The creation of material resources reserves for the elimination of consequences of natural disasters and technogenic accidents (emergency situations — ES) is one of the main tasks ofUnitedStatesystem of prevention and response to emergency situations. A sufficient amount of material resources, their rational placement, proper storage and quality service ensures the ability quickly to liquidate the immediate danger to human life and health, the organization of paramount life support for the population in the disaster area.

Aims and purposes. There is an actual problem of preliminary assessment, accounting and justification of the spare parts reserve for work special technical means (STM) of the firefighting and rescue service in the course of emergency response, based on the principle of the necessary sufficiency and the maximum possible use of the available forces and means.

Methods. For the planning the required amount of spare parts for STM, taking into account their cost, as well as for substantiating the decision on the optimal number of repair teams capable of ensuring timely replacement of failed units in an ES or its consequences, the methods of queuing theory and queuing systems are applicable.

Results and discussion. The article proposes a method of calculating the optimal reserve of spare parts to ensure the normal operation of STM with economic justification, taking into account the material costs of their acquisition and maintenance of repair teams. There are presented the calculations that allow in practice to take into account the risks associated with insufficient reserve of spare parts and forced downtime of STM due to the inability to quickly troubleshoot during ES response and rescue operations. Practical recommendations for determination of economically expedient quantity of spare parts and number of the operators making repair of special equipment taking into account material costs and indicators of reliability are developed.

Conclusions. The problems of the article correspond to the modern directions of scientific support of operational activities of Emercom of Russia and due to the presence of a wide range of tasks related to the creation, storage, use and replenishment of reserves of material resources during the liquidation of consequences of natural disasters and technogenic accidents.

Introduction. It has been previously known that for gas explosions in an unconfined chamber the following rule applies: the larger the distance between gas ignition location and relief opening (window), the higher the explosion pressure. This statement is based on results obtained by a number of researchers, including ourselves. However, as demonstrated by recent physical experiments, it is valid only for window sizes comparable to those recommended by guidelines to ensure certain safety conditions. For smaller window sizes, this relationship is leveled out or even changes its sign.

Research objective is to determine the cause of inversed relationship between distance from the window to ignition location and explosion pressure. Tackling this objective is of scientific and practical importance.

Research methods and tools. Two mathematical model variants for gas explosion development in an unconfined chamber were employed to study the revealed phenomenon, i. e. simplified model and numerical model. The first one, i. e. simplified model, is based on chamber representation as lumped volume, and using the Clapeyron equation in differential form. It was obtained that besides known factors, such as window size, properties of outflowing gases, etc., explosion development is influenced by the area of flame front and the time when it approaches the window. Unfortunately, this model does not take into account the dynamics of last factors development altogether. This task can be handled by the other model, numerical, implemented in Vulkan-M software. It is based on solving the gas dynamics equation system using large-particle method in Eulerian representation with added flame propagation conditions. Besides, Vulkan-M can visualize the physical process evolution, as well as record how its parameters and indicators develop.

Research results. It was found that if the window size is comparable to regulatory values, such a strong influence of window position on pressure is due not only to the difference of out flowing gas properties (initial mixture and combustion products), but also dueto the factthatin the initial period of explosion development the flame front area is much larger for a further removed window than in case of a small distance between the window and ignition location. For a smaller window, the pressure increase rate in the initial period is high and almost identical for both explosion scenarios. Therefore, combustion time becomes decisive for the maximum pressure value. If the window is located far from the ignition, combustion time is shorter than in case of a smaller distance. As a result, maximum pressure in the second case is higher than in the first case. This explains the revealed phenomenon.

Conclusion. The larger the window size, the stronger it affects the explosion pressure. This influence is determined not only by gas outflow, but it intensifies, sometimes significantly, due to the influence on flame front development. If the window size is decreased, its influence on flame front development is weakened and becomes negligible. In this case, the explosion pressure is affected by combustion time, besides window size.

Introduction. Systems of decision-making support, which are applied when managing fire-extinguishing operations, allow reducing direct financial damage and number of dead and wounded. The work in question is devoted to the construction of the risk model based on the decisions taken by the Fire Ground Commander (FGC) being the Decision Maker (DM) in the context of extinguishing the fire in a multi-storey building.

Aims and problems. The objective of the research is the construction of a model that would demonstrate the risk level contained in the decisions of the FGC. In order to achieve the objective it is necessary to solve the following problems: 1) to choose the type of a decision taking model; 2) to build the algorithm of model parameter estimation using the decisions taken by the FGC; 3) to analyze the model's quality.

Methods. The model class called Nature Games has been chosen. The procedure of DM's decision taking process observed while extinguishing the fire in a multi-storey building has been presented as a three-level decision tree. It was transformed into a normal (table) form, thus presenting the decision choice as the Hurwitz Criterion. Hurwitz's parameter of pessimism/optimism demonstrates the risk level contained in the DM's decisions. Simulation modelling has been performed in ordertocheckthe working capacity of the suggested Hurwitz parameter estimation technology.

Results and discussion. Simulation experiments proved the working capacity of the suggested technology on assessingthe DM'sdegreeof risk proneness. The estimates that have been built for different DM allow comparing the risk proneness degree of different FGCs. It provides a possibility to build model estimates based on the decisions taken by the experienced FGC. Estimates of other FGCs thus could be compared with the model ones, drawing conclusions on their management quality.

Conclusion. The objective of the research has been achieved due to solving the set problems. The suggested technology is a high-potential type of machine education that can be used both as a part of the DM's decision taking support systems and when training personnel whose role involves emergency operation control.

Introduction. Introductory part of this paper considers the actuality and importance of taking into account the requirements for fire safety (FS) at the production facilities of the fuel and energy complex (FEC) in the working process. The process of development of virtual twins of these objects should include planning of FS measures considering the requirements for information security (IS). There are noted the necessity of definition of strategic goals in such modeling. Authors propose strategic planning apparatus to improve the quality of created virtual prototypes. This kind of planning allows to take into account the many risks identified by the expert group. The objective of scientific research is to obtain a model by which it is possible to assess the features of the provision of FSand IS.

Methodology. The strategic goal associated with the performance of the production functions of the FEC facility, on which profit depends, is defined. To simplify the model dangerous factors were distributed into independent categories: risks of negative consequences connected with FSand IS, environmental pollution and process stoppage due to external inspections. The output of the expert and calculated values is presented for each category. Expert evaluations can be obtained using inverse symmetric pairwise comparison matrices and calculated evaluations using category grading on the damage scale. The probability function correlates with each part of the FEC facility. The negative impact of the dangerous factors is calculated that way.

Results. It is possible to obtain a matrix of distribution of influence of dangerous factors using the probability function selected in the study. The above procedure is used for the second and third levels of the hierarchy of influence. The second level includes factors, the third —measures to prevent the influence of dangerous factors. The final result is obtaining the distribution of the impact of activities on the parts of the FEC facility.

Conclusion. Finally, it was noted advantages of digital twin technology in planning FS of facilities of the FEC. The use of strategic planning allows to develop a digital twin model, taking into account the impactof activities on the achievement of the objectives of ensuring of FS and IS.

Introduction. The organization of radio communication at the fire, as an important part of the fire units operating management, should be given a considerable attention. The effectiveness of fire units operating management depends largely on thesteady of the radio network operation, in which, depending on the complexity of the situation, can work different officials who control the process of extinguishing the fire.

Methods. Modelling of radio network operation is based on Queuing theory methods. A list of n States in which the communication network and the corresponding transition graph can is compiled. Taking into account the generally accepted assumptions on the basis of the transition graph, a system of n differential equations connecting the probabilities of States and the intensity of the transition to these States is compiled. The stationary case is considered. Based upon the obtained solutions the efficiency of the radio network is estimated.

Results. The article presents three variants for which the possible States are described, graphs are constructed and systems of equations are composed. In the first variant, three officials interact inside the radio network, in the second, four officials interact. In the third variant the option of interaction between four fire units operating management with other hierarchy of management is considered. In the first two cases, analytical solutions for the States probabilities are obtained, for the third case, a solution using numerical methods is proposed. For each case, the critical States affecting the control stability are determined. The obtained solutions are followed by examples.

Conclusion. The possibility of modeling the radio communication network at the fire, as an important element of controlling of fire departments operating is demonstrated. Three variants of interaction between officials with use of a radio communication network are given. The mathematical models developed for the under consideration cases allow to estimate the probably characteristics of the radio network functioning. It allows us to assess the possibility of the probably of critical modes appearance that affect the effectiveness of the fire units operating management and the success his implementation.

Describes the historical background of the creation of the predecessors of robotic fire-extinguishing system (RFS) — plants homing to the fire. The information on the successful use of mobile robots in the military, police, fire protection, unmanned aircraft, industry, transport, construction, agriculture, social sphere, for the investment of human life conditions, during scientific research is presented. Shown fundamental differences between stationary RFS firefighters from mobile robots. The practical reasons preventing the implementation of the widespread use of RFS at the end of the last century are indicated. Brief information on the use of robotic fire monitor (RFM) for liquidation of the accident at the Chernobyl NPP is given. The analysis of the results of experimental and theoretical studies of the point of standing and scanning jets is carried out. Described the main problems encountered in the design process of RFS, which include RFM. It's shown the status of fire robots technology abroad. Russia's positions in the creation and production of RFM, in the development of the regulatory framework in relation to RFS have been noted. The basic terms and definitions on navigation and parameters of fire extinguishing agent supply are formulated. The analysis of the main provisions of normative documents on the design and testing of RFS is carried out. Comparative full-scale tests of domestic RFS and foreign sprinkler automatic fire extinguishing system are presented, made by the Denmark company COWI A/S. Investigated variants of the algorithm of functioning of the detection and navigation of the trunk of RFM to the fire with respect to the error of aiming and positioning. Different variants of implementation of the principle of operation of modern RFS are considered.

Introduction. The tactical capabilities of fire intelligence groups depend on various factors. It is also important to use information from mobile and stationary fire monitoring systems. The aim of this work is to assess the tactical capabilities of fire intelligence groups without using and using infrared technologies in the fire monitoring system. The paper solves two problems: the analysis of the electromagnetic light spectrum; a model for assessing the tactical capabilities of fire intelligence groups in the monitoring of fire in the building using short-wave infrared technologies.

Methods. In the paper there were used mathematical methods, including the method of decomposition of the normalized index of tactical capabilities in theTaylorseries to describe the tactical capabilities of intelligence groups in the fire.

Results and discussion. Based on the calculations of the performance and the area of the search area for intelligence teams, the graphs of the search area versus the indicator of the tactical capabilities of the fire intelligence groups and the normalized indicator of the tactical capabilities of the fire intelligence groups were plotted. It is shown that the performance of the intelligence teams depends on the speed of the units of the gas and smoke protection service, the number of units, the effective distance between the units and visibility conditions. In the paper it was proposed the use of short-wave infrared cameras to improve visibility in the smoke during the search and rescue of victims.

Conclusion. In the end, it is assumed that the system using infrared technologies will improve 10-15 % visibility for fire links, as well as improve the coordination of fire links. This, in turn, will allow to increase the efficiency of management decision-making in the search and rescue of victims in an inhospitable environment.

It is recommended to determine the number of fire hydrants (FG) simultaneously used in the fire extinguishing, as well as the minimum water consumption for firefighting according to the table, which presents all types of buildings, structures and premises in accordance with their functional purpose according to F1-F4.