Leopard Catamarans 40 - Page 57

2-11 FireFighting | 49
Therefore, the rst concern is to SHUT
OFF THE SUPPLY OF GAS. If it is not
possible to shut off the gas supply, keep
thebulkheadsandoverheadwetwithwater
tokeepthemcoolandbelowthekindling
point of their construction materials and
thus prevent the spread of the re to
adjacent combustibles. Let the Gas burn
itselfout.Sometimes,ifitisnotpossibleto
shut off the gas supply valve, it may be
possibletothrowthecylinderoverboard.If
reimpingesuponcylinders,drenchthem
with water to forestall opening of safety
reliefdevices.
Disconnection of Electrical Power:
In the event of a re on board, it is
recommendedthatallsourcesofelectrical
power be disconnected in order to avoid
occurrenceofaClass"C"re.
Dry Chemical:
Dry chemical is a generic name for a
number of extinguishing agents. Sodium,
potassium and urea potassium
bicarbonates,and potassium chlorideare
effectiveforClass"B"andClass"C"res.
Ammoniumphosphateisusedasamulti-
purpose dry chemical and is effective for
Class"A","B"and"C"res.Drychemical
extinguishing agents are dispensed
through a nozzle creating a dense cloud
thatblanketsthere.Itislessaffectedby
winds and drafts than clean agents but
leavesaresiduewhichinsomecasesmay
becorrosive.
Carbon Dioxide (CO2):
Carbondioxideisstoredasacompressed
gas. Carbon Dioxide as an extinguishing
agent displaces oxygen. It is discharged
fromitsstoragecontainerintheformofa
gasorsnowwhichisaffectedbywindsor
drafts.AsufcientconcentrationofCO2to
extinguish a re will not support life and
thereforepersonnelusingthisextinguishing
agent should take precautions to avoid
beingovercomefromlackofoxygen.
CO2 does not leave a residue making it
suitableforuseincomplicatedmachinery
and electronics and around food. CO2 is
particularlysuitableforClass"B"andClass
"C"reextinguishment.
2-11.3 USE OF PORTABLE FIRE
EXTINGUISHERS
General Considerations:
Itisrecommendedthatfamiliarizationwith
means for immediate extinguishment of a
reonboardisattained.
Know the location of every portable re
extinguisheronboard.
Anticipate the nearest one to be used for
possible res in the engine compartment,
machineryspaces,fueltankcompartment,
bilges,galley,adeckspilloffuel,etc.
Practice how to quickly remove each
extinguisherfromitsbracket.Perform"dry
run" trials with each extinguisher for the
hazard it protects, reviewing all motions
requiredtodischargetheextinguishertobe
readytoghtarequicklyanddecisively.
Dry Chemical
Foropenspillres,thedischargeshouldbe
applied in a sweeping motion across the
base of the ames of the re and work
upwards. Shut off or otherwise stop the
leak,ifpossible.