As importaut as identifying promising firefighting agents is the design of efficient and effctive delivery systems for the agents, reccgnizing the complex geometry and guraticn of shipboards. Based on industry experience and Navy studies, there are no drop-in or near-drop-in substitutes for shipboard Halon systems that do not pose their own environmental and/or toxicity risks. Consequently, existing ships will be supported from the staegic reserve and new non-Halon agents and systems will be designed only for new-costruction vessels. Non-ODS HFC-227ea and fine-water mist have been qualified as near-term replacements (stating with LPD 17 and CVN 76), but work continues on optimizing delivery systems and investigating other fire protection technologies for potential shipboard application.
The use of ODS solvents was embedded in thousands of MILSPECs and industrial processes tbat support the Navy. The Navy relied on methyl chloroform, carbon tetrachloride, CFC-11. CFC-113, and other chlorinated compounds for a multitude of shipboard and shoreside applications. Altemative solvents (e.g. citrus/based) and/or processes (e.g. aqueous cleaning) havebeen identilied for virtually all of these applications. The most difficult application to address has been the cleaninig of critical shipboard oxygen systems (e.g., piping, diving gear, and welding equipment) where flammability and/or toxicity risks must be minimized. Because no suitable altemative for CFC-113 existed in this context, the Navy cordeveloped with the private sector a new and patented aqueous, inorganic, alkaline solution known as Navy Oxygen Cleaner (NOC). NAVSEA has replaced approximately one million pounds per year of CFC-113 with this environmentally benign product which is being widely adopted in the aerospace, diving, marine, and military sectors in the U.S. and abroad.
Solid Wastes
Navy ships generate substantial volumes of solid wastes while underway, including paper, cardboard, metal (steel and aluminum cans, scrap, etc.), glass (primarily bottles), plastics (food wraapping, packaging materials, etc.), textiles, wood and miscellaneous materials. Submarines generate proportionately much less trash because they remove as much packaging as possible on the pier during loadout and they are not resupplied while undelway. Solid wastes, especially those containing food residues, cannot be held onboard for more than a few days without significant space conflicts, safety risks (fire, damage control), and sanitation and odor problems.
A suite of solid weste processipg equipments was developped by the Navy under a very intensive RDT&E program to meet tight Congressional deadlines in the early-to-mid 1990s and Fleet installations are underway on frigates and larger ships. The plastics waste processor(PWP) shreds, heats, aud compresses all waste plastic materials and items into thin 21"-diameter disks that are sealed into Odor-Barrier Bags and held for return to port. The final Plastics Waste Processor backfit occurred in December 1998 and they are being forward fit into all new construction. The large pulper and small pulper grind paper, cardboard and food into a non-buoyant seawater slurry that is discharged overboard beyond 3 nm from shore. The metal/glass shredder tears and crushes metal and glass into biodegradable burlap bags that are discharged overboard beyond 12 nm from shore. All pulper and shredder backfits will be completed by the end of FYOO and they are also being forward fit into new ships.
The Navy-deeveloped solid waste processing equipment is considered an interirn solution until a more advanced aud complete shipboard disposal technology can be developed, although the "ultimate" answer may not be a backfit option. Thermal destruction is the most appropriate technology for Navy ships for: complying with stricter discharge restrictions; avoiding the shipboard storage of flammable, unsanitary, and odor-causing trash; minimizing reliance on shoreside support for waste offload and disposal; reducing the manpower associated with shipbord waste management; enhancing crew health, safety, and quality of life; and lowering Fleet TOC. The Navy has used very simple "MILSPEC" incinerators on aircraft carriers and amphibious ships for decades, but these are essentially reffaetory-lined fireboxes with no auxiliary fuel, no combustion control, no air emissions monitoring and abatement and no protection for sailors from the fire during feeding and stoking.
