FIRE AND SAFETYFIRE AND SAFETY

PRINCIPLES OF FIRE PRINCIPLES OF FIRE FIGHTINGFIGHTING

PRINCIPLE OF FIRE FIGHTING

INTRODUCTION• A fire can be extinguished by destroying one or more of

the elements of the fire tetrahedron.• If the chain reaction is broken, resulting, reduction in

vapour and heat production will extinguish the fire. If the fuel, oxygen or heat is removed, the fire will die out

• Fire extinction, in principle, consists of the limitation or removal of one or more of four factors of the fire tetrahedron, and the methods of extinguishing classified as follow;– Starvation (fuel)– Smothering (oxygen)– Cooling ( heat)– Interrupt the chain reaction

Starvation

• Defines as the reduction or removal of the fuel supply.

• If the unburn fuel is taken away from the immediate vicinity of a fire, the fire does not extend to the unburn fuel.

• If it is in a liquid form or gas, turn off supply valve or shut down the supply of fuel, and therefore extinguish the fire

Smothering

• Reducing the oxygen level in the air to below 16%, which will then die when the surrounding oxygen is used up.

• The extinction of fire by shutting of doors, hatches and appropriates ventilation valves or shutters is a result of smothering.

• Other method is by application of extinguishing agents such as foam, carbon dioxide, dry chemical powder and dry powder for metal fires

Smothering: to separate the fuel from the oxygen. This can be considered as an attack on the edge of the fire tetrahedron where the fuel and oxygen sides meet

Cooling • The most commonly used method is to removed

the heat.• Water is a very effective heat absorber and

radiation feedback when properly applied.As a result, the chain reaction is indirectly attacked both on the fuel surface and the flame.

• The production of vapour and radiant heat is reduced

• Boundary cooling is one way of keeping all external sides of fire zones cooled with water spray to prevent spreading by conduction.

Cooling: to reduce the temperature of the fuel below its ignition temperature. This is direct attack on the heat side of the fire tetrahedron.

Interrupt chain reaction

• Fire can be extinguished by breaking the chain reaction.

• It normally direct attack the molecules structure or breaking down of compounds formed during the chain reaction process.

• The extinguishing agents commonly used to attack the chain reaction and inhabit combustion are dry powders and halons.

Chain breaking: to disrupts the chemical reaction process that sustains the fire

Additional • Oxygen dilution; to reduce the amount of

available oxygen below that needed to sustain combustion. This is an attack on the oxygen side of the tetrahedron

CO2

HEATOXYGENFUEL

CHAIN REACTION

Fire Fighting MediumFire Fighting Medium

FIRE EXTINGUISHING FIRE EXTINGUISHING AGENTSAGENTS

Factors affecting choice of Factors affecting choice of extinguishing agents:extinguishing agents:

• RIGHT CHOICE OF AGENT IS VERY RIGHT CHOICE OF AGENT IS VERY IMPORTANT SINCE IT WILL BE MORE IMPORTANT SINCE IT WILL BE MORE EFFICIENT THAN OTHERSEFFICIENT THAN OTHERS

• Efficiencies Efficiencies • Electrical conductorsElectrical conductors• Dangerous to personnelDangerous to personnel• Toxic levelToxic level• Effective / danger than fire itselfEffective / danger than fire itself• Type of fire involveType of fire involve

Selecting the wrong agents Selecting the wrong agents could:could:

• Transfer electrical hazardsTransfer electrical hazards• Toxic and dangerous to operatorToxic and dangerous to operator• Do more damage than the fire itselfDo more damage than the fire itself• Unable to extinguish the fireUnable to extinguish the fire• Create bigger fire spreadCreate bigger fire spread• Do increase rate of combustionDo increase rate of combustion• Promote an explosion / uncontrolled Promote an explosion / uncontrolled

situationsituation

FIRE EXTINGUISHING FIRE EXTINGUISHING AGENTSAGENTS

Water Water

• Abundantly available Abundantly available • lowering temperature below ignition pointlowering temperature below ignition point• Great cooling effects Great cooling effects • smothering action, starving the fire of smothering action, starving the fire of

oxygenoxygen• Turn into steam – smothering effect (oxygen Turn into steam – smothering effect (oxygen

starvation)starvation)• Best for class A – deep penetration to fire Best for class A – deep penetration to fire

seatseat• Excellent boundary coolingExcellent boundary cooling• Non toxic, non irritantNon toxic, non irritant

Water (cont/….)Water (cont/….)

• causing water damagecausing water damage• possibility of endangering the stability of possibility of endangering the stability of

the shipthe ship

• Unsuitable for electrical fire – good Unsuitable for electrical fire – good conductor conductor

• fire in cargoes - emit flammable gases fire in cargoes - emit flammable gases when wet conditionwhen wet condition

• Not extinguish low flash point firesNot extinguish low flash point fires• Cause explosion when in contact with Cause explosion when in contact with

certain chemicalscertain chemicals

SteamSteam

• Smother fire Replace air in protected Smother fire Replace air in protected compartment until insufficient oxygen levelcompartment until insufficient oxygen level

• Not suitable for “well established” fire – Not suitable for “well established” fire – steam will condensesteam will condense

• Condense steam acts as waterCondense steam acts as water• Must be continuously supply until fire Must be continuously supply until fire

completely extinction.completely extinction.• To be injected at lower level – lighter than To be injected at lower level – lighter than

airair• Not very effective agentNot very effective agent• No longer fitted in new buildingNo longer fitted in new building

Carbon dioxide (COCarbon dioxide (CO22))

• Smothering action – replace the air in Smothering action – replace the air in protected compartment - insufficient protected compartment - insufficient by diluting oxygenby diluting oxygen

• Non corrosiveNon corrosive

• Non electrical conductorsNon electrical conductors

• Leaves no residueLeaves no residue

• Consider easy to storeConsider easy to store

Carbon dioxide (COCarbon dioxide (CO22))

• Quality not deteriorate with agesQuality not deteriorate with ages

• Immediately available even dead shipImmediately available even dead ship

• Most substances – 12 ~ 16% O2 will Most substances – 12 ~ 16% O2 will sufficient to stop combustionsufficient to stop combustion

• For smouldering solid materials - 5% For smouldering solid materials - 5% O2 contents reqd for fire extinction. O2 contents reqd for fire extinction.

• Particularly suitable for enclosed Particularly suitable for enclosed spacesspaces

Carbon dioxide (COCarbon dioxide (CO22))

• used only in enclosed spaces used only in enclosed spaces

• limited quantity on boardlimited quantity on board

• not lowering the temperaturenot lowering the temperature

• Evacuation reqd before flooding the Evacuation reqd before flooding the spacespace

• Highly asphyxiating and slightly toxicHighly asphyxiating and slightly toxic

• 9% concentration cause unconscious 9% concentration cause unconscious

• Little cooling effectLittle cooling effect

Carbon dioxide (COCarbon dioxide (CO22))

• Danger of reignition if readmitted too Danger of reignition if readmitted too quickquick

• Generate static electricity during Generate static electricity during discharge – sufficient to produce sparkdischarge – sufficient to produce spark

• Unsuitable as inerting medium for Unsuitable as inerting medium for cargo tank and pump roomcargo tank and pump room

• Heavy storage container / Heavy storage container / comprehensive maintenancecomprehensive maintenance

• Disperses easily – undetectable Disperses easily – undetectable • colourlesscolourless

• Prepare fire watch systemPrepare fire watch system

• Increase crew awarenessIncrease crew awareness

• Extra precaution takenExtra precaution taken

• More simulation, discussion, drill, More simulation, discussion, drill, practices to carry outpractices to carry out

• More safety on hotworkMore safety on hotwork

When CO2 no longer When CO2 no longer available / being used up:available / being used up:

Halon Halon

• Inhibiting effect by stopping chain reactionInhibiting effect by stopping chain reaction

• used only in enclosed spacesused only in enclosed spaces

• limited quantity onboardlimited quantity onboard

• used in lower concentrations than carbon used in lower concentrations than carbon dioxidedioxide

• not directly dangerous for trapped personnelnot directly dangerous for trapped personnel

• Breaks down in a fire into toxic componentsBreaks down in a fire into toxic components

FOAMFOAM

• EFFECTIVE AGENT FOR FIRE INVOLVING EFFECTIVE AGENT FOR FIRE INVOLVING LIQUIDS.LIQUIDS.

• FORMED LAYER OF SMALL BUBBLES – FORMED LAYER OF SMALL BUBBLES – SEALED FUEL SURFACE & PREVENT SEALED FUEL SURFACE & PREVENT VAPOURISATION AND ACCESS OF AIR.VAPOURISATION AND ACCESS OF AIR.

• NORMALLY LIMITED QUANTITY ONBOARD NORMALLY LIMITED QUANTITY ONBOARD & SERVING AGES.& SERVING AGES.

• HAVE SOME COOLING EFFECT.HAVE SOME COOLING EFFECT.• SOME FOAMS CAUSING VARYING DEGREES SOME FOAMS CAUSING VARYING DEGREES

OF WATER DAMAGE.OF WATER DAMAGE.• 2 MAIN TYPES – CHEMICAL & MECHANICAL.2 MAIN TYPES – CHEMICAL & MECHANICAL.

CHEMICAL FOAMCHEMICAL FOAM

• PRODUCED BY INTERACTION OF ALUMINIUM PRODUCED BY INTERACTION OF ALUMINIUM SULPHATE & SODIUM BICARBONATE.SULPHATE & SODIUM BICARBONATE.

• FOAMING AGENT/ STABILISER (MAGNESIUM FOAMING AGENT/ STABILISER (MAGNESIUM STEARATE) NORMALLY ADDED.STEARATE) NORMALLY ADDED.

• WHEN MIXED TOGETHER, CO2 RELEASED AND WHEN MIXED TOGETHER, CO2 RELEASED AND PERFORMED 2 PURPOSES:PERFORMED 2 PURPOSES:– FILLING FOAM BUBBLES.FILLING FOAM BUBBLES.– PROJECTING THE FOAM FROM CONTAINER IN PROJECTING THE FOAM FROM CONTAINER IN

CONTINUOUS JET.CONTINUOUS JET.

• SO, FOAM IS A MASS OF CO2 BUBBLES.SO, FOAM IS A MASS OF CO2 BUBBLES.• DETERIORATE IN STORAGE.DETERIORATE IN STORAGE.

MECHANICAL / AIR FOAMMECHANICAL / AIR FOAM

• MIXING A FOAM CONCENTRATE WITH MIXING A FOAM CONCENTRATE WITH WATER IN CORRECT PROPORTION.WATER IN CORRECT PROPORTION.

• RESULTANT FORCED THRU SPECIAL RESULTANT FORCED THRU SPECIAL NOZZLE & BRANCH PIPE (APPLICATOR).NOZZLE & BRANCH PIPE (APPLICATOR).

• TURBULENCE OCCURRED RESULTANT AIR TURBULENCE OCCURRED RESULTANT AIR BEING INTRODUCED TO AGITATE THE BEING INTRODUCED TO AGITATE THE CONCENTRATE INTO SMALL AIR FILLED CONCENTRATE INTO SMALL AIR FILLED BUBBLES.BUBBLES.

• 4 MAIN TYPES OF AIR FOAM:4 MAIN TYPES OF AIR FOAM:

PROTEIN FOAMPROTEIN FOAM

• FROM ANIMAL WASTE PRODUCT FROM ANIMAL WASTE PRODUCT (BLOOD/HOOF & HORN) WITH (BLOOD/HOOF & HORN) WITH STABILISER ADDED.STABILISER ADDED.

• CREAMY COLOUR & UNPLEASANT CREAMY COLOUR & UNPLEASANT SMELL.SMELL.

• SOLUTION IS MIXTURE OF 3% OF SOLUTION IS MIXTURE OF 3% OF CONCENTRATE TO 97% OF WATER.CONCENTRATE TO 97% OF WATER.

• EXPANSION RATION 8 : 1.EXPANSION RATION 8 : 1.

FLUOROPROTEIN FOAMFLUOROPROTEIN FOAM

• NORMAL PROTEIN FOAM WITH FLUORINE NORMAL PROTEIN FOAM WITH FLUORINE COMPOUND ADDED.COMPOUND ADDED.

• SUPERIOR THAN NORMAL PROTEIN FOAM & MUCH SUPERIOR THAN NORMAL PROTEIN FOAM & MUCH MORE EXPENSIVE.MORE EXPENSIVE.

• PROBLEM WITH FOAM – WHEN PROJECTED ONTO PROBLEM WITH FOAM – WHEN PROJECTED ONTO BURNING FUEL, IT SUBMERGES BEFORE RISING BURNING FUEL, IT SUBMERGES BEFORE RISING TO FLOAT ON SURFACE, SOMETIMES BUBBLES TO FLOAT ON SURFACE, SOMETIMES BUBBLES ITSELF BURNS DUE TO CONTAMINATION WITH ITSELF BURNS DUE TO CONTAMINATION WITH FUEL.FUEL.

• THIS DOES NOT HAPPEN TO FLUOROPROTEIN THIS DOES NOT HAPPEN TO FLUOROPROTEIN FOAM - FUEL DOES NOT ADHERE TO IT. FOAM - FUEL DOES NOT ADHERE TO IT. (FLUORIN IS (FLUORIN IS A PART OF HALON COMPONENTS.A PART OF HALON COMPONENTS.

SYNTHETIC FOAMSYNTHETIC FOAM

• SIMILAR TECHNOLOGY TO HAIR SHAMPOO & SIMILAR TECHNOLOGY TO HAIR SHAMPOO & LIQUID DETERGENT.LIQUID DETERGENT.

• SOLUTION – 5% CONCENTRATE & 95 WATER.SOLUTION – 5% CONCENTRATE & 95 WATER.• WHITE COLOUR & LESS PERSISTENT THAN WHITE COLOUR & LESS PERSISTENT THAN

PROTEIN FOAM.PROTEIN FOAM.• SUPERIOR TO NORMAL FOAM, LESS EFFICIENT SUPERIOR TO NORMAL FOAM, LESS EFFICIENT

THAN FLUOROPROTEIN FOAM.THAN FLUOROPROTEIN FOAM.• VERY FLEXIBLE & CAN PRODUCED:VERY FLEXIBLE & CAN PRODUCED:

– LOW EXPANSION FOAM (UP TO 12:1).LOW EXPANSION FOAM (UP TO 12:1).– MEDIUM EXPANSION FOAM (UP TO 150:1).MEDIUM EXPANSION FOAM (UP TO 150:1).– HIGH EXPANSION FOAM (UP TO 1000:1).HIGH EXPANSION FOAM (UP TO 1000:1).

** ** MORE THAN 1000:1 IS UNSUITABLE – TOO THIN, AFFECT SMOTHERING & MORE THAN 1000:1 IS UNSUITABLE – TOO THIN, AFFECT SMOTHERING & COOLING.COOLING.

• LOW EXPANSIONLOW EXPANSION– APPLIED BY MONITOR / HAND HELD HOSES & APPLICATORAPPLIED BY MONITOR / HAND HELD HOSES & APPLICATOR– PROJECTED OVER CONSIDERABLE DISTANCE.PROJECTED OVER CONSIDERABLE DISTANCE.– FOAM WILL SCATTER IF TOO FAR.FOAM WILL SCATTER IF TOO FAR.

• MEDIUM EXPANSIONMEDIUM EXPANSION– HANDHELD ONLY, RANGE UP TO 15 METER.HANDHELD ONLY, RANGE UP TO 15 METER.– OPERATORS MUST WELL PROTECTED INCLUDING BA SET.OPERATORS MUST WELL PROTECTED INCLUDING BA SET.– SUITABLE FOR FIRE IN ENCLOSED SPACES.SUITABLE FOR FIRE IN ENCLOSED SPACES.

• HIGH EXPANSIONHIGH EXPANSION– CANNOT PROJECTED AT ALL.CANNOT PROJECTED AT ALL.– LED THRU DUCT / ALLOW TO FREE FALL.LED THRU DUCT / ALLOW TO FREE FALL.– USED TO ENTIRELY FILL COMPARTMENT UNDER FIREUSED TO ENTIRELY FILL COMPARTMENT UNDER FIRE– WHEN CONTACT WITH FIRE – FLASHED TO STEAM.WHEN CONTACT WITH FIRE – FLASHED TO STEAM.– GOOD COOLING EFFECT, EXCELLENT SHIELD AGAINST RADIANT GOOD COOLING EFFECT, EXCELLENT SHIELD AGAINST RADIANT

HEAT – PREVENTING SPREAD OF FIRE.HEAT – PREVENTING SPREAD OF FIRE.– EFFECTIVE AGAINST FIRE INVOLVING LOW FLASH POINT LIQUID EFFECTIVE AGAINST FIRE INVOLVING LOW FLASH POINT LIQUID

WHICH DIFFICULTY DISSOLVE IN WATER.WHICH DIFFICULTY DISSOLVE IN WATER.– PRODUCED BY SPRAYING THE SOLUTION ONTO FINE MESH NYLON PRODUCED BY SPRAYING THE SOLUTION ONTO FINE MESH NYLON

SCREEN.SCREEN.– AIR IS INTRODUCED BY LARGE FAN TO FORM HUGE MASS OF AIR IS INTRODUCED BY LARGE FAN TO FORM HUGE MASS OF

BUBBLES AT 1200 TO 5400 CUBIC FT / MIN DEPENDING ON SIZE.BUBBLES AT 1200 TO 5400 CUBIC FT / MIN DEPENDING ON SIZE.

Why not to exceed 1000?Why not to exceed 1000?

• Too thin for bubbles to formToo thin for bubbles to form

• Affecting:Affecting:– SmotheringSmothering– Cooling Cooling

ACQUEOUS FILM FORMING ACQUEOUS FILM FORMING FOAM (AFFF)FOAM (AFFF)• a.k.a. LIGHT WATERa.k.a. LIGHT WATER• FLUOROCHEMICAL BASED METTING AGENT & FLUOROCHEMICAL BASED METTING AGENT &

ABILITY TO FLOAT ON FLAMMABLE LIQUID WHICH ABILITY TO FLOAT ON FLAMMABLE LIQUID WHICH HAVE LOWER DENSITY THAN WATER.HAVE LOWER DENSITY THAN WATER.

• SOLUTION – 6% CONCENTRATE & 94% WATER.SOLUTION – 6% CONCENTRATE & 94% WATER.• DRIVEN THRU CONVENTIONAL AIR FOAM MAKING DRIVEN THRU CONVENTIONAL AIR FOAM MAKING

EQUIPMENT.EQUIPMENT.• EXPANSION RATION OF 8 TO 10:1.EXPANSION RATION OF 8 TO 10:1.• SPREAD RAPIDLY OVER SURFACE.SPREAD RAPIDLY OVER SURFACE.• ACTION – ENHANCES EXTINCTION & PREVENT ACTION – ENHANCES EXTINCTION & PREVENT

FLASH BACK EVEN FOAM BLANKET IS RUPTURED.FLASH BACK EVEN FOAM BLANKET IS RUPTURED.• MOST EFFICIENT BUT VERY EXPENSIVE.MOST EFFICIENT BUT VERY EXPENSIVE.

ALCOHOL FOAMALCOHOL FOAM

• NORMAL FOAM UNSUITABLE FOR FIRE NORMAL FOAM UNSUITABLE FOR FIRE INVOLVING WATER MISCIBLE LIQUID:INVOLVING WATER MISCIBLE LIQUID:– ALCOHOL ~ METHYL, ETHYL, ISOPROPYLALCOHOL ~ METHYL, ETHYL, ISOPROPYL– ESTER ~ ETHYL ACETATEESTER ~ ETHYL ACETATE– KETONES ~ ISOPROPYL ETHER, DIETHYL ETHERKETONES ~ ISOPROPYL ETHER, DIETHYL ETHER

• ABSORB WATER FROM FOAM – BUBBLES ABSORB WATER FROM FOAM – BUBBLES COLLAPSED.COLLAPSED.

• A.k.a. ALL PURPOSES FOAM – CAN USED A.k.a. ALL PURPOSES FOAM – CAN USED ON ORDINARY HYDROCARBON LIQUID ON ORDINARY HYDROCARBON LIQUID FIRES.FIRES.

• HOWEVER, QUANTITY REQD MAY HIGHER HOWEVER, QUANTITY REQD MAY HIGHER THAN PROTEIN FOAMS.THAN PROTEIN FOAMS.

FOAM FOR MARINE USEFOAM FOR MARINE USE

• MUST SUITABLE FOR USE WITH SEA MUST SUITABLE FOR USE WITH SEA WATER.WATER.

• MUST CAPABLE TO MAINTAIN AN MUST CAPABLE TO MAINTAIN AN EFFECTIVE SEAL OVER FUEL EFFECTIVE SEAL OVER FUEL SURFACE – REIGNITION DOES NOT SURFACE – REIGNITION DOES NOT OCCUR AT ANY POINT (BACK BURN).OCCUR AT ANY POINT (BACK BURN).

• FLUOROPROTEIN FOAM HAS A GOOD FLUOROPROTEIN FOAM HAS A GOOD BACK BURN CHARACTERISTIC.BACK BURN CHARACTERISTIC.

Foam Foam

• smothering action by blanketing the firesmothering action by blanketing the fire• limited quantity onboardlimited quantity onboard• choice of heavy, medium and light foamschoice of heavy, medium and light foams• each type required own nozzle of foam each type required own nozzle of foam

generatorgenerator• light foams used only in enclosed spaceslight foams used only in enclosed spaces• having some cooling effecthaving some cooling effect• some foams causing varying degrees of some foams causing varying degrees of

water damagewater damage

Chemical powderChemical powder

• inhibiting effect by stopping the inhibiting effect by stopping the chain reactionchain reaction

• limited quantity onboardlimited quantity onboard• causing damage to electrical and causing damage to electrical and

electronic equipmentelectronic equipment

Starvation Starvation

• cutting off fuel supply - situation:cutting off fuel supply - situation:– Engine room fire involving burst oil Engine room fire involving burst oil

pipespipes– Gas firesGas fires

• cutting off fuel supply – methods:cutting off fuel supply – methods:– closing supply valveclosing supply valve– stopping pumpsstopping pumps– dropping (emptying) high tanksdropping (emptying) high tanks

Smothering Smothering

• limiting the ingress of air:limiting the ingress of air:– stopping fansstopping fans– closing dampers and doorsclosing dampers and doors– Fire / smoke travelFire / smoke travel– Possibility for back draught Possibility for back draught

AUTO IGNITION TEMPAUTO IGNITION TEMP

MIN TEMP WHICH THE GENERATED MIN TEMP WHICH THE GENERATED VAPOUR WILL IGNITE SPONTANEOUSLY VAPOUR WILL IGNITE SPONTANEOUSLY WITHOUT ANY EXTERNAL SOURCE OF WITHOUT ANY EXTERNAL SOURCE OF IGNITION.IGNITION.AI TEMP FOR FO & LO ARE LOWER THAN AI TEMP FOR FO & LO ARE LOWER THAN THOSE OF LIGHTER FRACTION BECAUSE THOSE OF LIGHTER FRACTION BECAUSE CERTAIN PROPS IN LIQUID COMPOSITIONCERTAIN PROPS IN LIQUID COMPOSITION

METHANEMETHANE 700700ºCºCBENZENEBENZENE 742742ºCºCACETYLENEACETYLENE 422422ºCºCCYLINDER OILCYLINDER OIL 420420ºCºC

SUBSTANCE WITH LOW AI TEMP HAS SUBSTANCE WITH LOW AI TEMP HAS HIGHER FLASH POINTHIGHER FLASH POINT

CONT/..CONT/..

• THEREFORE WHEN CARRYING THEREFORE WHEN CARRYING CARGO:CARGO:– LOW AI & HIGH FP – TO ENSURE THE LOW AI & HIGH FP – TO ENSURE THE

SPACE ABOVE THE LIQUID LEVEL DOES SPACE ABOVE THE LIQUID LEVEL DOES NOT CONTAIN EXPLOSIVE MIXTURE.NOT CONTAIN EXPLOSIVE MIXTURE.

– HIGH AI & LOW FP – NOT TO HIGH AI & LOW FP – NOT TO OVERHEAT THE FUEL EXCESSIVELY OVERHEAT THE FUEL EXCESSIVELY WHICH RESULT IN SPONTANEOUS WHICH RESULT IN SPONTANEOUS IGNITION.IGNITION.