positive contact to ground to avoid unwanted
discharge while operating around explosive
Learning Objective: To recall characteristics of
Portable Electric Desmoking Fans
desmoking fans and blowers and other miscellaneous
pieces of damage control gear.
The medium capacity fan is a portable electric fan
There are other miscellaneous pieces of portable
designed to be used by damage control personnel for
damage control equipment that you need to be familiar
rapidly desmoking compartments in areas where
with. These include various fans and blowers and battle
exhaust ducting is not needed. It produces a tight spiral
of air or smoke to prevent recirculation into the area
PORTABLE FANS AND BLOWERS
The portable desmoking fan should be inspected
Different types of fans and blowers are available
for damage before use. Careful inspection of the
for desmoking, and each has different advantages.
electrical cord is necessary to prevent shock hazards,
Some are electric motor-driven and are not to be used
and the tamper seal on the electric motor must be
in explosive environments. Other blowers are powered
intact. If this seal is broken, the fan must not be used in
by the firemain; these require that the firemain be
any explosive environments. Ensure that the screen
available and that hoses be rigged to supply them.
guards are in place before operation.
These fans require cleaning, inspection, and
maintenance to ensure their reliability, and this may be
The portable electric desmoking fan operates
your responsibility. Additionally, you may be involved
using 115 volts ac; simply plug it in and turn it on.
in repairs and/or component replacement and will use
Damage control plates and your Main Space Fire
PMS and the manufacturer's technical manuals to
Doctrine will assist you in determining the most
ensure quality maintenance.
efficient desmoking methods. Additional guidance
may be found in NSTM, chapter 555, volume 1.
Fans or blowers are often used to recirculate or
remove large volumes of air. Electric "box" fans are
Cleaning, inspection, and testing of these fans
convenient and easy to rig but pose risks when
must be accomplished according to PMS and the
operating in (or removing) explosive atmospheres.
manufacturer's technical manual.
Additionally, these fans require that power be available
for operation. Water-driven blowers do not pose this
threat (as long as they are properly grounded), but
other considerations do apply. The firemain is the
Battle lanterns are provided throughout the ship
motive force for this blower and must be rigged to
for emergency lighting whenever normal lighting is
supply it, as well as a discharge hose.
unavailable. The two types of battle lanterns are relay
and portable lanterns and they are mounted in
s t r a t eg i c l o c a t i o n s t o i l l u m i n a t e p a s s a g ewa y s ,
damage control equipment, ladders, and scuttles.
The portable RamfanTM is one of the primary fans
Battle lanterns are damage control equipment, and the
used aboard ships today for desmoking or introducing
damage control petty officer uses PMS to repair and
ventilation into a compartment. The firemain or a
P-100 pump supplies the power for the RamfanTM
through a 1 1/2-inch hose connection. A water turbine
operates the fan blades, which may rotate in excess of
10,000 rpm (depending on firemain pressure). The
Relay lanterns are installed throughout the ship to
RamfanTM is compact (18 inches in diameter) and
weighs under 35 pounds, allowing easy transport.
Battle lanterns use standard-issue 6-volt batteries and
are periodically checked to ensure their reliability. The
electrical relays in these lanterns turn the lantern on
whenever the normal lighting circuits are de-energized.
Exhausting gases through duct can create
a static electric charge. It is important to ensure
These have the following uses and applications: