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Under the Montreal Protocol, an international treaty, the production of the fire and explosion protection agent Halon 1301 (bromotrifluoromethane, BFC-13B1, CBrF(3)) was phased out in the United States at the end of 1993. No environmentally acceptable halon substitute that is equivalent to the existing halons in toxicity effectiveness, and dimensionality has been identified. The objective of the overall effort is to assess compounds containing members of the main group elements as fire extinguishants and has potential halon replacements.

Current commercially available Halon 1301 replacement compounds (other than CF3I) lack the fire suppression effectiveness of halon primarily because they do not contain bromine in their molecular structure. Bromine is thought to catalyze radical recombination reactions which deprive the combustion process of the (dot)OH and (dot)H radical species which promote the combustion of fuel molecules in the gas phase. This project was conceived to develop new fire suppressants incorporating bromine by basing the compounds on chemical families with expected or demonstrated short atmospheric lifetimes. These compounds are said to be tropodegradable bromocarbons. The targeted chemical families in order of importance were partially fluorinated alkenes, ethers, and amines. The alkenes have now been shown to have very short lifetimes on the order of days. This project identified several low boiling brominated and partially fluorinated alkenes, ethers, and amines with potential of meeting the toxicity, fire suppression, and environmental criteria currently identified under the EPA's SNAP program for halon replacements. Several of these tropodegradable compounds were subsequently acquired and their cup-burner flame suppression performance evaluated with promising results. Several of the bromofluoro alkenes have now also been evaluated in an acute inhalation toxicity test which yielded extremely promising results for this chemical family. This is an interim report covering the first phase of an ongoing effort.

Halon 1211 has been widely used throughout the United States Air Force (USAF) as a streaming agent to extinguish fires. Because it is a depleter of stratospheric ozone, however, its production has been halted. The USAF has been performing research to identify potential replacements. Most "first generation" candidates, those chemicals that were readily available and had significant toxicological information, are not as effective as Halon 1211, and many have environmental an toxicological drawbacks. Consequently, the USAF has initiated a search for advanced streaming agents. Technology review have identified promising chemical families. This report provides a description of the National Academy of Science (NAS) risk assessment paradigm and its use in assessing specific chemicals and families of chemicals identified as having potential to replace Halon 1211 for streaming applications.

This project is an investigation of advanced fire suppression agents as replacements for Halon 1211 used in U.S. Air Force flightline and aircraft portable fire extinguishers. Materials tested in this test series emphasized agent blends containing bromoalkanes. Baseline tests were run with Halon 1211. The testing took into account agent discharge patterns, flow rates, wind conditions and technique, and allowed comparison of agent effectiveness to that of Halon 1211. Blends of small amounts (up to 24 weight percent) of 1-bromopropane in a hydrofluoropolyether showed enhanced fire extinguishment performance over that of either of the pure components. Similar enhancement was seen with HFC-23fa and 1-bromopropane. Results were compared to those obtained in similar testing performed for the U.S. Army., Document contains color images.

The production of halon fire extinguishing agents, which are widely used throughout the Air Force, is banned in the U.S. by international agreement, and no environmentally acceptable replacement equivalent to existing halon in toxicity and effectiveness has been identified. It is desired to identify mechanisms by which extinguishants inhibit and extinguish fires to provide a basis for selection of new agents. This project investigated catalytic reactions that remove key species (such as hydrogen) from the flame, and compared and contrasted the roles of heat absorption and heterogeneous reactions in flame inhibition. Flame speed (an indicator of the degree of inhibition) was earlier proven to equate to the amount of heat removed from a burner. Equipment was designed and built to generate particles, to measure the heat extracted from a set of burners (named Sapphire) under atmospheric and subatmospheric conditions, and to identify species in the various regions of the flame. Halon's and other halogenated fire extinguishing agents, phosphorus-nitrogen compounds, and iron-containing compounds were tested. Correlations were made between the heat extracted and (1) the extinguishment of the flame and (2) the fuel/air ratio. A flame molecular beam/mass spectrometer (Sapphire 2) proved to be effective for studying inhibition chemistry. Inhibition by iron compounds was demonstrated, and recommendations for future work were made.

The primary objective of the Thermionic Systems Evaluation Test (TSET) Program was to obtain valid and sufficient information to fulfill the U.S. thermal vacuum and mechanical test requirements for space nuclear power systems. The TOPAZ-II Ya-21U System Test Plan, prepared jointly by Russian and U.S. specialists, was implemented to achieve this primary objective. A supporting objective, pursued in parallel, was to acquire valid and verifiable test results from the Russian TOPAZ-II system test program to supplement the objectives achieved during the U.S. test program.

In 1993, production of halon fire and explosion protection agents was phased out and to date, no Halon 1301 substitute has been identified to provide total flood protection against fires and explosions in normally occupied areas without major changes in system hardware. A study was begun to assess the probability of success and to determine the most promising directions for development of new chemical alternatives to Halon 1301. A database entitled the USAF/AAWG/CGET ADVANCED AGENT REFERENCE Database was established as a repository of summary information on documents relating to advanced agents. This report describes the structure and organization of the database, and provides images of the major forms used to present the data, which includes a complete bibliographic citation, abstract, and text blocks for conclusions on potential agent use and evaluation of the concept presented in the paper. The data are stored in a companion database, the NMERI LIBRARY Database.

The objective of the overall advanced agent program is to develop new, highly effective chemicals to replace Halon 1211 in military streaming applications. The portion of the work discussed in this document has, as an objective, an initial investigation of tropodegradable compounds as Halon 1211 replacements for streaming agents. This report documents the determination of cup-burner extinguishment values for selected compounds.

Halon 1211 has been widely used throughout the United States Air Force (USAF) as a streaming agent to extinguish fires. Because it is a depleter of stratospheric ozone, however, its production has been halted. The USAF has been performing research to identify potential replacements. Most 'first-generation' candidates, those chemicals that were readily available and had significant toxicological information, are not as effective as Halon 1211, and many have environmental and toxicological drawbacks. Consequently, the USAF has initiated a search for advanced streaming agents. Technology review have identified promising chemical families; however, many of these have insufficient toxicity information to allow a risk evaluation. Detailed toxicity testing is expensive and time-consuming. This document identifies promising methods for inexpensive screening and ranking of chemical families and chemicals within those families that have potential as Halon 1211 substitutes. These tests include acute toxicity or lethality; hepatoxicity; teratogenicity; cardiac sensitization; and genetic toxicity (mutagenicity). These methods cannot replace whole-animal testing as required by regulatory agencies, but can be used as a screening technique to reduce the cost of testing large numbers of chemicals. A second toxicity screening approach uses Quantitative Structure-Activity Relationship (QSAR) analyses.

In 1993, production of halon fire and explosion protection agents was phased and to date, no Halon 1301 substitute has been identified to provide total-flood protection against fires and explosions in normally occupied areas without major changes in system hardware. The objective of this study was to assess the probability of success and to determine the most promising directions for development of new chemical alternatives to Halon 1301. The Advanced Agent Working Group, a military/industry user's group, was formed and a research program initiated to review technology on fire and explosion suppression and chemical families; to select and analyze chemicals and chemical families for use as Halon 1301 replacements; to assess the potential of the identified chemicals; and to determine prospects for a Halon 1301 replacement. The most promising non-halocarbon compounds are the phosphorus compounds (particularly phosphorus nitrides), bromine-substituted silicon and siloxane compounds, and transition metal compounds. A number of these non-halocarbon materials are solids or high boiling point liquids; however, many of these appear to have sufficiently high vapor pressures that they could volatilize completely. Carriers such as hydrofluorocarbons (HFCs) and hydrofluoroethers (HFEs) may be necessary in some cases.

The objective of the overall effort is to develop new chemical compounds as Halon 1211 replacements. Four families of compounds are particularly promising-phosphorus nitrides, metal compounds, silicon compounds, and tropodegradable halocarbons. This report is Volume I of a 5-volume series of reports: Volume II covers metal compounds; Volume III, phosphorus compounds; Volume IV, tropodegradable halocarbons; and Volume V, laboratory-scale streaming tests. This document assesses silicon compounds as potential halon substitutes. Silicon compounds have lower atmospheric lifetimes than do the closely related carbon compounds. Thus, all other things being equal, Global Warming Potentials (GWP) and Ozone Depletion Potentials (ODP) are lower. To avoid toxicity and stability problems, it is essential that halogen atoms (fluorine, chlorine, bromine, and iodine) not be attached directly to the silicon atom. Such molecules are highly susceptible to hydrolysis with the formation of hydrogen halides. Moreover, the number of hydrogen atoms must be kept low to decrease flammability. With these targets in mind, an assessment of the properties and syntheses of silicon compounds was undertaken. Based on this assessment, a number of silanes and siloxanes containing bromocarbon substituents are recommended for further evaluation.

The objective of the overall effort is to develop new chemical compounds as Halon 1211 replacements. Four families of compounds are particularly promising-phosphorus nitrides, metal compounds, silicon compounds, and tropodegradable halocarbons. This report is Volume IV of a 5-volume series of reports. Volume I covers silicon compounds; Volume II, metal compounds; Volume III, phosphorus compounds; and Volume V, laboratory-scale streaming tests. This document assesses tropodegradable halocarbons as candidates as Halon 1211 substitutes.

The objective of the overall effort is to develop new chemical compounds as Halon 1211 replacements. Four families of compounds are particularly promising-phosphorus nitrides, metal compounds, silicon compounds, and tropodegradable halocarbons. This report is Volume II of a 5-volume series of reports. Volume I covers silicon compounds; Volume III, phosphorus compounds, Volume IV, tropodegradable halocarbons; and Volume V, laboratory-scale streaming tests. The portion of the work presented in this document reviews metal compounds as candidates as Halon 1211 substitutes and reports laboratory-scale testing of these compounds.

Fluoroiodocarbons (FIC) - highly effective, 'second-generation' agents -- have been identified as replacements for halons, the production of which ended on 31 December 1993. In an attempt to improve the toxicological characteristics of FICs, to decrease agent cost, and to possibly improve performance as a streaming agent in military applications, blends of FICs with other chemicals are being investigated. This report describes the initial results of the blending work with trifluoroiodomethane (CF3I), the most promising FIC fire suppressant. Toxicities, likely regulatory regulations, and availability indicate that only hydrofluorocarbons (HFC) can be considered at this time for blending with CF3I or other FICs. Seven HFCs (HFC-236fa, -227ea, -143a, -134a, -125,-23, and -4-3-10mee) were selected for initial investigation. Based on the toxicities of CF3I and the proposed blending agents, the final blends should contain 40 percent or less by volume CF3I in order for the cardiac sensitization No Observed Adverse Effect Level (NOAEL) value to be equal to that of Halon 1211. Cup-burner extinguishment concentrations at a 40 percent by volume CF3I concentration ranged from slightly higher to significantly lower than those for pure CF3I. Those agents identified as meeting the criteria for continuation in the program should be tested in laboratory- and field-scale streaming apparatuses.

As a result of stratospheric ozone depletion and greenhouse warming concerns, the present halon fire-extinguishing agents will be phased out by 1 January 1994 under an international treaty. The U.S. Air Force has placed a high priority on the development of substitute agents to replace halon fire suppressants. Through intensive literature review, database development, documentation, and predictive algorithm refinement, a prior phase of this program identified several agents that may have the potential to replace Halon 1211 for military use. These agents were subjected to extensive laboratory tests with the NMERI 5/8-scale cup burner being the primary testing device. New algorithms were developed for the estimation of selected properties. Testing results showed that bromine atoms provide the greatest chemical extinguishment, closely followed by iodine atoms. None of these agents, which are termed "first generation," has an effectiveness equal to that of the present halons. For this reason, it is essential that second-generation replacement agents, many of which are known to be clean, highly effective, and to have a low global environmental impact, be investigated. Work on first-generation replacement agents and alternatives should continue through medium-scale testing so that the U.S. Air Force has agents available in the near-term. jg p3, See also Volume 1, AD-A242 815.

The objective of this project was to assess the impact on the U.S. Air Force (USAF) of national and international restrictions on the production and use of chlorofluorocarbons (CFCs), halons, and other substances believed to contribute to stratospheric ozone depletion. The Montreal Protocol (a United Nations agreement) and the U.S. Clean Air Act Amendments of 1990 place restrictions on the production and use of CFCs and halons with eventual phaseout of production by the year 2000. CFCs are widely used as refrigerants, cleaning solvents, sterilants, foam-blowing agents, and aerosol propellants. Halons are used primarily as fire and explosion suppression agents. The USAF uses CFCs and halons extensively in a variety of ways, many of which are critical to combat operations and capabilities. This project provides an assessment of the technologies for replacements or alternatives to the CFCs and halons being phased out and the resultant impact on USAF mission capabilities. Recommendations are made for actions necessary to mitigate the impact of CFC and halon production and use restrictions.

This report summarizes the testing efforts on CF3I as a halon replacement agent; these efforts were supported by the CF3I Ad Hoc Working Group. The Working Group included representatives from the U.S. Air Force, Army, Navy, North Slope oil and gas producers, Pacific Scientific, and West Florida Ordnance. The testing efforts confined the laboratory-scale fire suppression and explosion inertion data, determined key acute toxicological information, assessed global environmental characteristics, identified manufacturing sources for developmental quantities of agent, and determined agent stability and materials compatibility properties. The n-heptane cup-burner concentration was 3.1 percent and the propane inertion concentration at peak flammability was 6.2 percent. The atmospheric lifetime is less than 1 day, the ODP is less than 0.008 and more likely 0.0001, and the 20-year GWP is less than 5 relative to CO2. Toxicological tests showed that CF3I has a low order of acute toxicity with the 15-minute rat LC50 equal to 27.4 percent. The dog cardiac sensitization NOAEL was 0.2 percent and the LOAEL was 0.4 percent. Since the expected design concentration will be in the range of 5 to 7 percent, the cardiotoxicity profile will preclude the use of CF3I for total-flooding applications in normally occupied areas. However, CF3I is still a highly promising replacement for unoccupied areas and streaming applications.

This report addresses the fire suppression mechanism survey and candidate survey for advanced streaming agents. These surveys led to the identification of chemical families from which an initial list or Broad List of Candidates was developed. The Broad List was comprised of specific chemicals, which were selected by identifying the simplest "parent" molecule within each of the chemical families and making variations of the parent to incorporate desirable features that increase flame suppression capabilities and reduce atmospheric lifetimes. Information on the Broad List was collected focusing on physical/chemical properties, toxicity, manufacturability, environmental issues, and other relevant information. The chemical families identified include brominated alkenes, aromatics, ketones, aldehydes, esters, carboxylic acids, alcohols, ethers, amines, amides, morpholines, and silicon compounds as well as fluoroiodocarbons, metallics, sulfur and sulfur nitrogen compounds, phosphonitriles, epoxides, and nitrosyl compounds. Representative chemicals from each family will be tested for fire suppression capabilities.

The objective of the Combined Norwegian/U.S. Aircraft Shelter Quantity-Distance Program was to establish an experimental database that could be used to develop explosives safety criteria for a Norwegian-designed aircraft shelter. These shelters have been constructed at various bases in Europe and are used by U.S. and Norwegian air forces. The current criteria for explosives storage in aircraft shelters are based largely on U.S. aircraft shelter designs, which differ significantly in structural details from the Norwegian version. The program included four tests of 1/3-scale models of the Norwegian shelter. Charges varying from 3.7 to 100 kg of C-4 explosive were detonated inside the model shelters. Airblast pressures were measured in the interior and exterior areas surrounding the models. High-speed photography and accelerometers were used to determine structural debris trajectories and velocities. The final distribution of structural debris in the areas surrounding the models was also recorded. Volume I of this report presents a detailed discussion of the results of each test with selected experimental data. Volumes II through V provide a complete set of the experimental data gathered in each of the test events. These data will be provided to those U.S., Norwegian, and NATO agencies responsible for establishing explosives storage safety criteria for the Norwegian aircraft shelter., See also Volume 3, AD-A271 432.

The objective of the Combined Norwegian/U.S. Aircraft Shelter Quantity-Distance Program was to establish an experimental database that could be used to develop explosives safety criteria for a Norwegian-designed aircraft shelter. These shelters have been constructed at various bases in Europe and are used by U.S. and Norwegian air forces. The current criteria for explosives storage in aircraft shelters are based largely on U.S. aircraft shelter designs, which differ significantly in structural details from the Norwegian version. The program included four tests of 1/3-scale models of the Norwegian shelter. Charges varying from 3.7 to 100 kg of C-4 explosive were detonated inside the model shelters. Airblast pressures were measured in the interior and exterior areas surrounding the models. High-speed photography and accelerometers were used to determine structural debris trajectories and velocities. The final distribution of structural debris in the areas surrounding the models was also recorded. Volume I of this report presents a detailed discussion of the results of each test with selected experimental data. Volumes II through V provide a complete set of the experimental data gathered in each of the test events. These data will be provided to those U.S., Norwegian, and NATO agencies responsible for establishing explosives storage safety criteria for the Norwegian aircraft shelter., See also Volume 1, AD-A271 430.

The objective of the Combined Norwegian/U.S. Aircraft Shelter Quantity-Distance Program was to establish an experimental database that could be used to develop explosives safety criteria for a Norwegian-designed aircraft shelter. These shelters have been constructed at various bases in Europe and are used by U.S. and Norwegian air forces. The current criteria for explosives storage in aircraft shelters are based largely on U.S. aircraft shelter designs, which differ significantly in structural details from the Norwegian version. The program included four tests of 1/3-scale models of the Norwegian shelter. Charges varying from 3.7 to 100 kg of C-4 explosive were detonated inside the model shelters. Airblast pressures were measured in the interior and exterior areas surrounding the models. High-speed photography and accelerometers were used to determine structural debris trajectories and velocities. The final distribution of structural debris in the areas surrounding the models was also recorded. Volume I of this report presents a detailed discussion of the results of each test with selected experimental data. Volumes II through V provide a complete set of the experimental data gathered in each of the test events. These data will be provided to those U.S., Norwegian, and NATO agencies responsible for establishing explosives storage safety criteria for the Norwegian aircraft shelter., See also Volume 4, AD-A271 433.

The objective of the Combined Norwegian/U.S. Aircraft Shelter Quantity-Distance Program was to establish an experimental database that could be used to develop explosives safety criteria for a Norwegian-designed aircraft shelter. These shelters have been constructed at various bases in Europe and are used by U.S. and Norwegian air forces. The current criteria for explosives storage in aircraft shelters are based largely on U.S. aircraft shelter designs, which differ significantly in structural details from the Norwegian version. The program included four tests of 1/3-scale models of the Norwegian shelter. Charges varying from 3.7 to 100 kg of C-4 explosive were detonated inside the model shelters. Airblast pressures were measured in the interior and exterior areas surrounding the models. High-speed photography and accelerometers were used to determine structural debris trajectories and velocities. The final distribution of structural debris in the areas surrounding the models was also recorded. Volume I of this report presents a detailed discussion of the results of each test with selected experimental data. Volumes II through V provide a complete set of the experimental data gathered in each of the test events. These data will be provided to those U.S., Norwegian, and NATO agencies responsible for establishing explosives storage safety criteria for the Norwegian aircraft shelter., See also Volume 5, AD-A271 434.

The objective of the Combined Norwegian/U.S. Aircraft Shelter Quantity-Distance Program was to establish an experimental database that could be used to develop explosives safety criteria for a Norwegian-designed aircraft shelter. These shelters have been constructed at various bases in Europe and are used by U.S. and Norwegian air forces. The current criteria for explosives storage in aircraft shelters are based largely on U.S. aircraft shelter designs, which differ significantly in structural details from the Norwegian version. The program included four tests of 1/3-scale models of the Norwegian shelter. Charges varying from 3.7 to 100 kg of C-4 explosive were detonated inside the model shelters. Airblast pressures were measured in the interior and exterior areas surrounding the models. High-speed photography and accelerometers were used to determine structural debris trajectories and velocities. The final distribution of structural debris in the areas surrounding the models was also recorded. Volume I of this report presents a detailed discussion of the results of each test with selected experimental data. Volumes II through V provide a complete set of the experimental data gathered in each of the test events. These data will be provided to those U.S., Norwegian, and NATO agencies responsible for establishing explosives storage safety criteria for the Norwegian aircraft shelter., See also Volume 2, AD-A271 431.

As a result of stratospheric ozone depletion and greenhouse warming concerns, the present halon fire-extinguishing agents will be phased out by 1 January 1994 under an international treaty. The U.S. Air Force has placed a high priority on the development of substitute agents to replace halon fire suppressants. This report describes the laboratory-scale experimental work performed on the Halon 1301 replacement agents. The 5/8-scale NMERI cup burner was used extensively throughout this program. A new laboratory total-flood test apparatus the Laboratory Extinguishment and Emissions Test Chamber (LEETC)-has been constructed to allow both determination of extinguishment concentrations under a total-flood scenario and to measure emissions. Emissions were determined using the Fourier transform infrared (FTIR) spectrometer. The LEETC provided extremely valuable information on both extinguishment and on agent decomposition products under total-flood conditions. The cup-burner results showed that no first-generation agent (hydrochlorofluorocarbon, hydrofluorocarbon, or perfluorocarbon) will provide extinguishment equivalent to that obtained with the present halons. It is recommended that investigations of second-generation Halon 1301 replacement agents be initiated. These agents contain bromine and/or iodine, but have low ozone-depletion potentials and low atmospheric lifetimes because of tropospheric degradation. Further work to develop refined equipment, techniques, and test protocols is also recommended. jg, See also Volume 1, AD-A242 815.

The objectives of this project were to develop conceptual designs for a long-range, fire suppressant delivery system and to construct, test, and demonstrate a prototype unit. Two basic long-range delivery system concepts were considered: streaming and catapulting. Design considerations were throw range, effect of winds, accuracy of delivery, and mass of agent delivered to the target. Streaming concepts were investigated initially, but were abandoned because the desired delivery range could not be achieved. Catapulting concepts became the focus of the remainder of the project. The first catapulting prototype device demonstrated in field testing that a 35-pound sphere filled with firefighting agent could be delivered a distance of 600 feet with a reasonable accuracy. JP-4 pool fires of 40 ft2 and 80 ft2 were extinguished in testing from a distance of 600 feet and 400 feet, respectively. This led to the development of a more advanced, computer-controlled, rapid-fire prototype. Field testing of the second prototype demonstrated the capability to deliver 6-shot barrages of 35-pound agent canisters to a distance of over 1400 feet.... Launcher, Catapulting, Firefighting cannon, Firefighting projectiles, Firefighting prototype, Fighting hazardous fires.

The objective of this project was to identify USAF airbase facility/ utility energy needs over the next 30 years, to evaluate new energy technologies that might be used to help meet these needs, and to recommend R and D efforts that could assist in this process. The existing and projected world energy situation was reviewed, data on USAF airbase energy consumption and costs were analyzed, and new USAF systems and projected force structures were examined as to influences on airbase energy consumption. Baselines of current and projected energy consumption and associated costs were established. Twenty-three (23) new energy technologies were reviewed, and 15 were identified as having potential benefits for USAF airbases. Recommendations for R and D to assist this process are provided.

This effort evaluated medium-scale candidate halon alternatives for use instead of Halon 1211 in firefighter training scenarios. Candidate agents tested included neat HCFC-123, neat HCFC-22, and selected blends containing two components from the set of HCFC-22, -123, -141b, - 142b, and - 152a. Agents were tested progressively on JP-4 fuel fires of 4, 32, and 75 sq ft. Effectiveness was evaluated by measuring quantities and times required for extinguishment. Both neat HCFC- 123 and a blend of HCFC- 123 and - 142b (80:20 by moles) appear attractive as alternative training agents, because their extinguishing behavior simulates that of Halon 1211, and they appear to have acceptable toxicities for outside use with protective gear. On 4-sq ft fires the critical application rates of these two alternative agents are virtually identical to that of Halon 1211; on larger fires the critical application rates are 1.7 to 3 times that of Halon 1211. Plots of fire size versus quantities of agents required for extinguishment gave smooth curves and allowed estimation of the quantities of agents required to extinguish fires of various surface areas. It is recommended that both neat HCFC-123 and a blend of HCFC-123 and -142b (80:20) be tested on 150-sq ft pool fires and 75-sq ft three-dimensional fires in Phase IV of this effort.... Halon, Alternative, Blends, Fire, Training, Extinguishment, JP-4, HCFC.

The overall purpose of this effort was to evaluate candidate low, ozone-depleting halon alternatives for use instead of Halon 1211 in firefighter training. This Phase IV effort used both 150-ft squared JP-4 pool fires and 75- ft squared three-dimensional running fuel fires. Two types of 3-D running fuel apparatuses were built; these simulated a suspended jet engine leaking fuel onto a runway. Standard 150-pound Halon 1211 extinguishers were filled with Halon 1211 or neat HCFC-123 or blends of HCFC-123 with either HCFC-22 or - 142b. Both neat HCFC-123 and a blend of HCFC-123 and - 142b (80:20 by moles) simulated Halon 1211 effectively. These agents were designated OPE- 1 and OPE-2, respectively, standing for Ozone Protective Extinguishants numbers 1 and 2. A nozzle change was required for effective extinguishment and simulation of Halon 1211. OPE-2 is 20 percent less toxic than OPE-1, but is slightly less effective and requires 20 percent more agent, cancelling the toxicity advantage. The logistics of handling a neat agent would be simpler than the handling of a blend. It is recommended that either OPE-1 or OPE-2 with a nozzle change be used for firefighter training. Use of either agent will allow continued training of firefighters while cutting ozone depletion by over 99 percent. Draft military specifications for both agents are included.... Fire, Training, Halon, Alternative, Three-dimensional, HCFC-123, HCFC-142b.

The objective of this overall project is to develop one or more alternative clean halocarbon fire extinguishing streaming agents to replace Halon 1211. In this effort a technology review was conducted and an experimental plan was prepared. Screening criteria are presented with discussions and approaches to meeting the following criteria: cleanliness, toxicity, fire suppression, ozone depletion potentials (ODPs), global warming potentials (GWPs) , physical properties, availability/manufacturability, cost, materials compatibility, and chemical stability. Lists of near-, medium-, and far-term candidate agents are presented. An algorithm was developed that enables prediction of atmospheric lifetimes of hydrogen-containing one-and two-carbon haloalkanes containing fluorine and/or chlorine. Relationships are examined among C-H bond strength, activation energy for hydrogen abstraction by OH, reaction rate constants, tropospheric lifetimes, and ODPs. A review of existing and emerging technologies for the destruction of halocarbons is included.

The overall objective of this effort was to determine the potential roles of van der Waals complexes of dioxygen, hydrocarbon fuel, and halon molecules in combustion and extinguishment. This study provides insights into the reactions between the fire extinguishant CF3Br and the dominant flame free radicals H, O, and OH. Molecular complexes of halon/dioxygen, halon/hydrocarbon, and hydrocarbon/dioxygen were generated by expansion of gas mixtures through a supersonic nozzle. These complexes then underwent dissociative photoionization followed by mass spectrometric analysis. Photoion yield curves were analyzed to characterize fragmentation processes and energy states. Thermodynamic properties of the clusters and fragments were measured. No evidence of interaction Of CF3Br with H atoms was found. Studies of frozen collision complexes offer a powerful method for elucidating the initial steps of reaction chemistry. Small heteroclusters were prepared, relative number densities of neutrals were determined, kinetic energy distributions of fragment ions were measured, and the first reported analysis of clusters in a ternary molecular beam was carried out. The results of these experiments have many potentially significant implications for development of alternative fire suppression agents.... Complexes, Clusters, Halon, Fuel, Oxygen, Radical, Mechanism, Extinguishment.

The objective of this effort was to develop an experimental approach for identification and characterization of the first reactions occurring when halon fire extinguishing agents enter flames. This report reviews technologies available for measurement of flame temperatures and concentrations of chemical species in flames. Methods reviewed for measurement of flame temperatures include use of thermocouples, laser Raman and coherent Anti Stokes Raman (CARS) spectroscopy, and silicon carbide filaments with optical monitoring. Methods assessed for applicability to measurement of concentrations of chemical species in flames include laser Raman spectroscopy, isolation of fragments and products on a frozen argon matrix followed by analysis by Fourier-transform infrared spectroscopy, and photoionization followed by mass spectrometry. An experimental approach for studying reactions of halons in flames is developed. This approach consists of four elements: (1) construction of an information database, (2) an investigation of the relative importance of physical and chemical processes in halon fire extinguishment, (3) development of flame extinguishment diagnostics and characterization, and (4) time-dependent studies of free-radical reactions.

This project was established to originate concepts for next- generation fire extinguishing agents. In Phase II, laboratory tests and scoping trials were performed to initiate a program for replacement of halon fire extinguishants in Air Force fire protection and firefighter training. Facilities were also established to perform laser Raman spectroscopic investigations of flame suppression halon agents, and initial, baseline Raman studies were carried out. Keywords: Halon, CFC, Chlorofluorocarbon, Ozone fire extinguishment, Flame suppression, Laser Raman spectroscopy.

Nonlinear structural problems in which material softening is present constitute a severe challenge to solution algorithms. Most of the existing computational codes are based on using an incremental procedure with iterations and suitable constraints. Among the types of constraints are load control, direct or indirect displacement control, and arc-length control involving a combination of load and displacement parameters. For many problems in which softening and localization occur, these algorithms fail at some point in the post-peak regime. In an attempt to remedy this problem, an alternative constraint condition is proposed whereby a combination of the total strain components is prescribed at the most critical point in the body. The critical point is defined to be that point where a suitable measure of strain is a maximum. Numerical solutions for both plane strain and plane stress problems are given to illustrate the ability of the procedure to capture post-peak responses of structures governed by materially nonlinear behavior.

Standard specifications for mounting the Hardened Aircraft Shelter Fire Protection System (HAS-FPS) are not sufficient because of the wartime threat to the facilities. Therefore, representative sections of the HAS-FPS, previously tested against actual fire threats, were installed in a full-scale HAS and tested against the blast threats. Data collected with accelerometers and strain gages on equipment were used with wall measurements to analyze the response of various mount concepts. Shock spectra and raw data were formulated into specifications that can be used in the performance specifications for HAS- FPS and other equipment of similar capacities and locations.

This project was established to originate concepts for next- generation fire extinguishing agents. In Phase III, an effort to develop a substitute agent to replace Halon 1211 in Air Force firefighter training was initiated. Laboratory-scale investigations of flame extinguishment by chlorofluorcarbons (CFCs) and hydrochlorofluorocarbons (HCSCs) were performed. Laboratory studies of physical properties of CFC blends were also carried out., See also Phase 2, AD-A227 347.

The system of Halon 1301 (CF3Br) and molecular oxygen (O2) was carefully studied. Small, isolated molecular clusters of Halon 1301 and the oxygen-atoms, flame free radical precursor O2 were formed in a supersonic molecular beam, and chemical reactions were initiated within the clusters by dissociative photoionization. The fragments formed were identified by mass spectrometry, and the ionization and appearance potentials for many of the species in this binary system were determined. The most striking result is the inability to detect oxygenated fragments of dissociative photoionization of the complex CF3Br.O2. The results hold important mechanistic implications for the role of CF3Br in fire extinguishment and in guiding the search for alternative firefighting agents.

The Air Force has an extensive inventory of Halon fire extinguishers, all of which require service and maintenance. When these operations are performed, halon is vented to the atmosphere, resulting in an estimated loss of up to 250,000 pounds of halon per year at a value approaching $500,000. Additionally, these emissions have a significant impact on stratospheric ozone. This project developed a recharge/recovery system for Halon 1211 to move the agent between vessels without venting, and to simultaneously determine the quality of the halon and remove contaminants. The project was accomplished in two phases. Phase I included a review of the commercial market and a summarization of available components. Phase II involved design, assembly, and testing. Over 200 transfer and recovery tests were performed on the prototype unit. The results of this effort are a prototype recharge/recovery unit for Halon 1211, operation and maintenance procedures, and a purchase description for use by the Air Force in procurement activities.

The objective of this project was to identify commercially available equipment and services for recovery of chlorofluorocarbons (CFCS) halons, and related alternative materials. Characteristics of available equipment have been collected and put into tabular form for ease of comparison. Capabilities and specifications for the equipment included in this study have been reported as received from the manufacturers. Concerns and issues related to the recovery/recycling/reclamation (R/R/R) of halocarbons were also identified and discussed.

The objective of this effort is to evaluate an experimental approach and initiate work to determine the initial chemical reactions occurring when halon firefighting agents extinguish flames. Initial studies using these procedures were also performed. Three techniques were studied to compare their usefulness for determining the concentrations of chemical species in flames: laser Raman spectroscopy, matrix isolation Fourier-transform infrared spectroscopy, and photoionization mass spectrometry. Laser Raman spectroscopy of hydrogen/oxygen flames extinguished with Halon 1301 provided identification of the principal flames species; however, this method was not effective in detecting minor species present in low concentration. The Raman spectrum of the hydrogen molecule was used to calculate flame temperatures. Matrix isolation experiments were used to characterize the fragmentation patterns of Halons 1211, 2402, and 1301. Of the three techniques, photoionization mass spectrometry was the most promising method for characterizing reactions occurring in flames. It was found that Halon 1211 does react with the free radical H, but the cross section of the overall process is small. No evidence was found for reactions between 0 atoms and either Halon 1211 or 1301. A database of fire suspension literature was developed and incorporated into the nmeri halocarbon data base.

The acute toxicity of Halon 2402 was assessed and compared to that of Halon 1211. The purpose of this effort was to determine the acute toxicity of Halon 2402 in laboratory animals and to compare this toxicity to that of Halon 1211. Because of the interest in Halon 2402 as a potential firefighting agent, it was necessary to evaluate the toxicity of this agent and compare it to that of Halon 1211, the standard USAF agent. Therefore, the New Mexico Engineering Research Institute (NMERI), in collaboration with the University of New Mexico College of Pharmacy, evaluated the acute toxicity of Halons 1211 and 2402 in rats. Because of the high vapor pressure of halons, the route of exposure posing the highest risk is inhalation. Therefore, determining the toxic effects of acute inhalation provides an important step in understanding the health risks of the agent.

A recent Air Force study resulted in the development of a fire detection and suppression system for tactical hardened aircraft shelters (HAS). This study recommended adjunct efforts be undertaken to assure that personnel within the HAS at the time of activation of the fire suppression system (Halon 1211) are provided the means of safe and rapid egress, and that an ancillary fuel securing system be provided within the HAS to secure fuel spills from ignition. This project provided the market surveys, comparative research, development, and physical testing which shall lead to procurement definition of both a personnel egress and fuel securing system. Many of the market surveys and much of the comparative research was performed via a subcontract to AMETEK, Offshore Research Engineering Division. Four smoke tests and one neat Halon 1211 discharge were used t test a wide variety of egress system combinations. The UL 162 wand and stovepipe tests were used to test the fuel-securing system. All testing was conducted at Tyndall AFB, Florida, and was considered highly successful in determining system performance. All survey, research and test results are contained in the report. The result of this effort is the final report which contains Military Purchase Descriptions for both the Personnel Egress System and the Fuel Securing System.

To keep personnel, aircraft, and munitions safe and ready, a fire protection system for hardened aircraft shelter (HAS) is needed. This report describes the effort to design, integrate, and test a fire protection system to combat fires in HAS, aircraft and associated equipment during hot fueling, defueling and other operations in semihardened aircraft shelters. The smart and fast detection/suppression system used was required to possess the capability to distinguish between normal operations/events, false stimuli and an actual fire. Halon agents were used for partial flooding tests. Agent toxicity and cleanliness were evaluated and considered in the selection of agents and systems. This report describes the five-part approach used to develop a fire detection system for HAS: 1. Define the HAS environment, 2. Analyze the HAS environment to determine the most likely fire scenarios, 3. Conduct thorough tests and evaluations of commercially available fire detectors, 4. Design, implement and evaluate HAS fire protection system tests, and 5. From the system analyses and tests, develop a purchase description. Keywords: Fire extinguishing agents, Fire detection, Fire suppression, JP-4 fuel, Halon.

This report documents the development of preliminary material properties for slurry infiltrated fiber concrete (SIFCON) using fine-grained sands. Included in the report are the test procedures., test results, SIFCON material costs and conclusion. Keywords: SIFCON; Sand slurries; Fluidity; Infiltration; Compressive strength; Specimens; Steel fiber.

The objective of this subtask was the development of flexural material properties for slurry infiltrated fiber concrete (SIFCON). Included in this report are the procedures used, the material properties data base, all test results, relationship plots, and general conclusions. Methods for testing SIFCON in shear and tension were also investigated. Slurry Infiltrated Fiber CONcrete, designated SIFCON, is a new composite material utilizing steel fibers in a cement-based matrix. It differs from conventional fiber-reinforced concrete in which the steel fibers are added to a typical concrete mix in a ratio of 0.5 to 1.5 percent by volume. SIFCON, on the other hand, starts with a bed of preplaced steel fibers in the range of 5 to 22 percent by volume. The fiber bed is then infiltrated with a low-viscosity cementitious slurry. The resulting composite material possesses very high strength as well as ductility. In addition it has been demonstrated that SIFCON is highly resistant to dynamic loads such as blast pressure and ballistic penetration.

In 1983 a new material, slurry-infiltrated fiber concrete (SIFCON), was brought to the attention of the Air Force Weapons Laboratory (AFWL) by Dr David Lankard of the Lankard Materials Laboratory (LML) in Columbus, Ohio. A review of both high strength as well as ductility. These properties indicated that the material had a potential use in a superhard silo structure. Because the material showed such promise, AFWL proposed a program to construct and test a scale model of a generic superhard silo structure using the SIFCON material. AFWL decided to place the structure in a scheduled calibration test that was part of the Intercontinental Ballistic Missile Silo Superhardening Technology (ISST) testing program in Yuma, Arizona. NMERI then began a program to develop a slurry mix design for use in the structure, as well as construction techniques for placing the SIFCON in the wall of the model. Keywords: Missile silo, Fiber concrete, Hardened structures, blast effects.

Firefighting resources, including consumables and vehicles, assigned to airbase fire departments in Europe and the Pacific are dispersed according to a predetermined plan before attack. Dispersal locations depend on availability of space in aircraft shelters and other protected areas designed and constructed for the protection of other resources; therefore, fire departments must compete for protected space. When an attack occurs, space may not be available or what is available may not satisfy the needs of the fire departments. A series of concepts was considered for possible use as splinter protection for the firefighting resources. These concepts were evaluated and two designs were developed to protect the resources to minimize damage from an attack. Two selected concepts were both earth-bermed structures. One structure was constructed from a corrugated steel culvert structure with a concrete floor and the other consisted of a reinforced concrete steel culvert structure with a concrete floor and the other consisted of reinforced concrete (shotcrete) arch. A suggested test plan is included for field testing the selected structure to verify the hardness of the prototype structure and address the constructibility of the concept. Keywords: Splinter Protection, Protective Construction, Hardened Construction, Shotcrete, Corrugated Steel Pipe, Conventional Weapons.

This report summarizes research involving the determination of parameters causing water damage to asphalt concrete. The study was a cooperative effort between the Federal Highway Administration (FHWA) and NMERI. Bituminous mixtures with a history of water susceptibility were fabricated by FHWA. Compacted mixtures were evaluated for moisture damage at FHWA, then shipped to NMERI for chemical analysis of the binders. Extracted binders were analyzed by a modified Clay-Gel procedure and infrared spectroscopy to determine whether differences between moisture conditioned and control asphalts could be measured. An Index of Relative Severity (water damage) has been defined from analysis of the data. Changes in certain asphalt chemical constituents may relate to retained strength for mixtures without antistripping additives. Potential moisture damage is predicted equally with a least two mechanical tests used for mixtures antistripping compounds. Keywords: Clay-Gel compositional analysis, asphaltenes, saturates, aromatics, polars, asphalt generic composition, asphalt functional group concentrations, ketones, sulfoxides, carboxylic acids, IR spectroscopy, Lottman procedure, Immersion-Compression, percent retained strength, antistripping additives or agents, moisture-damage severity, and degree of relative severity.

The objective of this effort was to determine an effective means to dispose of fuel cell polyurethane foam. The foam fills the fuel cells of certain Air Force aircraft to suppress explosions, attenuate fuel sloshing, and serve as a barrier to foreign object debris. Waste foam is generated by two processes. Foam contaminated with fuel and purge fluid is removed from fuel cells for periodic replacement. Scrap foam is left over when foam is cut to fit the interior of fuel cells. The traditional method of foam disposal is to bury it in a landfill. Foam is not very amenable to landfilling due to its high void ratio (greater than 95 percent voids). This study proceeded in three phases. The first phase was to determine if waste foam is a hazardous waste. In Phase II, we performed a comprehensive literature review to identify possible disposal methods, and tested the most promising methods in the laboratory. Finally, we performed a full-scale test of the best disposal method. (Keywords: Waste Disposal, Solid Waste, Wastes (Industrial), Incinerators, Hazardous Material, Foam, Plastic, Polyurethane, Polyester Plastics, Polyethers, Aircraft, Military Aircraft, Fuel Tanks, Fuel Cells, Air Operations, Air Force Logistics Command.

This report documents the investigation of asphalt-rubber mixtures for use as stress-absorbing membrane interlayers (SAMIs) for airfield pavements. The project was initiated in 1977 as a state-of-the-art review (Reference 1). That study concluded that use of SAMIs was promising for improving the performance of asphalt-concrete overlays on airfield pavements. A following study addressed material characterization and development of a proposed construction specification (Reference 2). This report covers follow-on monitoring of the performance of an experimental pavement project at Kirtland AFB, Apron A; construction and performance monitoring of two trial sections located at Williams AFB and Coolidge Field in Arizona; and the design and construction of a field experiment at Peterson AFB, Colorado. Based on the results obtained to date, the performance observed cannot be related in a meaningful way to the material characteristics. This results from the small time elapsed since construction of the pavements under observation. Based on experience, a revised proposed construction specification is included in the current report. Continued performance monitoring is recommended in order to obtain the benefit from the investment made in the initial construction documentation. Keywords: Airfield parameters, Asphalt rubber, Performance monitoring, Field observations, Reflection cracking.

A simple problem involving the identification of an explosive source as being unbermed or bermed using a pattern recognition based analysis of buried ground accelerometer measurements is presented. This problem illustrates the advantages of computerized information extraction from the measured waveforms. Information was extracted from the frequency and cepstrum descriptions of the waveforms in addition to the more traditional time domain information. These signal features were incorporated into a Fisher's Linear Discriminant pattern recognition procedure. Previously unseen signals were classified with up to 100% accuracy depending on which features were used. Close in explosive source measurements present unique problems to a pattern recognition based analysis approach. These problems are reviewed and approaches illustrated.