Once the cylinder valve has been turned on, it
provides a continuous air supply to the system regulator
via the high-pressure hose. The pressure is reduced by
the regulator for use by the wearer, and the low-pressure
hose carries the breathable air into the facepiece. As a
safety feature, these are positive pressure style
regulators, which means that the air supply to the mask
is just above any demand requirements eliminating any
possibility of toxic fumes from entering the wearer’s
mask.
The time each cylinder lasts will be determined by a
number of factors. The main factors will be the physical
condition and size of the wearer and the work to be
done. Generally, each bottle will last approximately 30
minutes from the time it is activated.
REVIEW 5 QUESTIONS
Q1. How many minutes of air is the EEBD designed
to provide?
Q2. Why should you stay away from open flames
when you first remove an EEBD?
Q3. What should you listen for when donning an
EEBD?
Q4. What device is worn by engineering watch
standers?
Q5. What is the effective time of an OBA?
Q6. When do you pull the cotter pin on an OBA
canister?
FIREFIGHTING
Learning Objectives: When you finish this chapter,
you will be able to—
Recognize the properties of a fire triangle and
fire tetrahedron.
I d e n t i f y t h e c o n d i t i o n s n e c e s s a r y f o r
spontaneous combustion.
Identify the types of heat transfer.
Fire is a constant threat aboard ship. All possible
measures must be taken to prevent a fire, or if one is
started, to extinguish it quickly. Fires may start from
s eve r a l
c a u s e s — s p o n t a n e o u s
c o m bu s t i o n ,
carelessness, hits by enemy shells, or collision. If the
fire is not controlled quickly, it may cause more damage
than the initial casualty and could cause the loss of the
ship.
FIRE AND FIREFIGHTING
You cannot win against a fire. You can fight the fire
and you can hold down its damage; but some property
will be destroyed and, all too often, people will be
injured or killed. Time is always lost, productive work is
stopped, and additional effort and materials are required
to make repairs and to clean up the mess.
The objective of fire prevention, therefore, is to
prevent fires from starting. Fire prevention is an
all-hands, all-day, all-night, heads-up effort. A cigarette
tossed in the wrong direction can cause as much damage
as an enemy bomb. An oily wiping rag or a sparking tool
can be as dangerous as an open flame in a gasoline
depot.
Each ship is required to institute and maintain a fire
prevention program. Your part in the fire prevention
program is as follows:
Ensure that all gear is stowed properly.
12-18
Student Notes:
