A fire aboard a Navy ship can quickly become a deadly cauldron. Navy scientists are conducting research to ensure that sailors and their ships can be protected from the deadly effects of fire.
The Navy Technology Center for Safety & Survivability carries out research aimed to solve current and future Navy problems regarding fire and atmospheric hazards. Dr. Frederick Williams, director of the Center, explained, "The Center's mission is to assure that the sailors have the best tools possible to combat the ravages of shipboard fires."
The Center has unique fire research facilities that include pressurable chambers up to a 10,000-cubic-foot capacity at the Center's test site. The Center also has custody of the world's unique fire test ship, the ex-USS Shadwell (LSD-15), located in Mobile, Ala., where full-scale fire and damage control tests are conducted using the reality conformations of active duty sailors. Using the ex-USS Shadwell, Naval Research Laboratory (NRL) scientists are able to enhance their technology base for introducing advanced damage control concepts to the fleet.
Navy scientists and engineers are seeing success in several areas of fire fighting research, including the use of high expansion foam and halon alternatives. Scientists at NRL have successfully tested high expansion foam aboard the ex-USS Shadwell.
The Navy is interested in using high expansion foam to protect large volume, mission-critical spaces, such as hangar bays, well decks, vehicle stowage areas and magazines in future ships. High expansion foam can quickly fill a compartment and get water to fire threats in amounts sufficient to extinguish the fires, but substantially less than amounts typically delivered by deluge sprinkler water systems.
In the tests conducted aboard the ex-USS Shadwell, test engineers compared high flow rate aqueous film forming foam (AFFF) overhead deluge sprinklers and two high expansion foam systems against a triple threat fire (Class A, Class B pool and Class B running fuel fires). The high expansion foam systems included a fantype system using outside air to generate expanded foam, or an inside-air system using ceiling-mounted generators within the protected space.
Navy researchers found the high expansion foam to be the system of choice for fighting fires in those areas where there is a potential for multiple obstructed fire threats. The Navy is currently developing the ship-to-shore connector (SSC), which will replace the existing landing craft air cushion (LCAC). Fire protection for the SSC must be "halon-free," which requires identifying suitable fire fighting agents to replace the Halon 1301 and Halon 1211 systems, which currently protect the turbine engine enclosures, auxiliary power units, fuel bays, and the cargo deck on the LCAC. Also, since the SSC will be minimally manned and weight will be a critical factor, fire fighting agents and systems that offer low weight and low life cycle cost economies are essential.
NRL researchers recently completed successful tests to demonstrate the effectiveness of propelled extinguishing agent technology (PEAT) to protect the SSC turbine engine enclosures, auxiliary power units, and fuel bay compartments. The successes of this fire test series offer a more than 50 percent reduction in weight and maintenance-free fire protection option for the SSC program.
