Lecture
Objective: to develop students' knowledge of man-made (technogenic) emergency situations, the main causes of their occurrence and the consequences of technogenic accidents, to give a general idea of the classification of man-made emergency situations; to familiarise them with the algorithm of action in technogenic accidents.
1. The concept of an accident and a catastrophe.
An effect of environmental ill-being is the steady rise in the incidence of disease among the population of various regions of the world. A major negative influence on all spheres of life was exerted by the largest technogenic catastrophe, at the Chernobyl nuclear power plant in 1986.
The growth in the scale of economic activity and the number of industrial complexes, the concentration in them of high-capacity units and installations, and the use of significant quantities of potentially hazardous substances in production – all these factors increase the probability of technogenic accidents occurring.
Man-made emergency situations carry a threat to people, the economy and the environment. They arise, as a rule, at potentially hazardous production facilities, which primarily include chemically hazardous, radiation, fire-and-explosion-hazardous and hydrodynamic facilities, and in recent times accidents and catastrophes in transport have increased significantly.
Modern production is constantly growing more complex. It increasingly employs toxic and aggressive components. Various modes of transport carry large quantities of chemically hazardous, fire-hazardous and explosion-hazardous substances. All this increases the probability of accidents occurring and their severity.
Of the emergency situations that occurred in 2000, almost two-thirds were of a man-made nature.
The causes of the occurrence of emergency situations in the technogenic sphere are well known: the deterioration of production assets, the obsolescence of technological equipment, the absence of control over hazardous production processes, weak discipline, and a negligent attitude toward one's duties. As a rule, it is these causes that lead to the occurrence of accidents and catastrophes.
By scale of spread and taking into account the severity of the consequences, all man-made emergency situations are local (facility-level), local (municipal), or territorial.
Emergency situations are classed as local (facility-level) when the damaging factors and the effect of the source of the emergency do not extend beyond the production site or facility and can be eliminated using the facility's own forces and resources.
Emergency situations are classed as local (municipal) when the damaging factors and the effect of the source of the emergency do not extend beyond the populated area, town or city (district).
Emergency situations are classed as territorial when the damaging factors and the effect of the source of the emergency do not extend beyond the subject (republic, krai, oblast, autonomous entity).
There is also the concept of a — global emergency situation, in which the damaging factors and effects of the emergency situation extend beyond the borders of the state.
2. Classification of accidents and catastrophes according to the causes of their occurrence.
-Transport accidents (catastrophes) can be of two kinds: those occurring at production facilities not directly connected with the movement of vehicles (in depots, at stations, in ports, at air terminals), and those that happen while vehicles are moving. The second kind of accident is characterised by the remoteness of the emergency from major populated areas, the difficulty of delivering rescue teams there, and the large numbers of casualties requiring urgent medical assistance.
-Fires and explosions - are the most widespread emergencies. They occur most often, and as a rule with severe social and economic consequences, at fire- and explosion-hazardous facilities. These are, above all, industrial enterprises that use explosive and readily combustible substances in their production processes, as well as rail and pipeline transport, which bears the greatest burden in moving fire- and explosion-hazardous cargo.
-Accidents involving the release (or threat of release) of hazardous chemical substances (HCS) - are incidents connected with the leakage of harmful chemical products during their production, storage, processing and transportation.
-Accidents involving the release (or threat of release) of radioactive substances. They occur at radiation-hazardous facilities: nuclear power stations, enterprises for the manufacture and reprocessing of nuclear fuel, the disposal of radioactive waste, etc. Accidents involving the release (or threat of release) of biologically hazardous substances are not a frequent occurrence, apparently explained by the strict secrecy of work in this field and, at the same time, by well-thought-out measures for preventing the occurrence of such emergencies. However, given the severity of the consequences should biologically hazardous substances enter the environment, such accidents are the most dangerous for the population.
-Sudden collapses of buildings and structures most often do not occur by themselves but are triggered by secondary factors: a large gathering of people in a confined area; strong vibration caused by passing railway trains or heavy-duty trucks; excessive loading of the upper floors of buildings, etc.
-Accidents in power-supply systems and municipal life-support systems rarely lead to loss of life. However, they substantially hinder the population's daily life (especially in the cold season) and can cause serious disruption or even the suspension of the operation of industrial and agricultural facilities.
-Accidents at industrial treatment facilities lead not only to a sharp negative effect on the personnel operating these facilities and residents of nearby populated areas, but also to sudden releases of poisonous, toxic and simply harmful substances into the environment.
-Hydrodynamic accidents arise mainly from the destruction (breach) of hydraulic engineering structures, most often dams. Their consequences are damage to and failure of hydraulic facilities and other structures, injury to people, and flooding of extensive territories.
Many accidents and catastrophes trigger other accidents. For example, an accident on a municipal gas pipeline led to an explosion in a residential building, which in turn caused the building to collapse and a fire to break out.
An accident on a trunk pipeline predetermined a gas explosion near a railway line. As a result of the explosion, some carriages were derailed, a fierce fire broke out, and the power grid, communication lines and the railway track were damaged.
But not all accidents develop into emergencies. For example, a vessel sinks, but the crew is saved. An empty railway carriage is derailed — there are no casualties. A truck falls into a river — the driver escapes.
There are quite a few such situations and events occurring every day. But they are not classed as emergencies if these events involve no human casualties, no significant material losses, and no disruption of people's living conditions.
The same can be said of leaks of gas, water or poisonous substances, if these events affected no one and were eliminated right at the outset without causing significant adverse consequences.
3. Personal safety in emergency situations. Algorithm of action in technogenic accidents.
Fires and explosions in residential and administrative buildings.
A fire is defined as uncontrolled combustion causing material damage and harm to the life and health of citizens, and to the interests of society and the state.
Main damaging factors of a fire:
Open flame. Cases of direct exposure to open flame
are rare among people. Injury most often results from the radiant heat emitted by the flame.
Ambient temperature. The greatest danger to people is posed by inhaling heated air, which leads to burns of the upper respiratory tract, suffocation and death. Thus, at a temperature above 100 C a person loses consciousness and dies within a few minutes. Skin burns are also dangerous.
Toxic combustion products. In fires in modern buildings constructed using polymer and synthetic materials, people can be affected by toxic combustion products. The most dangerous of these is carbon monoxide. It reacts with the haemoglobin in blood 200-300 times faster than oxygen, which leads to oxygen starvation. A person becomes indifferent and apathetic to danger: numbness, dizziness, depression and impaired coordination of movement are observed. The end result of all this is respiratory arrest and death.
-Loss of visibility due to smoke. The success of evacuating people during a fire can be ensured only if their movement is unobstructed. Evacuees must be able to clearly see the emergency exits or exit signs. When visibility is lost, people's movement becomes chaotic. As a result, the evacuation process is hindered and may then become unmanageable.
-Reduced oxygen concentration. In a fire, the concentration of oxygen in the air decreases. Meanwhile, a reduction of even 3% causes a deterioration of the body's motor functions. A concentration below 14% is considered dangerous; at that level, brain function and coordination of movement are impaired.
Causes of fires.
In residential and public buildings, a fire mainly arises from faults in the electrical wiring and appliances, gas leaks, ignition of electrical appliances left energised and unattended, careless handling and children's mischief with fire, the use of faulty or homemade heating appliances, the doors of furnaces (stoves, fireplaces) being left open, the discharge of hot ash near structures, and carelessness and negligence in handling fire.
The causes of fires at public enterprises are most often: violations committed during the design and construction of buildings and structures; failure by production personnel to observe basic fire-safety measures, and careless handling of fire; violation of fire-safety rules of a technological nature during the operation of an industrial enterprise (for example, when carrying out welding work), and also during the operation of electrical equipment and electrical installations; the use of faulty equipment in the production process.
The spread of fire at industrial enterprises is aided by: the accumulation of significant quantities of combustible substances and materials in production and storage areas; the presence of routes creating the possibility for flame and combustion products to spread to adjacent installations and neighbouring premises; the sudden appearance, during a fire, of factors that accelerate its development; delayed detection of a fire that has broken out and delayed notification of the fire brigade; the absence or malfunction of fixed and primary fire-extinguishing equipment; incorrect actions by people when extinguishing a fire.
The spread of fire in residential buildings most often occurs because of the inflow of fresh air, providing an additional supply of oxygen, through ventilation ducts, windows and doors. This is why it is not advisable to break the glass in the windows of a burning room or to leave doors open.
In order to prevent fires and explosions, and to preserve life and property, one must avoid keeping stocks of flammable and combustible liquids in the home, as well as substances prone to spontaneous combustion and capable of exploding. Any small quantities of these that are kept should be stored in tightly closed containers, away from heating appliances, and should not be subjected to shaking, impact or spillage. Particular care should be taken when using household chemical products: do not throw them down the refuse chute, do not heat mastics, varnishes and aerosol cans over open flame, and do not launder clothes in petrol. Furniture and combustible materials must not be stored on stair landings; attics and basements must not be cluttered; storerooms must not be set up in the niches of plumbing cabinets; and waste paper must not be collected in refuse chambers. It is not advisable to install electric heating appliances near combustible objects. Switches, plugs and sockets for power supply and electrical appliances must be kept in good working order. It is forbidden to overload the electrical network or to leave switched-on electrical appliances unattended; when repairing the latter, they should be disconnected from the mains. The most fire- and explosion-hazardous household appliances are televisions, gas stoves, water heaters and others. They must be operated in strict accordance with the requirements of their instructions and manuals.
If the smell of gas appears, one must immediately shut off its supply and air the premises; at the same time it is strictly forbidden to switch on lighting, smoke, or light matches or candles. To avoid gas poisoning, all people not engaged in eliminating the fault in the gas stove or gas pipeline should be removed from the premises.
It is forbidden to block access routes to buildings or approaches to fire hydrants, to lock the doors of shared hallways in apartment buildings, to block easily destructible partitions and balcony hatches with heavy objects, or to close off the openings of the air zone of smoke-free stairwells. Fire-automation equipment must be kept in working order, and fire alarms, the smoke-removal system and fire-extinguishing equipment must be kept in serviceable condition.
Actions of the population when fires occur.
In the event of a fire, one must urgently leave the building, using the main and emergency (fire) exits or stairs (using lifts is dangerous), and call the fire service as quickly as possible, reporting one's full name, address and what is burning.
In the initial stage of a fire's development, one can try to put it out using any available fire-extinguishing means (fire extinguishers, internal fire hydrants, covers, sand, water, etc.). It must be remembered that fire on electrical-supply elements must not be extinguished with water. The power must first be switched off, or the wire cut with an axe with a dry wooden handle. If all efforts prove futile and the fire spreads, one must urgently leave the building (evacuate). When stairwells are filled with smoke, the doors opening onto them should be closed tightly, and if a dangerous concentration of smoke builds up and the temperature in the room rises, move onto the balcony, taking a dampened blanket (a rug or other dense fabric) to shelter from fire should it penetrate through the door and window openings; the door may be pulled to behind oneself.
Evacuation should continue via the fire escape or through another apartment, if there is no fire there, using firmly tied sheets, curtains, ropes or a fire hose. Descent should be one person at a time, supporting one another. Such self-rescue involves risk to life and is permissible only when there is no other way out. One must not jump from the windows (or balconies) of upper floors of buildings, as statistics show that this ends in death or serious injury.
When rescuing casualties from a burning building, before entering, cover your head with a wet blanket (coat, raincoat, or a piece of heavy fabric). Open the door into a smoke-filled room carefully, to avoid a flash of flame from the rapid inflow of fresh air. In a heavily smoke-filled room, move by crawling or in a crouch, and breathe through a moistened cloth. If a casualty's clothing has caught fire, throw some kind of cover (coat, raincoat) over them and press it tightly to cut off the flow of air. When rescuing casualties, take precautions against possible collapse, cave-in and other hazards. After carrying the casualty out, give them first aid and send them to the nearest medical station.
Explosions and their consequences. Actions of the population during explosions.
An explosion is a suddenly occurring (rapid, instantaneous) event in which a short-lived process of conversion of matter takes place, releasing a large amount of energy within a confined volume.
The scale of the consequences of explosions depends on their power and the medium in which they occur. The radii of the damage zones can reach several kilometres. Three zones of explosive action are distinguished.
Zone I- the action of the detonation wave. It is characterised by an intense shattering effect, as a result of which structures break up into separate fragments flying away from the centre of the explosion at high speed.
Zone II - the action of the explosion products. Complete destruction of buildings and structures occurs in this zone under the action of the expanding explosion products. At the outer boundary of this zone, the shock wave that forms separates from the explosion products and continues to move independently away from the centre of the explosion. Having exhausted its energy, once the explosion products have expanded to a pressure corresponding to atmospheric pressure, they no longer produce any further destructive effect.
Zone III - the action of the air shock wave. At the outer boundary of Zone III the shock wave degenerates into a sound wave, audible at considerable distances.
Causes of explosions. At explosion-hazardous enterprises, the most common causes of explosions are: destruction and damage of production vessels, equipment and pipelines; deviation from the established technological regime (excess pressure and temperature inside production equipment, etc.); lack of constant monitoring of the serviceability of production equipment and machinery and of timely scheduled repair work.
Explosions in residential and public buildings, as well as in public places, pose a great danger to people's life and health. The main cause of such explosions is the unreasonable behaviour of citizens, above all children and adolescents. The most frequent occurrence is a gas explosion. However, in recent times, cases involving the use of explosive devices, and above all terrorist acts, have become widespread.
To instil fear, terrorists may organise an explosion by placing explosive devices in the most unexpected places (basements, rented premises, rented flats, parked cars, tunnels, the metro, public transport, etc.), using both industrially manufactured and improvised explosive devices. Not only the explosion itself is dangerous, but also its consequences, which as a rule take the form of the collapse of structures and buildings.
The danger of an explosion can be judged from the following signs: the presence of an unknown package or some item in a car, on a staircase, in a flat, etc.; a taut wire or cord; wires or insulating tape hanging out from under a car; someone else's bag, briefcase, box, or any object found in a car, at the door of a flat, or in the metro. Therefore, if you notice a suspicious explosive object (an improvised explosive device, a grenade, a shell, a bomb, etc.), do not approach it, immediately report the find to the police, and do not allow bystanders to touch the dangerous object or attempt to disarm it.
If there is a threat of an explosion indoors, beware of falling plaster, reinforcement, cabinets, and shelves. Keep away from windows, mirrors, and light fittings. If you are outside, run to the middle of the street, a square, or a vacant lot, i.e. away from buildings and structures, poles and power lines. If you were warned of the threat in advance, before leaving your home or workplace, turn off the electricity and gas. Take the necessary belongings and documents, a supply of food and medicines. If an explosion occurs in a neighbouring building, call the police (housing office, maintenance service) and find out the situation. When evacuating, take your documents and essential items. Move carefully, without touching damaged structures or exposed wires. Act in accordance with the instructions of the officials who have arrived at the scene of the explosion.
If an explosion has occurred in your flat or a neighbouring one, and you are conscious and able to move, try to act. Look and see who among the people near you needs help. If the telephone is working, report what happened by calling "101", "102", "103". Do not try to use the stairs, and even less the lift, to leave the building; they may be damaged (destroyed). You should leave the building only if a fire has started or there is a threat of structural collapse.
If you are trapped by a fallen partition or furniture, try to help yourself and those who will come to your aid; give signals (tap on metal objects, floor slabs) so that you can be heard and located. Do this whenever rescue equipment stops working. If you are injured, give yourself whatever help you can. Make yourself as comfortable as possible, remove sharp, hard and piercing objects, and cover yourself. If a heavy object is pressing on any part of your body, massage it to maintain blood circulation. Wait for rescuers; you will certainly be found.
If a building has been damaged by an explosion, before entering it, you must make sure there is no significant destruction of floor slabs, walls, electricity, gas and water supply lines, as well as no gas leaks or seats of fire.
Accidents on gas and oil pipelines. Gas and oil pipelines belong to pipeline transport and are used to transport highly flammable substances. Accidents on them lead to environmental pollution, the release of petroleum products into rivers, seas and the water table, which can cause the death of animals and plants. In addition, such accidents can be accompanied by explosions and fires, which lead to loss of life. A particularly dangerous situation can arise when gas and oil pipeline mains find themselves in areas of natural (wild) fires.
Municipal gas networks
The following emergency situations can occur in the gas supply systems of populated areas:
As examples of the elimination of cases of gas-air mixture explosions in residential buildings and other structures with the simultaneous occurrence of fires show, such accidents are eliminated within several days. Restoration work continues for months. In this process the residents of such buildings have to be relocated to other housing, and the building has to undergo major repairs. Various services are involved in carrying out the necessary measures to eliminate the consequences of the accident, primarily: fire, medical, public order protection, gas utility and energy services, as well as representatives of local self-government bodies, housing maintenance offices, and others. Construction organisations and organisations that have the necessary equipment are involved in carrying out restoration work.
Hydrodynamic accidents
Hydrodynamic accidents include: breaches of dams, embankments, sluices with the formation of breach waves followed by catastrophic flooding; breach floods; emergency discharge from hydroelectric power station reservoirs due to the threat of a hydraulic structure failure.
The zone of catastrophic flooding is considered to be the territory through which the breach wave passes within 4 hours. All this leads to great material losses, destruction of buildings and structures, and destruction of the natural landscape. And since such events, as a rule, occur unexpectedly (suddenly), they can lead to significant human casualties.
Water supply and sewerage networks
The causes of emergency situations may be:
An accident on a water canal or river can be dangerous, since as a result of the accident the supply of drinking or industrial water to cities, villages and economic facilities may be halted (80-86% of the region's water supply limits are supplied from the canal). In this case:
In the event of an emergency situation in power networks associated with a deep drop in frequency (below 49 hertz), restrictions on power load may be introduced, which will lead to the following canal operating modes:
A reduction in the water supply to the canal or rivers will cause a drop in water level, which will give rise to destructive processes, and restarting it after a lengthy shutdown requires large financial and technical expenditures to bring the canal into working condition.
Sewerage networks
In accidents on sewerage networks with discharges of waste water, a complex situation may develop: domestic and faecal effluent getting into drinking water networks, urban ponds and beaches, and rivers, which in turn will cause epidemic diseases, an unfavourable medical situation, and contamination of the environment. This requires the organisation and provision of all types of medical care to those affected. The scale and structure of sanitary losses can vary and be local in nature. Among the injured, traumatological pathology, neuropsychiatric disorders and complications of somatic diseases requiring emergency medical care are to be expected.
Contamination of water in ponds and rivers will lead to contamination of fish, with subsequent infection of people through consumption of poor-quality fish.
As communal and domestic living conditions of the population deteriorate, along with secondary causes, there will be a tendency towards outbreaks of intestinal infections, viral hepatitis and leptospirosis, and outbreaks of cholera, typhus, and acute respiratory and viral diseases are possible. Long-term data show a rise in diphtheria cases in the region.
There are real preconditions for the emergence of especially dangerous cholera infections due to the constant shedding of the causative agent from the water of open reservoirs used for domestic and drinking needs, including from the Sea of Azov (in the southern coastal districts of the region).
Heat supply networks
The following emergency situations can arise on heat supply networks and in boiler houses during the cold season:
The most dangerous accidents can be those in which fires occur, which will complicate the circumstances of the accident, since this creates a threat not only to people but also destroys equipment, buildings, and the like, and eliminating the consequences of the accident will require considerable material and financial expenditure. Fires can threaten not only the buildings where the fire started, but also those located nearby.
In addition, during the cold season the conditions and timeframes for carrying out work become more difficult due to low temperatures, and on frozen heat supply networks the scale of the accident may continue to increase.
Eliminating the accident requires the involvement of considerable forces and resources, and material resources; the work may be carried out.
Transport accidents can be divided into the following groups:
Road transport accidents.
Our country is saturated with national economy facilities that use hazardous chemical substances and explosive substances in production. Their transportation is carried out by various modes of transport, including road transport. Chlorine and ammonia make up the basis of all hazardous chemical substances.
Road transport is used to carry liquid chlorine across the region to filtration stations, and liquid ammonia to enterprises of the agro-industrial complex.
Accidents involving spills of hazardous chemical substances can occur during their transportation to their destination, both on the region's roads and in city streets, which will inevitably lead to injury of people, animals and plants, and contamination of the area.
All this requires coordinated action by all, without exception, administrations, organisations and enterprises involved in the transportation of dangerous goods by road.
To prevent accidents and disasters and to eliminate their consequences, it is necessary to plan the necessary forces and resources so that they would be ready for immediate use as intended.
The peculiarity of road accidents is that 80% of the injured die within the first 3 hours due to heavy blood loss. According to statistics, road traffic accidents most often occur during rush hour, on holidays, and in the first and last days of vacations. The road is especially dangerous in winter. The winter months account for 60% of all accidents in the year. Rain and fog also complicate road conditions and often become the cause of road traffic accidents (RTA).
If a collision is unavoidable, keep calm. This will allow you to control the car until the last possible moment. Tense all your muscles and do not relax until you come to a complete stop. Do everything you can to avoid a head-on impact: a ditch, a fence, bushes, even a tree are better than a car moving towards you.
Remember that, when hitting a stationary object, an impact on the left or right fender is worse than hitting it with the whole bumper.
If a collision is unavoidable, protect your head. If the car is moving at low speed, press your back into the seat and, tensing all your muscles, brace your arms against the steering wheel. If the speed exceeds 60 km/h and you are not wearing a seatbelt, press your chest against the steering column. If you are in the front passenger seat, cover your head with your arms and fall onto your side, stretching out on the seat. If you are sitting in the back seat, try to drop onto the floor. If there is a child next to you, cover them with your own body.
After the accident work out where in the car and in what position you are, whether the car is on fire, and whether petrol is leaking (especially if it has rolled over). If the doors are jammed, leave the car through the windows, either opening them or breaking them with a heavy object at hand. Once you have got out of the car, move as far away from it as possible - an explosion is possible.
If a car falls into water it may stay afloat for some time. Get out through an open window, since opening the door will make the car start to sink rapidly. When it sinks to the bottom with the windows and doors closed, the air inside the car will last for several minutes. Turn on the headlights (it makes you easier to find), actively ventilate your lungs (deep breaths in and out let you saturate your blood with oxygen "in advance"), and get rid of any unnecessary clothing. Get out of the car once it is half filled with water, otherwise the flow of water entering the cabin will hinder you. If necessary, break the windscreen with a heavy object at hand. Squeeze yourself out, gripping the roof of the car with your hands, and then swim upwards sharply.
If you are involved in a road traffic accident, you should stop immediately and inspect the cars - your own and that of the injured driver (if you are at fault for the accident). If there are casualties, under no circumstances leave them without help. Report the incident by calling "02" or pass the information to the nearest traffic police post through passing drivers. Do not leave the scene of the accident before traffic police officers arrive. Preserve all traces of the incident as far as possible.
All passengers using public transport services
must know and observe the basic safety rules:
- do not board or alight from the vehicle until it has come to a complete stop;
- do not lean against the doors, and do not put your head or arms out of the windows;
- inside a trolleybus or bus, try to hold on to the handrails in case of emergency braking (a reliable point of support is the handrail above your head);
- stand facing the direction of travel, so as to be able to notice danger in advance and manage to react to it in time (from this position, in the event of a collision or braking, you will fall forwards, which is much safer than falling backwards);
- in the event of a collision, if you are unable to stay upright, try to curl up as you fall, cover your head with your hands, and watch where you land.
Umbrellas, walking sticks and other objects with sharp or protruding edges pose a definite hazard in the event of sudden braking. It is unsafe to walk about in a moving vehicle instead of standing while holding on to the handrails, and it is also unsafe to doze off. In these cases a person simply does not have time to react to the danger.
Any public transport, including electric transport, is a fire hazard. For this reason, after a road traffic accident it is advisable to leave the cabin quickly and move 10-15 m away. If the exit doors are jammed or a crowd of people has formed, use the emergency exits. Do not wait for the situation to become critical. Break the windows, using any heavy object at hand for this: a fire extinguisher located in the cabin, a wheel chock, a hard briefcase, etc.; as a last resort, break the glass with a strong kick of your foot into the corner of the window, hanging on with your hands from the ceiling handrails. Before getting out, be sure to clear the window opening of any remaining glass.
If there is a smell of burning, such measures should be considered mandatory, since passengers may not have time to form a queue leading to a working exit. In the event of a fire, city transport burns very quickly. In this case, your nose and mouth should be protected in advance with a scarf, sleeve or other material, moistened with any liquid if possible.
In the event of a fire in the cabin, report it to the driver, open the doors (using the emergency opening mechanism), the emergency exits, or break a window. If there is a fire extinguisher in the cabin, take measures to put out the source of the fire. Get out of the cabin, crouching as you go outside, without touching the walls or metal parts.
In the event of an accident involving damage to a live wire, the safest places in a tram or trolleybus are the seats. In this case it is best to lift your feet off the floor, and it is best not to touch the walls or handrails. You should get off electric transport by jumping, with both feet forward at the same time, without touching the body of the vehicle, so as not to close the electrical circuit with your own body.
Accident-free operation of urban electric transport is ensured by timely technical maintenance of rolling stock, compliance with operating rules and traffic regulations, the proper condition of the contact network, and constant, stable power supply.
To prevent and eliminate the consequences of emergency situations related to accidents on urban electric transport, specialised forces and resources have been created in the towns of the region, including 10 emergency technical assistance teams and 5 accident recovery teams (for repairing tram tracks). These forces are ready to work within 10 minutes if they are on duty shift, and within up to 3 hours if the accident occurs outside working hours.
Railway transport accidents – this primarily concerns accidents involving freight and passenger trains, which can be accompanied by large numbers of casualties. The main causes of accidents and disasters on railway transport can be: faulty track and rolling stock; faulty signalling, interlocking and blocking equipment; dispatcher errors; and inattention and errors by train drivers. Emergency situations can be most dangerous when transporting radioactive and hazardous chemical substances. A complex situation can arise as a result of an accident within the boundaries of a railway station, since residential buildings with a high population density are very often located near it, a large number of wagons with various kinds of cargo are concentrated on the territory of the station itself, and there are large numbers of people in trains, on platforms, in the station building and around it. All this creates a significant threat to people in the event of explosions and contamination of the air and terrain with radioactive and chemical substances.
Accidents on sea and river transport – the main causes of vessel loss are: running aground on reefs (shoals); collision with other vessels or with bridge supports; capsizing; fires; leakage of hazardous chemical substances; violation of operating standards and safety rules; erroneous functional actions by the crew, and others. A complex situation can arise in a rapidly developing emergency situation, especially on the open sea. A disaster can occur in a port (harbour), while a vessel is moving along a river, or in a sea or lake area. According to statistics, around 8000 vessels are involved in accidents in world maritime transport every year, of which around 200 sink, with more than 2000 people killed and around 6000 exposed to direct danger to life.
When an emergency situation arises on air transport in flight, the crew may decide to make an emergency landing. In preparing for it, you must immediately clear the aisles and take your seats, with the seat backs put in an upright position. In addition, you need to remove glasses and dentures, take sharp objects (pens, knives, lighters) out of your inside pockets, remove high-heeled shoes, loosen your tie and unbutton your collar. After that, place soft items on your lap to protect your head and body, and fasten and tighten your seatbelt firmly. At the flight attendant's command "Brace for landing!" you should lean forward, cover your head with soft items and rest it on your arms, wrapping them around your knees. You need to remain in this position until the plane comes to a complete stop.
After the plane has stopped, unfasten your seatbelt and prepare for evacuation. All the main and reserve doors, as well as the emergency exits, usually located on the left and right sides of the fuselage, are used for the emergency evacuation of passengers and crew from the plane. The exits for passengers, the approaches to them and the opening mechanisms are conspicuously marked to make them easier to find. All the signs are illuminated from within, independent of the main lighting system. The design of the emergency hatches and locks with handles is made simple, conspicuous, and does not require much effort to open. Instructions for opening them are printed on the doors (hatches). At the locations of the emergency exits onto the wing, the aisles between the seats are wider than elsewhere, and do not hinder the opening of the hatches or the exit of passengers.
When leaving your seat, do not take with you any baggage brought on board as hand luggage. This is dictated by safety measures, since it is quite likely that some items in your bag have sharp corners and edges. This could cause damage to the inflatable escape slide and cause it to deflate, which in turn would lead to injuries, and possibly to the deaths of passengers waiting their turn to evacuate.
When leaving the plane through an exit with the slide deployed and inflated, you need to jump onto it without stopping, rather than sitting down on the edge and then sliding down. Only by jumping can the speed of evacuation be increased.
Knowledge check:
Answer the questions:
a) emergency situations of an ecological nature;
b) emergency situations of a natural nature;
c) emergency situations of a technogenic (man-made) nature;
d) natural disasters.
a) arising from technical causes, as well as from random external effects at an industrial enterprise;
b) connected with the threat of release of a hazardous substance;
c) resulting in loss of human life and damage.
a) the presence of human casualties, significant damage;
b) the effect of damaging factors on people;
c) the effect on the natural environment.
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