canister manually or if there is a shortage of available
REMOVING A USED CANISTER.-- When
canisters. Under no circumstances should you save the
you remove a hot canister, you need to protect your
chlorate candle to use for an emergency exit of the
hands with approved protective gloves. Once the
canister has been used, remove the facepiece and put it
space. Such practice is dangerous, and the candles have
over your head in the standby position. Then release
been known to misfire.
the bail from the operation position and swing it down
When manually starting the canister, you should
to the load and standby positions. Next spread your feet
be in a clean atmosphere and must adhere to the
apart and lean the upper part of your body slightly
forward. To release the used canister, pull the canister
Step 1. Work one finger under the edge of your
release strap (fig. 5-24). The canister will drop out of
facepiece, stretching the mask slightly to break the seal.
the apparatus (fig. 5-25). Drop the canister ONLY on a
clean, dry deck.
Step 2. Inhale while grasping and squeezing both
breathing tubes with your other hand. This will allow
you to draw external air from outside the facepiece.
Step 3. Release the breathing tubes, remove your
finger to reseal the mask, and exhale into the facepiece.
Step 4. Continue this cycle until your breathing
bag is fully inflated. Exhaust the air in the breathing bag
by exerting pressure on the right-hand side until the bag
on the right is deflated. In this process, your moist
breath passes through the canister to start the chemical
reaction. One filling of the bag is not usually sufficient
Figure 5-24. Releasing the canister.
to activate the canister fully.
Step 5. Repeat steps 1 through 4 to reinflate and
deflate the breathing bag at least five times. Now,
You must be careful when removing used
without gloves, cautiously feel the bottom of the
canisters from the OBA. The canisters are hot,
canister. If the entire bottom of the canister is warm,
and the chemicals inside of the canister are
oxygen is being generated. The apparatus is then ready
similar to caustic soda and can cause serious
for setting the timer and for the operational check. If the
chemical burns if they get on your skin. Also,
canister is not warm, repeat steps 1 through 4. In cooler
the chemicals will cause a violent explosion if
temperatures, several cycles of inflation and deflation of
they come into contact with a petroleum-based
the bag may be required to start oxygen production.
SETTING THE TIMER.-- To set the timer,
grasp the knob on the timer. Turn the knob clockwise to
60 minutes, and then turn it counterclockwise to
30 minutes. By setting the timer to 60 first, you fully
wind the alarm bell spring. When 30 minutes have
expired, the warning bell will sound continuously for
10 or more seconds. When you have set the timer, you
are ready to enter a hazardous atmosphere.
REMOVING AN UNUSED CANISTER.-- If
the copper-foil seal of the canister has not been
punctured, remove the canister by placing one hand on
the bottom of the canister and pulling the canister
Figure 5-25. Dropping the canister.
releasing strap. You do not need to wear gloves in this
situation. The handle must also be in the load and
DISPOSAL OF USED CANISTERS.-- You
standby positions. Once the canister is removed,
must dispose of an OBA quick-starting canister as soon
protect the copper-foil seal by installing an aluminum
as possible after it has been used or when the
cap. These caps are designed for this purpose and are
copper-foil seal has been punctured. If your ship is
maintained in repair lockers.
more than 25 nautical miles from shore, the OOD may