends" at OceanArchives
(
Fair use Fair use is a doctrine in United States law that permits limited use of copyrighted material without having to first acquire permission from the copyright holder. Fair use is one of the limitations to copyright intended to balance the intere ...
policy for video a
OceanArchives
{{coord missing, Florida Diving medicine organizations Diving organizations Armed forces diving United States Navy installations Buildings and structures in Bay County, Florida United States Navy organization