United States Navy Experimental Diving Unit

The United States Navy Experimental Diving Unit dures for rescue operations.[2] (NEDU or NAVXDIVINGU) is the primary source of diving and hyperbaric operational guidance for the US [1][2][3] Navy. It is located within the Naval Support Ac- 2.2 Washington Navy Yard tivity Panama City in Panama City Beach, Bay County, Florida.[3] NEDU was established in 1927 at the Washington Navy Yard.[1][2] 1 Mission and vision

NEDU describes its mission as: “The Navy Experimen- tal Diving Unit tests and evaluates diving, hyperbaric, and other life-support systems and procedures, and conducts research and development in biomedical and environmental physiology. NEDU provides technical rec- ommendations based upon knowledge and experience, to Commander, Naval Sea Systems Command to support operational requirements of our armed forces.”[3] The vision for NEDU is stated to be: “The Navy Ex- perimental Diving Unit will be the most credible and re- spected research, development, and test and evaluation center for diving as well as the focal point of leadership for biomedical and bioengineering solutions for undersea military operations.”[3]

2 History A Momsen lung in use during training 2.1 Brooklyn Navy Yard Early developments for the unit involved evaluation and Experimental diving in the US Navy started in 1912 at testing of the Submarine Escape Lung (Momsen lung) the Brooklyn Navy Yard under the leadership of Chief and the McCann Rescue Bell.[2] This work was done by Gunner George D. Stillson.[1] Stillson’s research program Charles Momsen and Allan McCann. In 1929, Momsen ultimately led to increasing diver capabilities from 60 received the Navy Distinguished Service Medal for per- feet (18 m) to over 300 feet (91 m) of depth based sonally testing the device at a depth of 200 feet (61 m). on Haldane’s decompression work with the Royal Navy. Techniques used for the rescue of submariners aboard the This resulted in the first publication of the United States USS Squalus were developed by Momsen and McCann in Navy Diving Manual and established the need for a fa- their time at NEDU.[2][6][7] This work lead to the rescue cility dedicated to research and development of diving and recovery of 33 crewmen.[6] Momsen and McCann procedures.[1][4][5] received a Letter of Commendation from President of the United States Franklin D. Roosevelt for the Squalus In 1915, Stillson’s team was sent to salvage the F-4 sub- [6] marine. On these deep dives, the divers experienced the effort. debilitating effects of nitrogen narcosis leading them to The first medical staff were introduced to the facil- try the addition of helium to their breathing mix.[2] The ity in the mid-1930s when Charles W Shilling, Albert navy salvage operations then came under the direction of R Behnke, and OE Van der Aue began work. Their Warrant Gunner C. L. Tibbals who led teams through the early work improved the prevention and treatment of salvage of the S-51 in 1925 and S-4 in 1927 further estab- decompression sickness with the inclusion of oxygen lishing the naval need for equipment, training, and proce- rather than air.[1][8][9]

1 2 3 FACILITIES

Through World War II, work continued on decompres- biomedical and development group was transferred to sion and oxygen toxicity.[10][11] NEDU.[1][26] Through the 1950s NEDU tested equipment and further In response to the overseas military needs, NEDU fo- refined procedures for divers including the US Navy 1953 cused on warm water diving from 1999 to 2002.[27] This decompression table.[12][13] guidance to the Naval Special Warfare community influ- [1] From 1957 to 1962 was the beginnings of saturation div- ences operational needs on an ongoing basis. ing under the leadership of Captain George F. Bond of NEDU divers were essential to the recovery of artifacts the Naval Submarine Medical Research Laboratory and from the ex-USS Monitor in 2001 and 2002.[1][28] [1][14] the Genesis Project. Genesis D was performed at In 2002, certification of the Mark 16 Mod 1 rebreather NEDU in 1963.[1][15] Bond then went on to head the [16] was completed following improvement of systems in- SEALAB I saturation project in 1964. cluding, extension of the working limit to 300 feet (91 Robert D. Workman published a novel method to m), new decompression tables for both nitrogen-oxygen calculate decompression schedules in 1965 that in- and helium-oxygen diving including new repetitive div- volved estimating the limiting values of excess tissue ing capabilities for helium-oxygen, test of an Emergency supersaturation.[17] Breathing System with communications, the addition of an integrated buoyancy compensation device, and an im- Work continued in deep saturation dives, equipment test- [1][29] ing as well as thermal protection and physiology research proved full face mask. throughout the 1960s and early 1970s.

2.3 Naval Support Activity Panama City

In 1975, NEDU relocated to its current location in Panama City, Florida.[1]

SEALs using SEAL Delivery Vehicle

In 2004, NEDU contributed to operational guidance for diving in harsh contaminated environments.[30] NEDU has continued research into oxygen toxicity uti- lizing the US Navy Mark 16 Mod 1.[31][32] Development of breathing systems, thermal protection, and decompression procedures for SEAL Delivery Ve- hicles and the Advanced SEAL Delivery System is US Navy Diver using Kirby Morgan 37 diving helmet ongoing.[33][34] In 2011, divers completed a 1,000 fsw saturation dive to NEDU tested and evaluated the replacement of Stillson’s evaluate the new Navy’s Saturation Fly-Away Diving Sys- Mark V as the US Navy standard diving dress, the Mark tem (SAT FADS).[35] The SAT FADS was designed in 12 Surface Supplied Diving System, and eventually its re- 2006 as a portable replacement of two decommissioned placement the Mark 21/ Superlight 17 in the 1970s and Pigeon-class submarine rescue vessels.[35] 1980s.[1][18][19] Evaluation and testing of new breathing apparatus and ap- NEDU conducts at least one saturation dive per year. plication of other technologies for diving is key to their These dives were used, amongst other things, to evalu- mission.[36][37] ate decompression and recompression procedures, equipment, carbon dioxide absorbents, as well as active and passive thermal protection.[20][21][22] Many of these tests included ongoing evaluations of commercially available diving equipment.[23][24][25] 3 Facilities In 1998, the Naval Medical Research Center’s diving 3.3 Environmental chamber 3

NEDU experimental test pool

(4.6 m) by 30 ft (9.1 m) by 15 ft (4.6 m) deep, capable of sustaining temperatures from 34 to 105 °F (1 to 41 °C). 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 moni- tored. 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 NEDU Ocean Simulation Facility and analysis, and pressure and gas monitoring.[39] The depth is suﬃcient to allow divers to maintain an oxy- 3.1 Ocean simulation facility gen partial pressure of 1.3 bar on their breathing apparatus while immersed and riding a bicycle ergometer.[31][32] The Ocean Simulation Facility (OSF) simulates ocean conditions to a maximum pressure equivalent of 2,250 feet (690 m) seawater (fsw) at any salinity level. 3.3 Environmental chamber The chamber complex consists of a 55,000-US-gallon (210,000 L) wet chamber and ﬁve interconnected dry living/working chambers totaling 3,300 cubic feet (93 m3) of space. Wet and dry chamber temperatures can be set from 28 to 104 °F (−2 to 40 °C). Equipped with the lat- est 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 quar- ters, from which they can make diving excursions into the wet chamber. The dry chambers are also capable of altitude simulation studies to heights of 150,000 feet NEDU environmental chamber (46,000 m).[38] The Environmental Chamber is capable of simulating a broad range of temperatures from 0 to 130 °F (−18 to 54 3.2 Experimental test pool °C), humidity from 5 to 95%, and wind velocity from 0 to 20 mph (0 to 32 km/h). The chamber is instrumented The Experimental Test Pool is a 50,000-US-gallon to conduct physiological studies and to test various types (190,000 L) capacity freshwater tank measuring 15 ft of equipment.[40] 4 4 PERSONNEL

3.4 Experimental diving facility

NEDU gas analysis lab

3.6 Gas analysis lab

NEDU experimental diving facility The gas analysis laboratory is equipped for the pre- cise analysis of gases, and it is used to evaluate diving- The Experimental Diving Facility (EDF) simulates un- related problems such as oﬀgassing and contaminant con- manned pressure conditions to 1,640 feet (500 m) sea trol. The laboratory’s analytical capabilities include gas water and temperatures can be set from 28 to 110 °F chromatography, mass spectrometry, and infrared spec- (−2 to 43 °C). As a complement to the Ocean Simula- troscopy. The facility is currently used to develop reli- tion Facility, the EDF is used to conduct unmanned test- able and rapid screening methods and analyzers for the ing and evaluation of diving and hyperbaric chamber sys- Fleet.[44][45][46] tems and components. All diving practices and procedures are tested to determine their safety, conformance to established standards, and operational suitability and 3.7 Cardiopulmonary lab limits.[41][42] The cardiopulmonary laboratory consists of machines that perform a myriad of respiratory function tests 3.5 Class 100,000 clean room and aerobic performance measurements that are of- ten recorded before and after pressure and/or thermal exposure.[47]

3.8 Library

The NEDU Library contains over 120,000 documents on diving medicine, engineering, and history from around the world.[48] Many of the NEDU publications have been scanned and are available online at the Rubicon Re- search Repository.[49] Other articles can be found in the Duke University Medical Center Archive ﬁnding aids of the Undersea and Hyperbaric Medical Society library collection.[50]

NEDU Class 100,000 clean room 4 Personnel

Operated by certified technicians, the Class 100,000 The 120 person NEDU Team includes highly qualified Clean Room performs a variety of cleaning and test- and experienced military divers with a combined 1,000 ing tasks: oxygen cleaning of piping, valves, regulators, man-years of diving experience: Sea-Air-Land (SEAL), tanks, and filters, as well as hydrostatic testing up to Explosive Ordnance Disposal (EOD), Salvage, Satura- 10,000 psi (69,000 kPa). All components used in div- tion, Seabee, Diving Officer, and Diving Medical Offi- ing life-support systems are cleaned and certified to meet cer (DMO), Ph.D. scientists, engineers, various science- military standards.[43][44][45] degreed professionals and support personnel.[51] 5

5 See also [14] Lonsdale, MV. “Evolution of US Navy Diving”. Re- trieved 2008-09-09.

6 References [15] Workman, Robert D; Bond, George F; Mazzone, Walter F (1967). “Prolonged exposure of animals to pressur- [1] Tranchemotagne, M (2003). “NEDU Celebrates 75 ized normal and synthetic atmospheres”. Naval Subma- Years” (PDF). Faceplate. 7 (1): 4–5. Retrieved 2008- rine Medical Research Lab Technical Report (NSMRL– 09-09. 374). Retrieved 2010-01-29.

[2] Carter Jr, RC (1977). “Pioneering Inner Space: The Navy [16] Miller, James W; Koblick, Ian G (1984). Living and Experimental Diving Unit’s First 50 Years”. US Navy Ex- working in the sea. Best Publishing Company. p. 432. perimental Diving Unit Technical Report. NEDU-1-77. ISBN 1-886699-01-1. Retrieved 2008-09-09. [17] Workman, RD (1965). “Calculation of decompression [3] NEDU. “Navy Experimental Diving Unit”. Navy Experi- schedules for nitrogen-oxygen and helium-oxygen dives”. mental Diving Unit. Retrieved 2008-09-09. US Navy Experimental Diving Unit Technical Report. NEDU-6-65. Retrieved 2008-09-09. [4] Stillson, GD (1915). “Report in Deep Diving Tests.”. US Bureau of Construction and Repair, Navy Department. [18] Coulombe, MA (1978). “MK 12 Surface Supported Div- Technical Report. Retrieved 2008-09-09. ing System (MK 12 SSDS) Mixed Gas, Technical Evalu- ation”. US Navy Experimental Diving Unit Technical Re- [5] Boycott, A. E.; G. C. C. Damant; J. S. Haldane (1908). port. NEDU-19-78. Retrieved 2008-09-09. “The Prevention of Compressed-air Illness”. J. Hygiene. 8 (3): 342–443. doi:10.1017/S0022172400003399. PMC [19] Curley, MD (1986). “Human Factors Evaluation of the 2167126 . PMID 20474365. Retrieved 2008-09-09. Superlite 17B Helmet in the Surface- Supplied, Open- Circuit Mode”. US Navy Experimental Diving Unit Tech- [6] Maas, Peter (1999). The Terrible Hours: The Man Be- nical Report. NEDU-11-85. Retrieved 2008-09-09. hind the Greatest Submarine Rescue in History. New York: HarperCollins Publishers. ISBN 978-0-06-019480-2. [20] Thalmann, E. D. (1985). “Development of a Decompres- OCLC 41504915. sion Algorithm for Constant Oxygen Partial Pressure in [7] Momsen, C. (1942). “Report on Use of Helium Oxygen Helium Diving”. US Navy Experimental Diving Unit Tech- Mixtures for Diving”. US Naval Experimental Diving Unit nical Report. NEDU-1-85. Retrieved 2008-09-09. Technical Report (42–02). Retrieved 2008-09-09. [21] Zumrick Jr, JL (1984). “Manned Evaluation of the MK- [8] Behnke, AR; Willmon, TL (1940). “Preliminary Re- 15 UBA (Underwater Breathing Apparatus) Canister Du- port on Aeroembolism and Equipment for Oxygen Inhala- ration in 13 C Water Using a Resting Diver Scenario”. US tion”. US Navy Experimental Diving Unit Technical Re- Navy Experimental Diving Unit Technical Report. NEDU- port. NEDU-1-40. Retrieved 2008-09-09. 2-84. Retrieved 2008-09-09.

[9] Van Der Aue, OE; White Jr, WA; Hayter, R; Brinton, [22] Clarke, JR; Thompson, LD; Godgrey Jr, RJ (1998). “Lot ES; Kellar, RJ (1945). “Physiologic Factors Underlying Variability of Sofnolime 408 Carbon Dioxide Absorbent the Prevention and Treatment of Decompression Sick- When Tested in the Cold”. US Navy Experimental Diving ness”. US Navy Experimental Diving Unit Technical Re- Unit Technical Report. NEDU-01-98. Retrieved 2008- port. NEDU-1-45. Retrieved 2008-09-09. 09-09.

[10] Behnke A. R.; Johnson F. S.; Poppen J. R. & Motley E. P. [23] Middleton, JR (1980). “Evaluation of Commercially (1935). “The eﬀect of oxygen on man at pressures from Available Buoyancy Compensators”. US Navy Experimen- 1 to 4 atmospheres”. Am J Physiol. 110 (3): 565–572. tal Diving Unit Technical Report. NEDU-1-80. Retrieved Retrieved 2008-09-09. 2008-09-09. [11] Yarbrough, OD; Welham, W; Brinton, ES; Behnke, AR [24] Middleton, JR (1980). “Evaluation of Commercially (1947). “Symptoms of Oxygen Poisoning and Limits of Available Open Circuit Scuba Regulators”. US Navy Ex- Tolerance at Rest and at Work”. US Navy Experimental perimental Diving Unit Technical Report. NEDU-2-80. Diving Unit Technical Report. NEDU-1-47. Retrieved Retrieved 2008-09-09. 2008-09-09.

[12] Fulton, HT; Welham, W; Blockwick, TN (1951). [25] Sterba, JA; Hanson, RS; Stiglich, JF (1989). “Insulation, “Nitrogen-Oxygen Self-Contained Underwater Breathing Compressibility and Absorbency of Dry Suit Undergar- Equipment”. US Navy Experimental Diving Unit Technical ments”. US Navy Experimental Diving Unit Technical Re- Report. NEDU-8-51. Retrieved 2008-09-09. port. NEDU-10-89. Retrieved 2008-09-09.

[13] Lanphier, EH; Dwyer, JV (1954). “Diving with Self- [26] Department of the Navy (1995). “Defense Base Closure Contained Underwater Breathing Apparatus. Reports 1 - and Realignment Commission 1995 Report to the Presi- 11”. US Navy Experimental Diving Unit Technical Report. dent : Naval Medical Research Institute, Bethesda, Mary- NEDU-54-1 to 11. Retrieved 2008-09-09. land”. Retrieved 2008-09-09. 6 7 EXTERNAL LINKS

[27] Long, ET; O'Connor, PE; Liberatore, TC (2003). [41] NEDU. “Navy Experimental Diving Unit Experimental “Development of Exposure Guidance for Warm Water experimental diving facility”. Navy Experimental Diving Diving. Volume 1. Physiology and Endurance”. US Navy Unit. Retrieved 2008-09-09. Experimental Diving Unit Technical Report. NEDU-03- 11. Retrieved 2008-09-09. [42] “Procedures for evaluating diving equipment involved in a diving related mishap”. Navxdivingu Instruction 5102.1A. [28] Cavey, R (2002). “USS Monitor turret recovery” (PDF). Navy Experimental Diving Unit. 2003. Retrieved 2008- Faceplate. 6 (2): 3–5. Retrieved 2008-09-09. 09-30.

[29] Hedricks, CS; Stanek, SJ (2002). “Evaluation of the [43] NEDU. “Navy Experimental Diving Unit Experimental KMS 48 Replacement Full Face Mask with the Emer- class 100,000 clean room”. Navy Experimental Diving gency Breathing System for Use with MK 16 MOD 1 Un- Unit. Retrieved 2008-09-09. derwater Breathing Apparatus”. US Navy Experimental Diving Unit Technical Report. NEDU-02-17. Retrieved [44] NAVSEA (2005). “Cleaning and gas analysis for div- 2008-09-09. ing applications handbook”. NAVSEA Technical Man- ual. NAVAL SEA SYSTEMS COMMAND. SS521-AK- [30] US Naval Sea Systems Command (2004). “Guidance for HBK-010. Retrieved 2008-09-12. diving in contaminated waters”. US Navy Contaminated Water Manual. SS521-AJ-PRO-010. Retrieved 2008-09- [45] Rosales, KR; Shoffstall, MS; Stoltzfus, JM (2007). 09. “Guide for Oxygen Compatibility Assessments on Oxy- gen Components and Systems”. NASA, Johnson Space [31] Shykoff, BE (2005). “Repeated Six-Hour Dives 1.35 Center Technical Report. NASA/TM-2007-213740. Re- ATM Oxygen Partial Pressure”. US Navy Experimental trieved 2008-09-12. Diving Unit Technical Report. NEDU-05-20. Retrieved 2008-09-09. [46] NEDU. “Navy Experimental Diving Unit Experimental gas analysis lab”. Navy Experimental Diving Unit. Re- [32] Shykoff, BE (2007). “Pulmonary Effects of Eight-Hour trieved 2008-09-09. MK 16 MOD 1 Dives”. US Navy Experimental Diving Unit Technical Report. NEDU-07-10. Retrieved 2008-09-09. [47] NEDU. “Navy Experimental Diving Unit Experimental cardiopulmonary lab”. Navy Experimental Diving Unit. [33] Carlson, NA; Warkander, DE (2005). “Carbon Diox- Retrieved 2008-09-09. ide Washout of an Emergency Breathing System Mask Modified for Use in the Advanced Seal Delivery Sys- [48] NEDU. “Navy Experimental Diving Unit Library”. Navy tem (ASDS) Trainer”. US Navy Experimental Diving Unit Experimental Diving Unit. Retrieved 2008-09-09. Technical Report. NEDU-05-13. Retrieved 2008-09-09. [49] Rubicon Foundation. “NEDU Collection”. Retrieved [34] Nuckols, ML; Chao, JC; Swiergosz, MJ (2005). “Manned 2008-09-12. Evaluation of a Diver Heater for SDV Applications Using Hydrogen Catalytic Reactions”. US Navy Experimental [50] Duke University Medical Center Archives. “Undersea and Diving Unit Technical Report. NEDU-05-08. Retrieved Hyberbaric Medical Society Collection”. Duke University 2008-09-09. Medical Center Archives. Retrieved 2008-09-12.

[35] Carson, Daniel (2011-04-30). “Divers complete test of [51] NEDU. “Navy Experimental Diving Unit Personnel”. new Navy saturation diving system”. Panama City News Navy Experimental Diving Unit. Retrieved 2008-09-11. Herald. Retrieved 2011-05-03.

[36] Swiergosz, MJ; Steckel, RJ (2005). “Limited Unmanned Evaluation of the DIVEX SLS MK IV Backpack at Sea 7 External links Level and 1000 FSW”. US Navy Experimental Diving Unit Technical Report. NEDU-05-07. Retrieved 2008-09-09. • NEDU. “Navy Experimental Diving Unit”. Re- trieved 2008-09-09. [37] Nuckols, M. L.; Chao J. C.; Swiergosz M. J. (2005). “Manned Evaluation of a Prototype Composite Cold Wa- • NEDU Technical Reports ter Diving Garment Using Liquids and Superinsulation Aerogel Materials”. US Naval Experimental Diving Unit • NEDU Blog Technical Report. NEDU-05-02. Retrieved 2008-09-09. • NEDU question and answer on the Scubaboard.com [38] NEDU. “Navy Experimental Diving Unit Ocean Simula- forum tion Facility”. Navy Experimental Diving Unit. Retrieved 2008-09-09. • Harris, GL. “Navy Experimental Diving Unit his- [39] NEDU. “Navy Experimental Diving Unit Experimental tory”. Retrieved 2008-09-09. test pool”. Navy Experimental Diving Unit. Retrieved 2008-09-09.

[40] NEDU. “Navy Experimental Diving Unit Experimen- tal environmental chamber”. Navy Experimental Diving Unit. Retrieved 2008-09-09. 7

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