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Submarine Atmospheric Contaminant Scrubbing Technology


RT&L FOCUS AREA(S): General Warfighting Requirements

TECHNOLOGY AREA(S): Ground / Sea Vehicles

OBJECTIVE: To provide passive atmospheric contaminant scrubbing technologies to reduce and/or eliminate gas contaminants from 1 to 6 atmospheres absolute (ata).

DESCRIPTION: When a DISabled SUBmarine (DISSUB) event occurs, several dangerous and potentially lethal atmospheric contaminants can be introduced from fire, battery malfunctions, and other potential sources. These contaminants, if not appropriately managed or removed, can limit the time DISSUB survivors can await rescue. At this time, the submarine force has limited means of removing dangerous atmospheric contaminants, beyond Carbon Dioxide (CO2), from the DISSUB atmosphere when the internal compartment is either pressurized or there is insufficient available power to utilize other scrubbing technologies. Currently there is no known commercially available technology to passively scrub these contaminants.

The concept of operations (CONOPS) for a DISSUB rescue begin with a senior onboard survivor measuring and monitoring specific atmospheric containments via the USN DISSUB Guard Books. These guard books provide the procedures necessary to support DISSUB survivors in awaiting rescue by rescue forces for a minimum of seven days after the DISSUB event. Additionally, the Guard Books enable the survivors to determine when the atmosphere has been contaminated to a point that it is no longer safe to wait for rescue and therefore escape is required. While awaiting rescue is the preferred method for survivors, the inability to lower or eliminate specific hazardous contaminants may require survivors to attempt escape. Oxygen (O2) is added to and CO2 is removed from the internal compartment atmosphere passively via Chlorite candles and Lithium Hydroxide (LiOH) scrubber curtains, respectively. However, there are an additional seven constituents that have been identified by medical personnel as being dangerous to DISSUB survivors when subjected to prolonged exposure to elevated levels. These constituents are defined as the Submarine Escape Action Limit (SEAL) gases and are Carbon Monoxide (CO), Hydrogen Cyanide (HCN), Ammonia (NH3), Chlorine (Cl2), Hydrogen Chloride (HCl), Sulfur Dioxide (SO2) and Nitrogen Dioxide (NO2).

The program office desires the development of a technology that can provide the ability to passively lower and/or eliminate the 7 SEAL gases identified from a DISSUB internal compartment. In the event of a DISSUB, it is anticipated that the submarine will not have sufficient available power to support an active system. Additionally, the use of a passive system will reduce the production of Carbon Dioxide that would result from survivors using a manually operated system. Due to onboard constraints, the solution(s) should minimize the footprint of the equipment and maintenance requirements. Additionally, to reduce survivor physical stressors and CO2 generation, the solutions(s) should minimize human system operations while also remaining cognizant of the limited power that may be available. Note that stand-alone battery power for the equipment is acceptable, but the use of Lithium Ion (LIO) batteries is not. Due to internal compartment space constraints, the proposed solution should minimize, as much as practical, the footprint of any required installed equipment as well as maintenance and lifecycle cost requirements.

In terms of technology development efforts, the threshold is the ability to reduce contaminant levels below SEAL 2 levels as quickly as possible and maintain the contaminant levels below SEAL 2 levels for a minimum of seven days. The SEAL 2 levels are CO 150ppm, HCN 15 ppm, NH3 125 ppm, Cl2 2.5ppm, HCl 35 ppm, SO2 30 ppm, and NO2 10 ppm. The objective is the ability to reduce and maintain contaminant levels at or below SEAL 1 levels for a minimum of seven days (CO 125ppm; HCN 10 ppm; NH3 75 ppm; Cl2 1 ppm; HC1 20 ppm; SO2 20 ppm; CO2 5 ppm). Testing will be conducted via bench-test in a simulated environment comparable to the anticipated operational environment at NSWC Philadelphia.

In addition to being a safety and duty of care issue, continued advancement and modernization of the USN Submarine Escape and Rescue Program is considered an Assistant Secretary of the Navy core field in support of the larger Undersea Warfare, and directly aligns to both the National Defense Strategy and the Submarine Commander's Intent by defending the homeland; enabling interagency counterparts to advance U.S. influence and national security interests; ensuring USN submarine warfighting readiness and survivability; and strengthening alliances and attracting new partners. The latter was highlighted in the geopolitical outcome following the USN Submarine Escape and Rescue response to the ARA SAN JUAN incident in November 2017.

PHASE I: Develop a conceptual solution that defines the methods and identify the major components required to meet the requirements in the description. Feasibility will be determined by identifying the catalyst required and scientific calculations and modeling to support required contaminant reduction catalyst technologies. The Phase I Option, if exercised, will include refinement of the proposed solution to support Phase II prototype development and the initial design specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Based on the results of the Phase I and the Phase II Statement of Work (SOW), refine, as necessary, the design to build and deliver one prototype for test. Testing will be conducted via bench-test in a simulated environment comparable to the anticipated operational environment at NSWC Philadelphia.

PHASE III DUAL USE APPLICATIONS: Beyond the ability to provide atmospheric containment removal technology to support the Submarine Escape and Rescue program, this technology could also provide benefits to all confined space emergency applications. In additional to the USN and Department of Defense (DoD), PMS391 collaboration initiatives and established Memorandum of Agreements with non-DoD federal and state emergency management organizations – to include the Federal Emergency Management Agency (FEMA), Department of Labor Mine Safety and Health Administration (DoL-MSHA), National Institute of Occupational Safety and Health (NIOSH), and National Aviation and Space Administration(NASA) – can be leveraged to address similar technology needs and requirements. Upon successful prototype testing, the technology is anticipated to be transitioned via backfit installation onboard in-service submarines and implemented as part of new construction for the USS COLUMBIA class and the future SSN(X) class of submarines.


  1. "Central Atmosphere Monitoring System." U.S. Naval Research Laboratory. 28 November 2018.  
  2. "Vehicle Cabin Atmosphere Monitor." NASA. 11 April 2018. 28 November 2018.  
  3. “SSN 774 Class Guard Book, Disabled Submarine Survival Guide, FWD Escape Trunk (Lockout Trunk).” Naval Sea Systems Command, S9594-AP-SAR-G10, 0910-LP-018-5820, Revision 00, 27 April 2006; Change 1, ACN 2/B of 7 Feb 2019; Distribution Statement A: Approved for Public Release, Distribution is Unlimited.
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