Introduction. Assuming that the course of time has changed in a limited area of space near the Earth’s surface, the explosiveness of such an event is analyzed.

The object and foundations of the research method. In a spherically symmetric formulation of the problem, perturbations of an ideal gas (air) caused by a change in the course of time (by a relative magnitude θ of the order of ±10–12) in a stationary region of space were investigated. The solution of the problem is based on the assumption that it is legitimate to modify the known dependence of the clock readings on the location of the clock in an accelerated moving reference frame (Einstein, 1907), when the acceleration (cause) and the change in time course (effect) are permuted.

The results and their discussion. In the zone of time course change, a field acceleration series, which, in its effect on the air, is similar to the gravitational field. The boundary area of the zone acts as a “pump”, pumping ambient air into the zone or ejecting it from the zone in case of θ < 0 or θ > 0, respectively. At the same time, the air pressure and temperature in the zone respectively increase or decrease, in some cases, by orders of magnitude.

Indirect verification of results. It is made by applying the obtained results to the description of vortex motion and ball lightning.

Conclusions. A dimensionless parameter θ is introduced, expressing a local perturbation (change) of time course in relation to the time course in the rest of space, where θ = 0. A model is proposed for studying changes in atmospheric parameters in a zone where θ ≠ 0. The estimates of the extreme values of the parameters of the air condition in the zone for the cases of time course decrease (θ < 0) and increase (θ > 0) are performed. For the case θ < 0, the relaxation of the time course fluctuation (θ → 0) can be accompanied by an explosion. The model with θ > 0 can be used to explain the glow of a ball lightning that disappears without an explosion.

Introduction. Textile materials and products are fire hazardous, occupy a significant part of the space of public buildings (hotel facilities, auditoriums, etc.), however, fire safety requirements for them are not fully established, which makes it difficult to confirm compliance with fire safety requirements.

State of the issue. An analysis of the main regulatory documents in force in the Russian Federation containing fire safety requirements for textile materials and products in public buildings and structures is presented. It is established that they contain disparate and, in some cases, contradictory fire safety requirements, in addition, there is no unified methodological approach to assessing their flammability.

Research results and their discussion. Data are presented on the main current and currently being developed standard methods for classification assessment the flammability of decorative textiles depending on their purpose. Experimental studies of upholstered furniture products were carried out, methods of standard tests were developed, in which the specimen layout was established, the type of low-power ignition sources, the main parameters and criteria for classification assessment of flammability were substantiated. It was revealed that the most fire-hazardous products of upholstered furniture include compositions made of natural materials, used mainly as covers, upholstery and fillers.

Conclusions. A set of parameters and criteria for assessing the fire hazard of textile products is substantiated, a flammability classification is established, which is necessary to regulate their fire-safe application in premises of public buildings and structures, as well as to confirm compliance with the established safety requirements.

Introduction. The “Krasnoyarsk Pillars” National Park is a popular holiday destination that attracts many tourists from all over the world. The park’s location in a forest makes it vulnerable to forest fires. A tourist memo on fire safety rules indicates not to get into a ring of fire or to be in the path of a serious forest fire. The process of ensuring fire safety for tourists in the Park was not considered within the framework of the Federal Law of 24.11.1996 Nо. 132-FZ (as amended on 13.06.2023) “Fundamentals of Tourist Activity in the Russian Federation”. The law in Art. 7 directly indicates that a tourist is obliged to observe personal safet.rules during the trip, but also defines the list of Emergencies Ministry services that will be involved in rescuing a tourist in an emergency. In this regard, in order to ensure the personal safety of a tourist, it is important to develop optimal evacuation routes and notify about them in the event of a forest fire. Preserving human life and health is a primary task of the State.

Aims and objectives. The study aims to determine the fastest and therefore safest, evacuation route from the Park, taking into account the terrain features, distance to safe zones and multiple intersections of trails. The purpose of this study is to calculate the optimal evacuation route from the “Krasnoyarsk Pillars” National Park in the event of a forest fire, taking into account territorial features and obstacles. The optimal evacuation route exists under sufficient optima­lity conditions determined from the solution of the optimization problem in real time upon actual detection of a forest fire.

Methods. Achieving the set purpose is realized by an algorithm in the developed computer programme. It finds the shortest evacuation routes by solving the optimization problem of determining the minimum. To solve the problem, Dijkstra’s algorithm is used to find the shortest paths in the graph. As part of the research, the territory of the national park is modelled as a graph. The vertices of the graph are key points (lookout points, forks in paths, exits to roads), and the edges are paths and roads connecting these points.

Results. As a result of the research, a route was calculated and laid out, reflecting the optimal evacuation distance on the map of the area, which allows visitors to effectively evacuate themselves in the event of a forest fire so ensure their personal safety. Consequently, the Ministry of Emergency Situations can organize the evacuation process of tourists so make the tourist’s process of ensuring their personal safety optimal.

Conclusions. The optimal evacuation routes from the “Krasnoyarsk Pillars” National Park in case of a forest fire are calculated. This is an important tool for ensuring the personal safety of tourists and park employees. The results of the research can be used to optimize warning, evacuation and preparation for emergency situations in the future.

Introduction. When designing and constructing wooden buildings, regulatory documents stipulate a number of restrictions due to their low fire resistance. Fire breaks (distances) for such buildings are maximum, and an increase in their number of floors will lead to their additional increase. In this regard, it seems reasonable to conduct research in terms of assessing the optimal fire breaks to limit the spread of fire in wooden buildings to neighbouring facilities.

Aims and objectives. The aim of this work is to study by field modelling the peculiarities of fire behaviour of wooden structures to determine the quantitative characteristics of heat flows to neighbouring protection facilities for the selection of safe fire separation distances.

Research methodology. To achieve the purpose of the study, field modelling of fire dynamics using the FDS computer software package was used. During the simulation, the values of temperatures and heat fluxes to neighbouring objects from fires in wooden buildings were obtained.

The results and their discussion. As a result of modelling of fire development in wooden buildings of different number of floors, values of the intensity of thermal radiation on neighbouring objects were obtained, including taking into account the wind load. The results of the calculations made it possible to develop proposals for the application of the data obtained in the development of sound regulatory requirements for fire safety.

Conclusion. It is shown that in case of fires in buildings with structures made of unprotected wood, with an increase in the number of floors, an increase in thermal effects on neighbouring objects is observed. In the presence of wind in the direction of a neighbouring object, the thermal effect also increases. When assessing safe distances, the possibility of combined exposure to radiant and convective flows should be taken into account. In order to comply with the current regulatory values of fire-fighting distances, it is necessary to increase the fire resistance of wooden buildings by increasing the fire resistance limits and reducing the fire hazard classes of load-bearing and enclosing building structures.

Introduction. The necessity of research in the field of fire safety of an infrastructure of railway, waterway and air transport using hydrogen as a fuel is presented. The relevance of this study is stipulated by an expansion of works aimed on an application of hydrogen to various types of the transport. The aim of this study is a review of investigations in the area of the fire safety of the infrastructure for a hydrogen refueling (hydrogen transport). The main task is to identify gaps in the subject and results of already conducted research and to develop proposals for further work.

Analysis of investigations in the area of the fire safety of the refueling stations for transport using hydrogen as a fuel. Publications in international journals devoted to solving the problem of hydrogen use in transport were analyzed. Researches in this direction are carried out in many countries of the world, though practical realization of their results is relatively small. First of all, it is worth mentioning the creation of regular passenger railway transportations in Germany, although the scale of these transportations is small (only one local line operates). In Norway, the conversion of ferries to hydrogen fuel is nearing completion. The works in the field of hydrogen application in air transport are of exploratory nature.

Conclusions. Hydrogen is a promising type of motor fuel for various types of transport, including railway, marine and air transport. However, the results of the works published in scientific press testify to rather weak elaboration of fire safety issues. In this connection it seems necessary to carry out additional research in this area. The directions of these studies are outlined.

Introduction. A number of articles provide an assessment of the total number of fires, fire deaths and fire injuries in the world at the beginning of the 21st century. In accordance with these estimates, the average number of fires in the world was estimated at 10–12 million fires per year, the number of fire deaths of 100–120 thousand and the number of fire injuries in 300–350 thousand. Currently, information has appeared that allows you to revise and clarify the assessments presented above.

Purpose and objectives. The target of this study is a modern assessment of the main parameters of fires in the world on the basis of the latest data of the Fire Statistics Center of the International Association of Fire and Rescue Services (CPS CTIF) and the World Health Organization (WHO).

Analytical part. In accordance with the new assessments in number of fires, fire deaths and fire injuries for the period 2018–2022, it was found that the average number of fires in the world can be estimated
at 6–7 million, the number of fire deaths in 70–75 thousand, the number of fire injuries in 250–300 thousand. These estimates are almost 1.5 times lower than the assessments given earlier.
The dynamics of assessment of the WHO by mortality in the world is given as a result of the effects of fire, heat and hot substances for 20 years (2000–2020).
The article provides data on the distribution of fires by objects and by fire causes in various countries of the world in 2022. The main fire objects are: bushes, grass 26.5 % and residential buildings 23.1 %. The main fire causes are: careless handling of fire — 27 %, improper installation and operation of furnaces and fireplaces — 18 %.
The distributions of mortality and injury to people in fires by fire objects in the countries of the world in 2022 are given. The main objects where people are dying and injured in fires are residential buildings of 83 and 69.4 %, respectively.

Conclusions. After a quarter of the XXI century, the main parameters of the situation with fires can be estimated by the following numbers: the total number of fires in the world can be estimated at 6–7 million per year; the total number of fire deaths is 70–75 thousand per year; the total number of fire injured is 250–300 thousand per year.

Introduction. False alarms from automatic fire alarm systems can cause serious problems such as shutting down the operation of a facility, the release of fire extinguishing agents and the unnecessary use of fire service resources. It is particularly important to recognize that delaying the arrival of fire units due to false alarms can exacerbate the situation. The purpose of the analysis is to identify the causes of false alarms and to develop recommendations to improve its effectiveness.

The object of the study is the triggering of fire alarm systems (FAS) at the objects of mass gathering of people.

Materials and methods. Empirical methods and methods of system analysis were used in the study. Regression analysis using the method of least squares for different types of regression equations was carried out.

Discussion Results. False alarms were found to occur more frequently in facilities with large areas where a large number of detectors and sources of false alarms are installed. Studies have shown that facilities with increased human activity are at greater risk of false alarms. To reduce the probability of false alarms in large facilities, it is recommended that detectors be installed in locations with the lowest probability of false alarms.

Conclusion. As a result of regression analysis, the equations describing the relationship between the area of objects of mass stay of people and the number of false alarms of fire alarm systems were obtained. On the basis of the results of the analysis recommendations for reducing the number of false alarms are developed.