CHDS State/Local / ments is evaluated, smart practices are identified and reviewed, and a new model firefighter candidate screening policy supported and driven by a formal strategic plan is proposed. / Fire Chief, Concord; New Hampshire Fire Department

Time-Difference-of-Arrival (TDOA) location estimation is central to an OFDM based Precision Personnel Locator system being developed at WPI. Here we describe a component of the effort towards characterizing the performance of such a system and verifying the functionality of hardware and software implementations. The performance degradations due to noise in the received signal and misalignments between transmitter and receiver clock and heterodyne frequencies are investigated. This investigation involves development of a MATLAB simulator for the entire system, experimental measures using a prototype implementation and linearized analytic analysis of specific subsystems. The three types of characterizations are compared, confirming agreement, and analytic results are used to demonstrate construction of a system engineering design tool.

Death of firefighters due to structural collapse has been on the rise for the past few years, and has not gone unnoticed by the research and firefighting branches of the industry. However, the modes for improving this situation by both are very different. While firefighters depend on experience for detection, research organizations have invested in developing new technology to detect signs of structural collapse. Thus far neither effort has led to any improvement in the current circumstances. In order to bridge this gap, members of the fire-safety community need to more thoroughly understand the reasons for structural collapse due to fire. Through research and analysis, a case study manual analyzing structural steel failures due to fire was developed. This manual contains analysis of the actual mode of failure for the cases chosen, as well as analysis of alternative situations for each case that may have led to different outcomes. The goal of this manual is to aid in the teaching and practice of structural steel collapse due to fire as a supplement to current knowledge.

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004. / Includes bibliographical references (leaves 73-76). / The recent trend of using fine water mist systems to replace the legacy HALON- 1301 fire suppression systems warrants further study into other applications of the water mist systems. Preliminary research and investigation indicates that fine mists (20-25 pm droplet size) may reduce peak overpressures of a shock wave traveling through a space. Such pressure reductions could be used to mitigate the destructive effects of a shock wave (initiated by an explosive device) traveling through a structure. Currently these blast mitigation effects have only been demonstrated in small-scale shock tube tests and computer simulations. Uncertainty exists as to the scalability of such a system. The intention of this research is to investigate the applicability of such a blast mitigation system for shipboard use. Study into the degree of mitigation necessary to make a system practical for shipboard installation was conducted. In addition, a theoretical study of the mechanisms of blast mitigation using water mists was completed. Preliminary design of a full-scale system was examined. / (cont.) Given the recent trend toward tumblehome hull forms in future Naval Combatant designs, there exists strong applicability of this system in the "dead" spaces created by the shaping of the tumblehome hull. Further work is needed in numerical modeling and laboratory testing of specific phases of the mitigation. The end goal is a feasible design of a blast mitigation system to be used in the outermost spaces of Naval Combatants to protect interior vital system spaces. / by Julie A. Kitchenka. / S.M. / Nav.E.

Thesis (Ph.D.)--University of Western Sydney, 2009. / A thesis presented to the University of Western Sydney, College of Arts, Centre for Cultural Research, in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliographies.

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: suppression; drop size; high flash point pool fire. Includes bibliographical references (p. 210-218).

Η παρούσα εργασία εισάγει τον αναγνώστη στο φαινόμενο των δασικών πυρκαγιών. Στο παραπάνω πλαίσιο, καθοριστικός παράγοντας για την άμεση κατάσβεση των δασικών πυρκαγιών είναι η σωστή χωροθέτηση των πυροσβεστικών οχημάτων. Η βέλτιστη χωροθέτηση στο υπάρχων πρόβλημα επιτυγχάνεται μέσω των μοντέλων κάλυψης. Εφαρμόζονται και συγκρίνονται τα αποτελέσματα με την υπάρχουσα κάλυψη που παρέχεται από την υφιστάμενη χωροθέτηση των περιπολιών από την Πυροσβεστική Υπηρεσία στο νομό Αχαΐας. / -

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Water flows required for fire protection (fire flows) from water distribution systems (WDS) in rural towns in the Western Cape Province, South Africa, were evaluated as part of this research project. The fire flow requirements specified in different South African guidelines, as well as a number of international standards, were compared. Various guidelines and codes used in South Africa, including the South African National Standards, specify fire flow requirements according to the risk category of the area concerned. Alternative methods of firefighting and new firefighting technologies that can reduce the reliance on potable water resources for firefighting were evaluated. The traditional method of designing a WDS to provide potable water for firefighting, commonly employed in South African municipal areas formed the focus of the study. The potential fire risk costs (potential costs of damages if a fire was to occur) should also be considered, in addition to the network construction costs, when designing a WDS, in order to determine the most economically feasible option. Data obtained from the fire departments of three municipalities in rural towns of the Western Cape, was analysed to determine the actual flow rates that were required to extinguish fires in these towns. The records considered covered approximately one year in each case and included a total of 564 fire incident reports suitable for this study. According to the data, a small fraction (11%) of the fires was extinguished using water from the WDS by connecting firefighting equipment directly to a fire hydrant. The majority of the fires were extinguished by means of water ejected from a firefighting vehicle. This method implies the use of water drawn from the potable network at a certain location; the water is shuttled by firefighting vehicles, from either the fire station or from a central abstraction point in the WDS. The location of the said abstraction point was found to have a notable impact on the WDS and this received attention in this study. The data showed that 99.8% of the flows required in rural towns were lower than the flows recommended for moderate risk areas in typical South African guidelines. Hydraulic modelling of a hypothetical WDS model was conducted to illustrate that the provision of fire flows according to commonly used South African fire flow standards leads to higher costs. The latter hypothetical case study illustrates that designing a network to provide fire flows according to the referred standards resulted in 15% higher costs, compared to designing a network that would have provided for the actual recorded fire flows according to the data set obtained from the selected rural towns compiled for this study. The hypothetical case study also showed that the cost for a WDS, where sufficient pressure is required at all hydrants during peak fire flows, is 2.4% higher than the cost for a distribution system where water is supplied via predetermined hydrants for refilling firefighting vehicles. A WDS with central, predetermined abstraction points for refilling firefighting vehicles offers a solution to providing fire flows in areas where the distribution systems may be inadequate. The revision of the current fire flow standards of South Africa would, therefore, be a logical next step along with the reassessment of methods used for supplying fire flows. / AFRIKAANSE OPSOMMING: Water vloei vir brandbestryding (brandvloei) uit waterverspreidingstelsels (WVS) in plattelandse dorpe in die Wes-Kaap, Suid Afrika, is as deel van hierdie navorsingsprojek geëvalueer. Die brandvloei soos gespesifiseer in verskillende Suid-Afrikaanse riglyne, asook ʼn aantal internasionale standaarde is vergelyk. Verskeie riglyne en kodes wat in Suid-Afrika gebruik word, insluitende die Suid-Afrikaanse Nasionale Standaarde, spesifiseer brandvloei-vereistes op grond van die risiko-kategorie van ʼn spesifieke gebied. ʼn Verskeidenheid alternatiewe metodes vir brandbestryding en nuwe brandbestrydings-tegnologieë is ondersoek, om sodoende die afhanklikheid van ons beperkte drinkbare waterbronne vir brandbestryding te verminder. Die tradisionele metode om water aan munisipale areas te voorsien, die gebruik van ʼn WVS, is ook geassesseer. Hierdie metodes dui daarop dat die potensiële brandgevaar-kostes (potensiële koste van skade indien ʼn brand sou plaas vind) ook in ag geneem moet word, tesame met die konstruksie kostes van ʼn WVS, om sodoende die mees ekonomies haalbare netwerk te bepaal. Data wat verkry is vanaf die brandweer departement van drie plattelandse munisipaliteite in die Wes-Kaap is ontleed om die werklike vloei-tempos vas te stel wat nodig was om brande te blus in hierdie dorpe. Die data is verkry vir ʼn tydperk van een jaar en 564 brandverslae was bruikbaar vir die doeleindes van hierdie studie. Volgens die data was ʼn lae aantal (11%) van die brande geblus vanuit die WVS deur die koppeling van brandbestrydingstoerusting direk aan ʼn brandkraan. Die meeste van die brande is geblus met behulp van water wat voorsien is deur ʼn brandbestrydingsvoertuig. Met hierdie metode word water deur die brandbestrydings-voertuie aangery vanaf die brandweerstasie of onttrek vanuit ʼn sentrale ontrekkingspunt in die WVS. Daar is gevind dat die ligging van laasgenoemde ontrekkingspunt ʼn beduidende impak op die WVS het – hierdie aspek is daarom verder ondersoek. Die data het getoon dat 99.8% van die vloei-tempo’s wat nodig is om brande te blus in plattelandse dorpe, laer is as die brandvloei riglyne vir matige risiko-areas volgens tipes Suid-Afrikaanse standaarde. Hidrouliese modellering van ʼn hipotetiese WVS is uitgevoer om te illustreer dat die verskaffing van brandvloei volgens die standaarde wat algemeen gebruik word, hoër kostes tot gevolg het. Die laasgenoemde hipotetiese gevallestudie illustreer dat ʼn netwerk ontwerp om brandvloei te verskaf volgens die huidige standaarde 15% duurder is as vir netwerke wat ontwerp is om die werklike aangetekende brandvloei te voorsien soos getoon deur die veld-data wat vir hierdie studie verkry is. Die hipotetiese gevallestudie het ook getoon dat die koste vir ʼn WVS, waar voldoende drukke gehandhaaf moet word by alle brandkrane terwyl piek brand vloeie voorsien word, 2.4% duurder is as vir ʼn WVS waar die brandvloei verskaf word by voorafbepaalde brandkrane vir die hervulling van brandbestrydingsvoertuie. ʼn WVS met sentrale onttrekkingspunte vir die hervulling van brandbestrydingsvoertuie, bied ʼn metode om brandvloei te voorsien in gebiede waar die WVS onvoldoende is, bv. informele nedersettings. Die hersiening van die huidige brandvloei standaarde van Suid Afrika sou dus ʼn logiese volgende stap wees, tesame met die herevaluering van die metodes wat gebruik word vir die verskaffing van brandvloei.

"The primary purpose of this research was to quantify fire suppression and fire intensification phenomena for water spray application to high flash point hydrocarbon oil pool fires. Test data and analyses of the phenomena include the drop size distribution and application and delivered densities of various water sprays, and spray-induced oil cooling and oil splattering for mineral seal oil and for cooking oil 30-cm diameter pool fires. Four different types of tests were conducted as described below. A Dantec Particle Dynamic, phase Doppler, Analyzer was used to measure the water drop sizes and velocities generated by 13 selected nozzles and sprinkler heads. Most measurements were made 0.91 m (3 ft) below the nozzles/sprinklers, since this was the location of the center of the hydrocarbon pool in later fire tests. The correlations for the volume-median drop diameter, dw, were of the form , where D is the nozzle orifice and is the spray Weber number based on D and the nozzle velocity. A ring burner was designed and constructed for uniformly heating oil pool surfaces from above and igniting them. The resulting oil temperatures while the oil was heated to its flash point satisfied the one-dimensional transient heat conduction model for a semi-infinitely thick solid with a shallow heated layer near the surface. Water sprays actuated when the oil surface temperature reached its flash point rapidly cooled the heated layer and caused mixing with the cooler oil below. Fire suppression tests were conducted to determine the relationship between required water spray density, drop size, and oil temperature in order to achieve suppression. A data correlation using non-dimensional parameters was developed to quantify the fire suppression criteria for the high flash point oil fires. Oil pool fires with the higher flash point oils, such as the 291oC flash point soybean oil, could be suppressed with much lower water densities than those of the lower flash point (137oC) mineral seal oil. However, if the water spray drop sizes are sufficiently small, the lower flash point oil fires can also be extinguished with lower spray densities. The NFPA 15 specified critical water density (0.30 gpm/ft2, 12 mm/min) to extinguish high flash point pool fires is only valid for mineral seal oil when the drop size is lower than about 300 µm. It is valid with larger drop sprays only when the flash point of the oil is higher than 190 according to the correlation developed here. Spray-induced pool fire intensification tests were conducted under a fire products calorimeter for measuring heat release rates. Supplemental oil vaporization rate tests were also conducted to determine the contributions of oil vaporization and oil splattering to the intensified fire. Results showed that vaporization could only account for between 1% and 1.7% of the heat release rate in intensified mineral seal oil fires, and less than 1% of the heat release rate in intensified soybean oil fires. The remainder is due to spray-induced oil splattering, which increased with increasing drop Weber number as well as increased oil temperature. The heat release rate is enhanced by factor from 2.12 to 5.55 compared to the heat release rate of free burning cooking oil. For mineral seal oil, this ratio is in the range 0.92 to 1.25 for the spray conditions tested. Correlations with the dimensionless factors of and the Weber number of the water spray were also developed to quantify the ratio of the splattered oil to applied spray density."

An engineering method has been developed for calculating the blowdown of agent from a pressurized dry chemical fire suppression system supply cylinder, and the flow rate of agent through a piping delivery system. Its goal is to provide the means to determine the blowdown time and agent delivery capabilities of pre-engineered and simple engineered systems. The method is based on the treatment of the two-phase powder-gas flow as an equivalent fluid with thermodynamic properties that account for agent composition and the relative proportions of agent and gas propellant. The mixture is treated as compressible, and the expansion in the supply tank is assumed isentropic. A key assumption in the model is that the agent (powder) mass fraction remains constant, in both the tank and delivery system. Laboratory tests were conducted to examine the validity of the model and its assumptions. Simple systems were discharged to measure pressures in the cylinder and nozzle inlet during discharge, and the mass of agent discharged. A 0.43 cubic foot cylinder containing 0-25 lbm of either sodium bicarbonate or moammonium phosphate, pressurized at up to 300 psig of nitrogen, was discharged, either alone, or with an 8-foot length of piping and a single nozzle. For the cylinder by itself, gas alone pressurized to 300 psig discharged in 1.5 seconds, while 25 lbm of sodium bicarbonate agent pressurized to 300 psig discharged in 5.2 seconds with 0.10 lbm of agent remaining in the cylinder after discharge. There was no significant difference in the discharge times or residual masses in the cylinder after discharge between the sodium bicarbonate and monoammonium phosphate agents. For a cylinder-pipe-nozzle system, gas-alone discharges pressurized to 300 psig took 7 seconds, while 25 lbm of sodium bicarbonate agent pressurized to 300 psig discharged in 26 seconds with 0.64 lbm of residual agent in the cylinder after discharge. Predictions generated by the model were compared with test results. Cylinder alone gas-only discharge model predictions agreed well with test data for the full duration of tests using a discharge coefficient of 0.380 to characterize the gas flow through the dip tube / valve assembly; a simple isentropic analytical model gave a good prediction using a discharge coefficient of 0.430. Gas-solids predictions using a discharge coefficient of 0.500 agreed well with test data up to the observed inflection point near the end of discharge. This inflection point is caused by the agent in the cylinder reaching the bottom of the dip tube, resulting in reduced flow of agent from the cylinder, and thus reducing the mass fraction of the flow. Cylinder-pipe-nozzle model discharge predictions for gas-only discharges agreed well with test data for the full duration of tests using a discharge coefficient of 0.470 for the 0.173-inch diameter nozzle used in the testing. Model predictions agreed well with the gas-solids mixture test data up to the inflection point, using a discharge coefficient of 0.999. The constant mass fraction assumption results in residual agent mass predictions of 2.0 lbm or more after discharge. Test data shows 0.6 lbm or less of residual. This residual discrepancy, and the presence of the inflection point observed in solids-gas tests, suggests that the constant mass fraction assumption is not adequate to accurately model agent discharge from the cylinder. Using an appropriate discharge coefficient, the model can be used to determine approximate discharge times for simple systems.