The issue of protection of residential buildings against gas mixture explosion in which glazing windows are considered as safety structures (SS), which are mounted in the depth of a window aperture, is considered. It is shown that when the fastenings, fixing the window frames to the wall of the building, are destroyed, the SS starts moving inside the aperture, the area for the gases discharge does not open, and the explosion occurs in the conditions of a sealed volume. It has been established that for small spaces (30–150 m³) the rise time of pressure in an internal explosion is comparable to the movement time of the SS inside the aperture. The magnitude of the pressure increase during the movement of the SS inside the aper­ture has been determined. A dimensionless parameter has been selected that determines the pressure increase from the moment the SS begins to move until the aperture opens for gas outflow. It has been shown that twofold or tenfold pressure increase can cause destruction before its discharge. An expression for de­termining the speed of the SS at the moment of opening the aperture has been obtained, and this speed mainly determines the rate of pressure discharge due to the gases outflow. It has been established that the pressure increase during the movement of the SS inside the aperture exceeds the pressure increase pressure after the opening. It was revealed that when testing and designing SS, it is necessary to take into account the depth of SS embedment depth in the aperture, especially for residential premises, the volume of which does not usually exceed 120 m³.

Introduction. The management of municipal solid waste (MSW) is one of the important problems of our time. Security is only possible when solving this problem.

The amount of MSW is steadily increasing. The project of garbage transportation from Moscow and St. Petersburg by railway is begins to have results to solve problems related to waste management.

The purpose of this work is to substantiate the possibility and advantages of using the exergy fire risk assessment of transportation of MSW in railway transport.

Theory and calculations. The concept of chemical exergy is used to effectively design energy conversion processes, study the level of environmental impact of equipment and technologies, and determine the possibility of minimizing it.

The exergy method can be applied to the assessment of energy-ecological efficiency and the fire hazard of the transport of dangerous waste by train.

Analysis of changes in the morphological composition of the waste was implemented from the 20^s of XX century to the present. Formulas for calculating chemical exergy and HHV of MSW were presented.

Results and discussion. The values of chemical exergy and HHV of MSW are determined. An in­crease in the values of these indicators was acknowledged, which is determined by changes in the morpho­logical composition of the waste.

The dependence between exergy and HHV for the components of MSW was obtained, the correlation coefficient is R² = 0.975. The dependence between the exergy of TCR of different morphological composi­tion and the HHV, R² = 0.977, was built. As a result, an analysis of changes in these characteristics was proven by years and the determinated by cities in Russia.

It was proposed to introduce the concept of “exergy” in the procedure for determining the hazard class of MSW. The advantages of the exergy assessment of the fire danger of traffic on the railway transport are revealed.

Conclusion. The exergy approach allows to comprehensively address the issues of energy-ecological efficiency and fire hazard of waste management processes in railway transport. Accounting for indicators of fire hazard through exergy when assigning the hazard class MSW contributes to improving the safety of traffic on the railway transport.

Introduction. Nowadays ultrasonic welding of metals including conductors is widely used. The con­nection of copper conductors by ultrasound is based on high-frequency oscillations.

Materials and methods. Copper stranded conductors interconnected by ultrasonic welding were chosen as the materials for the study. The study of these samples was carried out in the laboratory by metallographic analysis.

Results and discussion. In case of a poor contact at the connection point, a large transient resistance may occur when an electric current passes through a given point and cause fire.

To establish the involvement of a poor adhesion to the occurrence of a fire, it is necessary to conduct metallographic studies of the compound. With qualitatively performed welding, fusion of individual sections of wires at the junction site is observed, while in the case of a “poor” connection, clearly defined boundaries are observed.

A very long exposure to ultrasound in the welding process on the connected conductors leads to a de­crease in the plasticity of the conductor, which in turn leads to the fracture of the veins near the junction and, as a consequence, to the emergence of local current overload. Where the places of rupture after the fire are melted and smoked, indicates that the test conductor was damaged even before the ignition of the vehicle.

Conclusion. Thus, the possibility of vehicle combustion as a result of a poorly executed connection of conductors by ultrasonic welding is shown. It is noted that the fire can be caused by uncompleted welding (“non-fusion” of the conductors), or vice versa when an impact of ultrasonic waves on the conductors to be connected has been too long.

It is necessary to withdraw this connection directly at the seat of fire for further laboratory metallo­graphic research.

Introduction. Currently, the risk assessment method is widely used at the facilities. This is true in determining the chemical hazards arising in the storage infrastructure and transport of chemically dangerous substances. The basis of risk assessment analysis of chemical hazard is forecasting of the consequences of chemical accidents and contamination areas.

Methods. As a result, it was revealed that the methods contain wrong assumptions. In particular, the actual area of chemically dangerous substance spill and its absorption into the underlying surface are not taken into account. These assumptions are proposed to be eliminated by use spreading and infiltration coefficient in the risk assessment method of chemical hazards. These coefficients are calculated on the basis of experiments to determine the area of the spill and the proportion of infiltration in the underlying surface of the main types of chemically dangerous substance. The spreading surface coefficient clarifies the main features that effect on evaporation time, the area of the spill and the thickness of the film of chemically dangerous substance spill on the underlying surface.

Results and discussion. Infiltration coefficient determines the amount of chemically dangerous sub­stance absorbed into the underlying surface. In addition, it is not taken into account in the secondary cloud formation of chemical contamination. The article presents the coefficients that are calculated for the main types of chemically dangerous substance and ways to obtain them. An assessment of the chemical hazard was carried out using an improved methodology in the Republic of Mordovia. The procedure is compared with other methods.

Conclusion. Calculations show that the proposed methodology for chemical risk assessment will allow more accurate forecasting. It is better to assess the risk of chemical hazards.

Introduction. The woods have the crucial functions on decrease of negative impact natural and anthropogenous character to the ecosystems of Earth. As difficult objects of research, the woods depend on a host of factors but unfortunately it is paid attention not to all of them, especially when forecasting of fire situation in the woods. Research objective — carrying out of an analysis of modern forecasting methods of fire-dangerous situation and development of the recommendations for improvement of complex of activities for prevention and mitigation of consequences of forest fires.

Methods. The leading documents and approaches used for forecasting of fire-dangerous situation, realization of actions for the prevention and elimination of emergency situations were analyzed.

Results. It is evaluated that the method of calculation of fire hazard index under the terms of weather determined by the order of Federal Forestry Agency doesn’t consider the speed of a wind and accumulated precipitation that has essential impact on reliability of the defined degree of fire hazard. For the elimination of this shortcoming it is offered to use corresponding correction coefficients. Geometrical characteristics of forest fire have essential impact on a choice of methods of fire extinguishing. The technique of landscape fire extinguishing used simplifies its form to a square that leads to increase of calculations error and decrease efficiency of planning and carrying out of accident rescue works. It is offered to use an ellipsoid or sector which calculation of the areas isn’t required difficult mathematical calculations, but possesses a sufficient share of accuracy. Improvement of a complex of organizational, legal and engineering and technical measures is directed on increase of efficiency of implementation of measures for the prevention and fight against forest fires.

Conclusion. The research allows to make a conclusion that the existing methods and actions not fully ensure safety of the population and territories at threat of emergence of natural fires. The offered measures directed on improvement of the available expected methods will allow to increase efficiency of the forecast and realization of accident and rescue works during natural fires.

The problem of quantitative assessment of survivability of networks of the fire-fighting water supply at the enterprises of petrochemical industry as internal (corrosion, pressure throws) and external (explosions of technological installations, earthquakes) can lead to damage of various sites of networks is considered. The definition of the concept of survivability of external fire water supply networks in comparison with similar formulations in relation to other objects is given. Quantitative indicators of survivability assessment are substantiated, examples are given.

The regulatory documents regulating the procedure for checking the state of electrical installations of buildings and structures are considered. The existing contradictions and disagreements in the field of fire safety of electrical networks and equipment with voltage up to 1000 V are noted. Examples of the occurrence of difficulties during inspections of the fire-prevention state of electrical installations by supervisory authorities are presented. The ways to resolve existing disagreements in order to reduce the number of fires from electrical installations are proposed.