NSTM 555 - Firefighting

Question 1

What are the components of the Fire Tetrahedron?

Answer 1

Oxygen, Heat, Fuel, Chemical Reaction

Question 2

What is a Class “A” fire?

Answer 2

Combustible materials that produce ash - wood, cloth, paper, etc

Question 3

What is the primary and secondary agents for class A fires

Answer 3

Water in straight or fog patterns, or AFFF for deep seated fires

Question 4

What are Class “B” fires?

Answer 4

Fuel, liquid, flammable oils and fluids, and flammable gases

Question 5

What are the primary agents to combat a class “B” fire?

Answer 5

AFFF, Halon, Water mist

Question 6

What is the most important step to combating a Gas “B” fire?

Answer 6

Securing the source of the leak/gas

Question 7

What is a class “C” fire?

Answer 7

Electrical fire - once power is secured it becomes an “A”

Question 8

What are the primary agents to combat a “C” fire?

Answer 8

CO2, Halon, Water spray

Question 9

Why should PKP only be a last resort for “C” fires?

Answer 9

It is highly corrosive

Question 10

What is a class “D” fire?

Answer 10

Combustible metals such as magnesium and titanium

Question 11

What is the primary agents for a “D” fire?

Answer 11

Water, used in a fog from a safe distance as there may be small explosions when applied

Question 12

How does water put out a fire?

Answer 12

Heat is removed in the form of steam, providing a cooling effect

Question 13

Describe the use of a straight stream water pattern

Answer 13

Aimed from a distance at the base of a fire, used to break up the burning material and apply cooling at source of heat

Question 14

What are the hazards of using a straight stream water pattern?

Answer 14

Can cause flooding below decks due to increased flow, more electrically conducive - don’t use on electrical fires

Question 15

Why are fog patterns more effective than straight streams?

Answer 15

More effective cooling and heat absorption, and provides protection to the firefighters

Question 16

What types of fuel is water effective at combating fires in?

Answer 16

High flashpoint fuels (over 140 F) such as F-76

Question 17

How do you employ water as an agent in a “B” fire?

Answer 17

Use narrow angle fog pattern to the leading edge of the flames in a sweeping pattern

Question 18

What is the Water to AFFF ratio?

Answer 18

94:6

Question 19

What are three advantages to using AFFF?

Answer 19

1. Prevents fuel vapors from escaping
2. Removes Oxygen from the fire
3. Provides cooling effect

Question 20

Is AFFF or Water the better agent for “A” fires?

Answer 20

AFFF

Question 21

Discharge of AFFF to the sea is only allowed at what distance from shore?

Answer 21

12 NM

Question 22

How does CO2 put out fires?

Answer 22

It is 1.5 times heavier than air, so it smothers the fire and removes Oxygen

Question 23

How does Halon 1301 extinguish fires?

Answer 23

Chemically inhibits the fire

Question 24

What should happen upon inadvertent activation of Halon?

Answer 24

Evacuate spaces

Question 25

What is PKP primarily used for?

Answer 25

Class "B" Fires (smaller ones)

Question 26

How does PKP extinguish a fire?

Answer 26

It inhibits the combustion chain - it does not have a cooling effect

Question 27

What ship class is the Water Mist system found on and why?

Answer 27

LPD-17 class. It is a replacement for Halon since Halon is an Ozone Depleting Substance

Question 28

What PSI is the water mist system deployed at?

Answer 28

1000 PSI

Question 29

Advantages to Water mist over Halon?

Answer 29

No need for 30/60 sec delay time, non-ozone depleting, Non-toxic to personnel

Question 30

When is HFP used in place of Water Mist?

Answer 30

On newer class ships in unmanned spaces

Question 31

How is AFFF activated at each hosereel?

Answer 31

There is an electrical pushbutton that activates the system

Question 32

How is AFFF turned off from a hosereel?

Answer 32

There is no off button, the flow can be turned off at the nozzle

Question 33

What color boxes are AFFF Sprinkler activation switches contained in?

Answer 33

Red/Green striped boxes

Question 34

If a major oil leak is detected, what immediate actions can reduce the possibility of a fire?

Answer 34

Secure the oil source and cover surfaces with AFFF

Question 35

If you cannot stop the oil leak, what is another action that can help reduce the possibility of ignition?

Answer 35

Deflect the oil away from hot surfaces

Question 36

What types of fire prevention systems are installed in Gas Turbine and Diesel Engine Enclosures?

Answer 36

Halon, HFP, and CO2