XIV. Give a short summary of the text

XV. Translate the following microtext

Sprinkler Systems

A sprinkler system is an integrated system of underground and overhead piping, designed in accordance with fire protection engineering standards, and connected to one or more automatic water supplies. The system is usually activated by heat from a fire, and the sprinkler heads then discharge water over the fire area. Sprinkler systems are nearly 100 percent effective. Many sprinkler systems are supervised electrically from a central station, and alarms are transmitted to a fire department whenever the sprinklers operate or when a valve in the sprinkler system closes for any reason. If a fire-fighting unit arriving at a fire finds that the sprinkler system is not receiving sufficient water and pressure, a pumper is connected to the sprinkler system to supply additional water.

Many high-rise or other large buildings have an internal system of water mains (standpipes) connected to fire-hose stations. Trained occupants or employees of the building management operate the hoses until the fire department arrives. Fire fighters can also connect their hoses to outlets near the fire.

XVI. Learn and retell the text:

Portable Fire Extinguishers

1. The sooner a fire is detected, the easier it is to put out.

2. Most home fires occur at night when the family is asleep.

3. Fire departments advise people to install smoke detectors in their homes. 4. Smoke detectors sound an alarm if a small amount of smoke enters their sensors.

5. The most commonly used fire extinguishing devices are portable fire extinguishers.

6. Portable fire extinguishers are an item of firefighting equipment containing a fire extinguishing medium.

7. Their advantages are their simplicity in operation and design.

8. Their disadvantages are that they must be operated manually.

9. Portable fire extinguishers can be classified according to the extinguishing agent they contain and according to their method of operation.

10. According to the extinguishing agent portable fire extinguishers can be divided into 5 categories.

11. A fire extinguisher consists of several basic components.

12. The first is a container with extinguishing agent. In the small, first-aid water fire extinguishers, a propellant must be provided.

13. Usually this is a carbon dioxide.

ADDITIONAL MATERIAL

TEXT 1

Early Detection Alarm Systems

The five principal types of fire detectors in common use are:

1. Electronic combustion gas detector. This device detects the combustion gases at an early stage of a fire, often long before the smoke would be noticed. Such a detector can usually monitor in excess of 500 ft² (50 m² or more) of floor area and is preferred in occupancies where life safety is critical.

2. Radiant-emission detector. Such detector responds to infrared or ultraviolet radiation. In some cases, this detector is designed to respond to rapid fluctuation in the radiation, the rate of fluctuation being chosen to correspond approximately to the flicker rate of fires but to exclude the background radiation from other sources. Some versions have a response delay to further screen out background signals. Such a detector can monitor as much as 1,000 m² of floor area of its field of view.

3. Light-scattering (or refracting) detector. This device appears in various versions, each employing a different principle. One commonly used detector of this type is based on the scattering of light by smoke particles. A new device uses the reflection of a multiply reflected laser beam to detect convection cells produced by a fire. The smoke detectors are relatively slow, and they sample only small volumes of room area, but the laser-beam approach appears to suffer neither disadvantage.

4. Fixed-temperature detectors. This detector triggers an alarm upon reaching a present temperature. Typical versions respond at a temperature level of 70^oC. They are also available in temperatures ranging from as low as 50^oC to as high as 130^oC. The fixed-temperature detector ordinarily will protect an area of 10 m². Relatively sluggish in response, this type of detector is unsuited in protection of unoccupied property, such as in automatic sprinkler systems for warehouses and the like.

5. Rate of temperature rise detector. Such a type responds to a quick rise in room temperature. A typical version responds when the rate of rise exceeds about 0,2C/S; first, however, the temperature must exceed a certain fixed value. A rate of temperature detector usually monitors about 20 m² of floor area.

TEXT 2

Fire Trucks

Many fire departments have several different types of fire trucks. The main types are (1) engines,(2) ladder trucks, and (3) rescue trucks.

Engines have a large pump that takes water from a fire hydrant or other sources. Engines carry several sizes of hoses and nozzles. Engines used for fighting grass or brush carry a tank of water and such tools as shovels and rakes.

Ladder trucks. There are two kinds of ladder trucks - aerial ladder trucks and elevating platform trucks. An aerial ladder truck has a metal extension ladder mounted on a turntable. The ladder can be raised as high as 30 meters, or about eight stories. An elevating-platform truck has a cagelike platform that can hold several people. The platform is attached to a lifting device that is mounted on a turntable. Ladder trucks are equipped with portable ladders of various types and sizes. They also carry entry tools which firefighters use to enter into a building and to ventilate it to let out smoke. Common forcible entry tools include axes, power saws, and sledge hammers.

Rescue trucks carry additional equipment for unusual rescues. They have such tools as oxyacetylene torches, for cutting through metal, and hydraulic jacks, for lifting heavy objects. Rescue trucks may also carry other hydraulic tools to free people trapped in automobiles after an accident, to rescue people from water or high places. They also carry medical supplies and equipment.

Special fire vehicles include airport crash trucks and hazardous materials trucks. Airports crash trucks are engines that spray foam or dry chemicals on burning aircraft. Water is inefficient against many aircraft fires, such as those that involve jet fuel, gasoline, or certain metals. Hazardous-materials units carry tools to stop gas leaks, and supplies to absorb or clean up spills of dangerous liquids or solids. These trucks also have equipment to prevent the spread of liquid spills that can contaminate the environment. Hazardous materials include pesticides, fertilizers, and other chemicals as well as gasoline, natural gas, and other fuels. Many hazardous-materials emergencies involve truck or train wrecks in which a dangerous substance is accidentally spilled.

TEXT 3

A SHIPBOARD FIRE DETECTION SYSTEM

A fire detector is a device that gives a warning when fire occurs in the area protected by the device. The fire detection system, including one or more detectors, relays the alarm to those endangered by the fire and or.those responsible for firefighting operations. Ashore, a fire detector sounds an alarm so that occupants can leave a burning building promptly, and the fire department can be summoned. The detection system can also activate fire extinguishing equipment. At sea, however, there are no fire escapes, and no professional fire department to call. A shipboard fire detection system alerts the ship's crew, who must cope with the emergency using the resources they have on board.

Early discovery of fire is essential. The fire must be confined, controlled and extinguished in an early stages, before it gets out of control and endangers the ship and the lives of those on board. A well designed fire detection system, properly installed and maintained, and understood by those who must interpret its signals, will give the early warning of a fire, in the area it protects and its location.

Fire detection systems on board a ship are so arranged that in case of a fire, both a visible and audible alarm are received in the pilothouse or fire control station (normally the bridge) and for vessels of over 150 feet in length there should be an audible alarm in the engine room. The receiving equipment indicates both the occurence of a fire and its location aboard the ship. Consoles are located on the bridge and in the CO₂ room. The CO₂ room is the space that contains the fire extinguishing mechanisms. Only a bell is required in the engine room to alert the engineer to an emergency outside the machinery space.

Upon hearing a fire alarm, the watch officer on the bridge sounds the general alarm to call the crew to their fire and emergency stations as listed on the station bill. However, in all cases the master must be alerted immediately and the cause of the alarm must be investigated. If the alarm was for an actual fire action should be taken to confine, control and extinguish it. The crew must respond as per the station bill, under the direction of the master. If it was a false alarm, its cause should be investigated and corrected, if possible. In either event the fire detection system should be checked and the system put back in service after the proper action is taken. Losses have occurred when a system was not reactivated after an alarm, and hence did not send a signal when a subsequent real fire or reflash occurred.

The types of fire protective systems approved for use aboard ship include the following:

1. Automatic fire detection systems.

2. Manual fire alarm systems.

3. Smoke detection systems.

4. Watchmen's supervisory systems.

5. Combinations of the above.

Поиск по сайту: