grant permission to dispose of the canister overboard.
OBA Equipment Stowage
Once permission has been granted, ensure that the
Before the OBA is stowed, the facepiece should be
canister cap is removed and the copper-foil seal is fully
protected to prevent scratches and abrasions. All OBA
punctured. This will allow water to enter the canister.
equipment and canisters must be stored in a cool, dry
DO NOT puncture holes in the bottom or sides of the
place. The life of an OBA will be lengthened if it is
canister. Make sure there is no oil in the water. Then
stored under these conditions. The term cool denotes
throw the canister overboard. If oil gets inside of the
temperatures ranging from above freezing to 110°F
canister, a violent explosion will occur. If you are
(43°C) when storage is out of direct sunlight. The term
within 25 nautical miles of shore, do not throw the
canister overboard. Instead, let it cool down for at least
does not come in contact with the equipment.
30 minutes. (If a canister was not used but the
The OBA is normally stowed in repair lockers or in
copper-foil seal has been punctured, place the canister
OBA lockers. These lockers have provisions for
in a clean bucket. Light off the canister and let it set for
stowing the OBA in a flat position. You should ensure
15 minutes to cool.) When the canister is cool enough
that the facepiece is properly protected to prevent
to handle, place a new metal cap on the neck to cover
scratching or scarring of the lens. The flash hood may
the punctured copper-foil seal. Then double wrap the
be used to protect the lens of the facepiece. The
canister in a poly bag. The wrapped canister should
canisters should be stowed with the concave side
then be stored in a dry, oil-free area until it can be
down. Additional information on cleaning, inspecting,
disposed of at sea or turned over to a shore facility for
and testing of the type A-4 OBA can be found in the
disposal. When the ship is in port, contact the
Naval Ships' Technical Manual (NSTM), chapter 079,
department ashore that is responsible for hazardous
volume 2, and the appropriate PMS.
waste. Make arrangements with that department to turn
all canisters over to them for disposal.
REMOVING THE OBA.-- The steps of the
procedure for removing the OBA are as follows:
The self-contained breathing apparatus (SCBA) is
now being phased aboard ship as a replacement for the
Step 1. Remove the facepiece by releasing the
OBA. The SCBA is designed to be used for fire fighting
head straps at the buckles with your fingertips before
and is entirely self-contained, allowing the wearer to
pulling the headpiece off. If the canister is still in the
breathe independently of the outside atmosphere. It
OBA, place the facepiece over your head in the standby
provides clean breathable air from a tank carried on the
position and remove the canister. NEVER remove the
back that allows the wearer to enter spaces in much the
OBA with a canister in place.
same manner as an OBA.
Step 2. If the facepiece is in standby position, you
The SCBA operates using a demand-pressure
should remove it and let it hang in front of the OBA.
system. When the wearer inhales normally, the
Loosen the waist strap; then unhook it.
regulator opens, allowing air to flow into the mask.
When the wearer exhales, a simple one-way valve
Step 4. Loosen the shoulder straps and unhook
(known as an exhalation valve) vents the exhaled air
the harness at the upper corners of the breastplate
assembly. Grasp the facepiece and operating handle
atmosphere to enter the mask. This operation is also
with one hand and the shoulder harness (preferably at
known as an open-circuit system.
the D-ring connector) with your other hand. Lift the
OBA over your head.
There are several different models of SCBA in use,
If the OBA is wet or moist, wipe it down.
both aboard ship and at shore facilities. All SCBAs
have four basic component assemblies and operate in a
Step 6. Always clean the outside body of the
similar manner. The assemblies are as follows:
OBA after each use with a mild solution of soap and
Step 7. Disinfect the inside of the facepiece. Mix
Air tank assembly
the disinfectant according to the manufacturer's
3. Regulator assembly (including low-pressure
instructions, as stated on the container label. Use a
alarm and high-pressure hose)
sponge that is moist, but not dripping, with the