Unit 3. Extinguishing a fire without water.

Asphyxiating a fire. Tactical ventilation.

Useful vocabulary

• desirable/undesirable – желательный/нежелательный

• poisonous gases – ядовитые/отравляющие газы

• to float – плавать/держаться на поверхности

• a layer – слой

• to avoid – избегать

• a conductor - проводник

• fire retardant – огнеупорный

• a fan - вентилятор

• an isolation of a fire – изоляция огня

• trapped occupants – захваченные/заблокированные жители

• to predict – предсказывать/прогнозировать

• a dead end – тупик

Task I. Read the text

There are some situations when the use of water is undesirable, for example:

• some chemical products react with water and produce poisonous gases, or even burn in contact with water;

• some products float on water, e.g., hydrocarbon (gasoline, oil, alcohol, etc.); a burning layer can then spread;

• in case of a pressurized gas tank, it is necessary to avoid heat shocks that may damage the tank;

• electrical fires where water would act as a conductor.

In such cases fire fighters have to asphyxiate the fire. This can be done in different ways:

• some chemical products react with the fuel and stop the combustion;

• a layer of water-based fire retardant foam is projected on the product by the fire hose, to keep the oxygen in air separated from the fuel.

• carbon dioxide.

One of the main risks of a fire is the smoke: it carries heat and poisonous gases, and obscures vision. In the case of a fire in a closed location (building), two different strategies must be used: isolation of the fire, or positive pressure ventilation.

Paul Grimwood introduced the concept of tactical ventilation. Ventilation affects life safety, fire extinguishment, and property conservation. First, it pulls fire away from trapped occupants when properly used. It may also “limit” fire spread by channeling fire toward nearby openings and allows fire fighters to safely attack the fire as well as limit smoke, heat, and water damage.

Positive pressure ventilation (PPV) consists of using a fan to create excess pressure in a part of the building; this pressure will push the smoke and the heat away, and thus secure the rescue and fire fighting operations. It is necessary to have an exit for the smoke, to know the building very well to predict where the smoke will go, and to ensure that the doors remain open. The main risk of this method is that it may activate the fire, or even create a flashover, e.g., if the smoke and the heat accumulate in a dead end.

Hydraulic ventilation is the process of directing a stream from the inside of a structure out the window using a fog pattern. This effectively will pull smoke out of room. Smoke ejectors may also be used for this purpose.

Task II. Define the main idea of the text

1. Water mustn’t be used for fire extinguishment in certain situations.

2. Asphyxiation a fire is done by chemical products mostly.

3. There are several variants of tactical ventilation used in firefighting.

Task III. Say if the statements are

1. Smoke is a great risk for several reasons

a. true b. false c. no such information in the text

2. Tactical ventilation is a risky method

a. true b. false c. no such information in the text

Task II. Answer the following questions

1. What are the situations that don’t allow one to use water for fire extinguishment?

2. Which means are used to asphyxiate a fire?

3. Who is Paul Grimwood?

4. What are the positive aspects of tactical ventilation?

5. Why positive pressure ventilation can be dangerous?

6. What is hydraulic ventilation?

Task III. Fill in the gaps to make the statements correct

1. Some chemical products can … even in contact with water.

2. Heat … may … pressurized gas tanks.

3. If a fire takes place in a closed …, … of the fire or positive pressure ventilation must be used.

4. Ventilation pulls fire away from trapped … and allows … to safely … the fire.

5. It’s good when firefighters know … very well, they can … where the smoke will ….

6. If the smoke and the heat accumulate in the …, a … can take place.

7. Smoke ejectors may be used for the … of pulling smoke out of the room.

Task IV. Guess the words using the definition

1. p … (adj.)- containing poison or producing poison.

2. p … (v.) – to say that something will happen in future.

3. i …(n.) – the act of separating things from others on purpose.

4. e … (n.) – a door or space through which you can leave a place.

5. a … (v). – to gradually increase in number or amount of smth.

Choose one word from the text and write the definition for it. Let the class guess it 

Task V. Make up correct word combinations

• oil a. a dangerous fire

• to asphyxiate b. and heat away

• foam is projected c. by the fire hose

• heavy smoke d. floats on water

• to limit e. to create pressure

• a fan is used f. fire spread

• pressure pushes smoke g. obscures vision

Task VI. Grammar focus. Revision of modal verbs: find the examples in the text and explain their use

Task VII. Translate the following sentences with modals and make them passive if possible

1. Firemen have to wear protective clothing when working.

2. Different methods may be used for fire extinguishment.

3. One must be careful with gas and matches.

4. My friend may become my colleague.

5. Water-based fire retardant foam can keep the oxygen separated from the fuel.

6. A fan is to create excess pressure that will secure the rescue and fire fighting operations.

7. We had to call to emergency services as the situation was really serious.

8. A conductor can carry an electric charge.

9. Finding an emergency exit in this building may be difficult as there is no construction plan on the walls.

10. Could you tell us the way to the centre of the city?

Task IX. Insert the correct modal verb

1. She eats too much. She … stop.

2. I … to go to work by bus every day.

3. Children … (not) watch TV so much.

4. I … go on holiday soon.

5. My friend is very tired. He … (not) walk.

6. … you speak English?

7. It’s a fantastic film. You … go and see it.

8. We … decide now. We have no time for thinking.

9. They … have a party next weekend.

10. … we have a coffee break?