that no areas are missed. All cableways, areas beneath
DESMOKING
deckplates, and overheads are examined to ensure no
Active desmoking is the process of removing smoke
hangfires are missed. At various times, the team leader
and heat from the buffer zone prior to extinguishing a
will make reports detailing percentage of overhaul. If
fire. This action aids fire-fighting efforts, and helps
hangfires are found, they are extinguished. It is
prevent the spread of smoke throughout the ship.
sometimes necessary to use overhaul equipment to pull
Desmoking may be accomplished using ventilation fans
smoldering or burning material (such as lagging) from
in adjacent compartments or with portable fans. There
an overhead or bulkhead in order to extinguish it.
will be some smoke in surrounding areas; smoke
boundaries will help slow the spread of smoke. This
REVIEW QUESTIONS
type of desmoking should not be confused with the
desmoking process of the affected compartment after
the fire has been overhauled.
Q14.
Which member of the attack team controls
the movement of hose teams while inside a
When a class BRAVO fire has been extinguished,
space that is on fire?
combustible gases may be present. Operating electric
controllers to start ventilation fans may ignite these
1.
On-scene leader
gases. Desmoking with installed ventilation can
2.
Fire marshal
proceed with minimal risk once specific conditions are
3.
Nozzleman
met. These conditions include the following:
The fire is extinguished and overhauled.
4.
Attack team leader
The AFFF bilge sprinkling has been operated.
Q15.
Which of the following conditions is NOT a
symptom of heat stroke?
The source of the fuel for the fire is secured.
1.
No sweating with skin hot and dry
The space has been allowed to cool.
2.
A weak pulse
All fuel has been washed to the bilges.
3.
Constriction of the pupils of the eyes
No damage has been sustained to the electrical
4.
Victim is unconscious
distribution system.
Q16.
What is the purpose of a reflash watch?
Desmoking should begin once the compartment
1.
To overhaul the compartment
has cooled sufficiently so there is no danger from
reignition. Circuit breakers that have tripped should
2.
To ensure that no new fire breaks out
not be reset until qualified personnel can make a
3.
To extinguish hangfires
damage assessment. Examine the electrical
distribution system, and if possible, reestablish power
4.
to the installed ventilation fans. If the fans are fully
operational, run them on high speed for a minimum of
15 minutes to remove smoke and toxic gases. If the
DESMOKING AND ATMOSPHERIC
installed system is partially operational or inoperative,
TESTING
desmoking will take longer, but can be accomplished
by using portable blowers, or by providing a positive
Learning Objective: Recall the procedures used once a
ventilation from adjacent spaces. On ships without
Halon or AFFF bilge sprinkling, the safest method of
fire is extinguished to prepare the compartment for
desmoking is to exhaust the compartment with
remanning.
portable fans, or to provide a positive ventilation
Once a fire is extinguished, specific actions must
pressure from adjacent compartments.
be taken to return the compartment or space damaged
ATMOSPHERIC TESTING
by the fire to a condition suitable for remanning. These
a c t i o n s i n c l u d e t h e f o l l ow i n g : d e s m o k i n g ,
Atmospheric tests are always conducted after
atmospheric testing, dewatering, and a thorough
desmoking is complete, because combustible gas
follow-up inspection.
indicators will not operate reliably in a Halon
7-15