Russian Views on Countering Terrorism During Eight Years of Dialogue Extracts from Proceedings of Four U.S.-Russian Workshops (2009) / Chapter Skim
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Special Characteristics of Firefighting in Urban Areas--Nikolay P. Kopylov
Special Characteristics of Firefighting in Urban Areas--Nikolay P. Kopylov
Pages 179-198
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From page 179... ...
Firefighting and rescue activity during a terrorist attack are affected by special factors not common in usual firefighting and rescue practice. Explosions partially or completely destroy buildings, which changes the fire development scenario, decreases the fire resistance of structures, and causes hazards for firefighters, rescue workers, and civilians.
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From page 180... ...
The main purpose of the research was to obtain information necessary for estimating the necessary fire resistance rating for building structures. The impact of a Boeing-767 into the World Trade Center was considered as a model situation.
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From page 181... ...
It indicates that if the mass of spilled fuel is more than 30 metric tons, the combustion process soon stabilizes and is characterized by a certain average ambient temperature in the enclosure. The duration of the stable period depends on the quantity of fuel.
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From page 182... ...
If the mass of spilled fuel is less than 10 tons, a stable combustion regime is not achieved because of the lack of fuel. Figure 2 depicts temperature curves describing the combustion of 90 tons of kerosene in an enclosure with opening areas of various sizes.
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They are correlated with ambient temperature dependences. Furniture Fire Figure 7 shows average ambient temperature dynamics in an enclosure for a case in which the combustible load is common and consists of furniture.
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From page 184... ...
T, °C FIGURE 5 Dynamics of the temperature of the enclosure walls with different quantities of combustible spilled kerosene.
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From page 185... ...
COUNTERING URBAN TERRORISM 185 90 t of kerosene quarter opening half opening double opening triple opening T,T, °C °C FIGURE 6 Dynamics of the temperature of the enclosure walls during combustion of 90 metric tons of kerosene with different sizes of opening areas. standard fire T, °C FIGURE 7 Dynamics of average temperature in the enclosure with various quantities of furniture.
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From page 186... ...
A stable regime is achieved later than with the kerosene fire because the furniture fire spreads more slowly. The construction temperature curves for the furniture fire correlate well with the curves for the kerosene fire (Figures 7 and 8)
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From page 187... ...
That result correlates with U.S. researchers' estimates that each plane had approximately 30 metric tons of fuel onboard prior to impact.3 Estimate of Fire Endurance of the Damaged Construction Elements Experimental studies were conducted to estimate the effect of mechanical damage on fire resistance time for two types of structural elements: floor panels 3Hamburger, R., W
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From page 188... ...
A 200-millimeter transverse chip at the middle of the panel exposing half the diameter of the reinforcement bars decreases fire endurance time by 50 percent. The higher the exposure coefficient for the reinforcement bars, the lower the fire endurance time for the damaged column (for e = 0.03, fire endurance time falls by 6 percent, and for e = 0.14, fire endurance time falls by 21 percent)
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From page 189... ...
TABLE 1 Theoretical and Experimental Results of Column Fire Resistance Estimates Reinforcement bar Fire resistance exposure coefficient e time , min.
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From page 190... ...
Therefore, rescue and firefighting operations should be performed quickly in order to save as many trapped victims as possible. Subway Fires Crowds of people, a limited number of evacuation exits, long evacuation paths, and fast-changing hazard dynamics during a fire make subway stations and trains especially dangerous places.
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In recent years, subway trains have become more frequent targets of terrorist attacks. The Tokyo subway was attacked by terrorists using poisonous gas (sarin)
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These calculations were based on the results of large-scale fire experiments conducted on a real train car in an experimental tunnel. Temperature dynamics in points between the cars is presented in the diagram.
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Smoke concentrations reach dangerous levels in 7–12 minutes, which allows enough time to evacuate people during rush hour. If the emergency ventilation system is not switched on immediately or is ineffective, smoke obscures the evacuation exits within 1–2 minutes.
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Evacuation time in this first model equals 24.4 minutes. The results of the calculations indicate that the critical values for the accumulation of people in the evacuation routes are not achieved.
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From page 195... ...
It is shown that the width of the evacuation pathway is the most important factor affecting estimated evacuation time. For the third model for the 1.4 mwide staircase, critical values for the accumulation of people in the evacuation routes are achieved in the first minute of the evacuation and are maintained until the end of the process.
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From page 196... ...
Reconnaissance showed the area of the fire to be approximately 800 m2, and the nearest fire hydrants were within the terrorists' firing range. The fire department officer in charge decided to employ two hoses supplied by a fire truck water tank, using nearby buildings and structures as cover.
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From page 197... ...
The hoses were supplied by water carried to the spot in turns by fire truck water tanks. After two more fire vehicles from the special fire brigade of Vladikavkaz and a fire truck from the Ardon fire brigade arrived, a hose line was laid out to supply water from a distant hydrant located in a safe zone.
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