fire figthing

8/12/2019 fire figthing

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Marine Auxiliary machinery: Section: IV:Fire.

Notes for BE (Marine Engineering) Cadets.Notes Prepared By: Prof. K. Venkataraman. CEng; FIMarE; MIE.

Pre a!tions "gainst Fire:The only sure way to avoid the consequence of a disastrous fire at sea is not to have one.

Most ship fires in peacetime are caused y carelessness! i"norance! or stupidity. It is therefore the duty of allseafarers to see that they are not found "uilty on any of these counts.In accommodation the "reatest attention must e paid to the safe disposal of ci"arette ends and matches. #neshould always e certain that the match is actually extin"uished and the ci"arette end properly stu ed out

efore ein" put in a safe receptacle. The rotatin" top type of ashtray is safest as there is no chance of thecontents ein" scattered around the ca in should the ashtray slide off the ta le in rou"h weather. Matchesshould not e $ept loose and should e safety type! thou"h this name should not e ta$en too literally as they arestill lia le to self%i"nition under certain circumstances. All electrical appliances must e firmly secured andserved y permanent connections wherever possi le. If flexi le leads must e used they should e as short as

possi le and so arran"ed that chafin" or cuttin" of the wires in service is not possi le! whilst the correct si&e of plu" and soc$et with an effective earth connection should e used. 'ases have een found where two loose

wires to a porta le lamp were merely held into a soc$et y matchstic$s! and porta le lamps ein" so placed thatthey fell over in rou"h weather have caused fires. (eat from the electric li"ht ul itself can i"nite com usti lematerial and this is an all too common cause of fire. Ma$eshift paper shades! deeply charred! have een found inca ins and the occupants seem to have een lissfully unaware of the dan"er. #n no account shouldcom usti le material e allowed to come into contact with a na$ed li"ht ul proper shades should e provided.The correctly rated fuse should always e used in a circuit. )hen a fuse urns out repeatedly! one of heavierload is often fitted thou"h the fault! which may e in the wirin"! remains undetected. Similarly! the addition ofextra appliances to a circuit! which is not desi"ned to carry the additional load! will cause the wires to overheat!

producin" failure of the insulation! a short circuit and the resultant fire.The most usual cause of accommodation fires! however! has een the ha it of smo$in" in ed. It seems eyondcomprehension that people do not reali&e that *ust efore sleepin" the senses are dulled and it is impossi le to

e certain that the last ci"arette will e properly extin"uished. Althou"h people $now that this action has costthe lives of many others! they still elieve that they could not ma$e such a mista$e as to fall asleep whilstsmo$in".Many fires have ori"inated in ships+ "alleys! "enerally ecause of over heated pans of fat catchin" fire! utsometimes ecause of oil lea$a"e where oil fired coo$in" stoves were fitted.In car"o spaces! proper stowa"e and ventilation should prevent over heatin" and possi le spontaneouscom ustion and! providin" no ci"arette ends or un%extin"uished matches are dropped amon" the car"o! it will

e safe. Ille"al smo$in" in car"o and stora"e compartments and in for idden spaces such as the center castle ontan$ers has ta$en a heavy toll of oth ships and crews.In the machinery spaces! precautions should mainly ta$e the form of cleanliness! the prevention of oil lea$a"e!and the removal of all com usti le materials from vulnera le positions. ,ven a thic$ accumulation of paint!

often found in old ships! can help to spread a fire. To prevent oil%escapin" unseen the pipes carryin" hot oilunder pressure should e a ove the floor plates! li"htin" a ove and elow the floor plates should e ri"ht andcomprehensive! and clean save%alls should e placed under the urners and filters.

#il urners should e carefully assem led and any! which drip oil or um unevenly should e chan"ed. 'areshould e ta$en efore chan"in" urners and filters to ensure that there is no pressure on them when they areopened. All *oints and "lands in oil lines and at pumps should e $ept ti"ht and lea$a"e prevented! whilst all

oundary ars and the oil ti"ht coamin"s desi"ned to contain any overflow of oil should e intact and $eptclean. #il should not e allowed to accumulate on tan$ tops or in il"es and special care must e ta$en to

prevent any uncontrolla le overflow of oil from stora"e or settlin" tan$s. In this respect! some of thearran"ements provided in older ships for overflow pipes and for "au"in" the contents of the settlin" tan$s were


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very dan"erous. )ith the older float and wire type of "au"e! which fortunately is rarely found nowadays! the pulley carryin" the wire was often not carried far enou"h a ove the top of the tan$! so that should the tan$ eoverfilled the oil could overflow into the en"ine room or over the oilers. Fires are still caused y overflow

pipes not ein" led to a safe place and y loose or missin" flan"e covers on the top of the tan$. #il levelindicators should e of a type! which will not allow oil to escape in the event of dama"e to them and it is

prefera le that they should e of a type! which does not require piercin" of the lower part of the tan$.)ood! paints! spirits! tins of oil and ra"s or waste should not e $ept in oiler rooms or machinery spaces!secure stowa"e in the tunnel or steerin" "ear flat ein" suita le for such items! whilst dirty oil and oily ra"sshould not e allowed to accumulate.

All electric wirin" should e permanent! well maintained and $ept clean and dry! and not overloaded y the"radual addition of extra appliances.The question of smo$in" in the machinery spaces is a vexed one. It seems evident however that even in placeswhere the dan"er is "reater than in ship+s en"ine and oiler rooms! it is impossi le to ma$e certain that a nosmo$in" rule can e enforced! so that it is etter to admit that people will smo$e! and to provide suita lereceptacles for the disposal of the ci"arette stu s. 'ertain ships! e.". tan$ers and certain ul$ dan"erous "oodscarriers! will of course have to restrict the places where smo$in" may e allowed! ut it seems wise to ensurethat any person wishin" to smo$e should have the opportunity of doin" so in a safe place at reasona le intervals.

Ca!ses of #$ip%oard Fires:Some fires may e purely accidental and others may e caused y circumstances eyond control! ut many fires

have resulted from the acts or ne"li"ence of crew mem ers. 'arelessness and irresponsi le or ill%advised actionshave caused disastrous fires.

-o matter how a ship oard fire starts! it could result in the loss of the ship! and sometimes lives. It is thereforeextremely important that crewmem ers e constantly alert for situation that could cause fire a oard a ship.&$e ommon a!ses of s$ip%oard fire are:

. 'areless smo$in"./. Faulty electric circuits and equipment.0. Improper stora"e of spares and stores in en"ine room.1. 2alley operation.3. )eldin" and urnin" operations.4. 'arelessness of shore wor$ers while on oard.

'onspicuous 'N #M KIN * si"ns should e displayed in any part of the ship where smo$in" is for idden!whether permanently or temporarily. This should e o eyed in all circumstances.In places where smo$in" is authorised! ashtrays or other suita le containers should e provided and made useof.

'are should e ta$en to ensure that matches are actually extin"uished and ci"arette ends properly stu ed out.They should not e thrown over oard since there is a dan"er that they may e lown ac$.It is dan"erous to smo$e in ed since the smo$er may do&e off allowin" the lit ci"arette to drop onto the ed orcarpet.Smo$in" in the en"ine room is extremely dan"erous! and if it is to e permitted at all! a safe place should edesi"nated and proper containers partially filled with water provided.

5nauthorised persons should not meddle with electrical fittin"s. 6ersonal electrical appliance should econnected to the ship+s supply only with the approval of the ,lectrical #fficer or the responsi le ,n"ineer#fficer. -otices to this effect should e displayed on notice oards. Faulty electrical appliances! fittin"s orwirin"! which are part of the ship7s equipment! should e reported immediately to the (ead of department.All electrical appliances should e firmly secured and served y permanent connections whenever possi le.Flexi le leads should e as short as practica le and so arran"ed as to prevent their ein" chafed or cut inservice.Ma$eshift plu"s! soc$ets and fuses should not e used.'ircuits should not e overloaded since this causes the wires to overheat! destroyin" insulation and thusresultin" in a possi le short circuit! which could start a fire.All porta le electrical appliances! li"hts etc should e isolated from the main after use.


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-o personal porta le ca in heaters or stoves to e allowed. -otices to this effect should e displayed on notice oards.Spares should e properly stowed and $ept clean. Items such as cylinder liners should not e used as containersfor any purpose.Suita le containers should e provided for the stora"e of cotton waste! cleanin" ra"s or similar materials afteruse such containers should e emptied at frequent intervals and the contents safely disposed of.8irty waste! ra"s! sawdust and other ru ish! especially if contaminated with oil! are dan"erous if left lyin"a out. (eat may e "enerated spontaneously within such ru ish! which may e sufficient to i"nite flamma lemixtures or may ecome hot enou"h to set the ru ish itself on fire.

)ood! paints! spirits and tins of oil should not e $ept in machinery spaces or oiler rooms.962 is ein" increasin"ly used for ship oard coo$in" purposes. In addition to the ha&ard of fire and explosion!which may arise from such installations! there is also a ris$ of asphyxiation to personnel in the event of "aslea$a"e in enclosed spaces and should ventilation e deficient from car on monoxide poisonin" when theappliance is in use.The sittin" of "as containers and. the provision of adequate ventilation of the stora"e compartment and "alley istherefore of utmost importance.)arnin" notice in red should e displayed ad*acent to each appliance as follows:

+",NINBEF ,E -I &IN C ECK F , -E"K#

B/& NEVE, +I& " N"KE0 F-"ME-"CK F VEN&I-"&I N C"N P, VE F"&"-

Suita le mean for detectin" the lea$a"e of "as should prefera ly e provided in each! compartment containin" a"as%consumin" appliance. It should e securely fixed in the lower part of the compartment in the vicinity of the"as%consumin" appliance and should e actuated promptly and automatically y the presence of a "asconcentration in air not "reater than .3;.

)here oil%fired "alley stoves are used! the li"htin" up procedure should follow that of the oiler.2alley staff should ta$e particular care to avoid overheatin" or spillin" of fat or oil and to ensure that urners orheatin" plates are shut off when coo$in" is finished. ,xtractor flues and ran"es etc should always e $ept clean.

Means to smother fat or coo$in" oil fires! such as fire lan$et! should e readily availa le close to stoves.)eldin" and urnin" elsewhere than in the wor$shop should "enerally e the su *ect of a efore weldin"! flame%cuttin" or other hot wor$ is e"un! a chec$ should e made that there are no com usti lesolids! liquid or "ases at! elow or ad*acent to the area of the wor$! which mi"ht e i"nited y heat or spar$sfrom the wor$.)eldin" or other hot wor$ should never e underta$en on surfaces covered with "rease! oil or other flamma leor com usti le su stance.)hen weldin" is to e done in the vicinity of open hatches! suita le screens should e erected to prevent spar$sdroppin" down hatchways or hold ventilators. )here necessary! com usti le materials and dunna"e should emoved to a safe distance efore commencin" operations.

6ortholes and other openin"s throu"h which spar$s may fall should e closed where practica le.)here wor$ is ein" done close to or at ul$heads! dec$s or dec$ heads! the remote sides of the divisionsshould e chec$ed for materials and su stances! which may i"nite! and for ca les! 6ipelines or other serviceswhich may e affected y the heat.#il tan$s etc should e certified free of flamma le "ases efore any repair wor$ is e"un on them.Suita le fire extin"uishers should e $ept at hand ready for use durin" the operation. A person with a suita leextin"uisher should also e stationed to $eep watch on areas not visi le to the welder! which may e affected.In view of the ris$ of delayed fires resultin" from the use of weldin" or urnin" apparatus! appropriate frequentchee$s should e made for at least two hours after! cessation of wor$.8urin" temporary stoppa"e or after completion of the wor$! supply Valves on "as cylinders and "as mainshould e securely closed and lowpipes and hoses removed to loc$ers that open onto the open dec$ to prevent

uild up of dan"erous concentration of "as or fumes.


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#xy"en should never used to ventilate! cool or low dust of clothin".Shore wor$men! whether en"a"ed for car"o operation or repair wor$ may not e aware of the ha&ardsassociated with their actions! due pro a ly to the frequent chan"e of surroundin"s.1N #M KIN 2 si"ns shown e prominently displayed in prohi ited areas and responsi le crew%mem ersassi"ned for fire patrol duties and to enforce the no smo$in" rulin".A safe area should e desi"nated for their refreshments with direction indicators displayed alon" the route fromtheir wor$in" place. ,scape route direction indicators should also e displayed.

Potentia3 #o!r es of Fire in Ma $inery #pa es:Fa!3ty E3e tri Cir !its 4 E5!ipment:,lectrical equipment must e installed! maintained! tested and repaired in accordance with existin" re"ulations!and only y qualified personnel.They can ecome a source of i"nition and thus a fire ha&ard if they wear out! are miss used or are poorly wired!as electrical ener"y can e converted to heat.Standard industrial electrical equipment does not last very lon" at sea. The salt laden air cause corrosion!vi ration rea$s down the equipment and the steel hull can cause short%circuitin". As a result! the equipment orits wirin" may overheat or arc! causin" a fire if flamma le materials are near y.

Marine electrical equipment are specially desi"ned and constructed for ship oard use. 2iven reasona le

maintenance the will withstand the strenuous conditions at sea. Therefore when replacin" parts! only approvedtypes are to e used.Insulation on electrical wirin"! especially those of porta le equipment will a"e can ecome rittle and crac$.#nce the insulation is ro$en the are wire! is dan"erous! as a sin"le exposed wire can arc to any metal o *ectand produce enou"h heat to i"nite the insulation or other flamma le material.#ver%rated fuses or circuit rea$ers when used in a circuit will not rea$ the circuit! ut cause an increasedcurrent to flow and overheat the entire circuits. The insulation then may urn and i"nite flamma le materialnear y.,xposed li"hted electric ul s can i"nite com usti le materials y contact.Faulty electric motors are prime causes of fire. Spar$s and arcin" may result! if a windin" ecome short%circuited or "rounded! or if rushes do not operate smoothly.

The spar$ or are may e stron" enou"h to i"nite near y com usti le material. 9ac$ of lu rication may cause earin"s to overheat with the same result.)ater drippin" from ruptured or lea$in" sea water lines can cause severe short%circuitin" and arcin" in electricmotors! switch oards and other exposed electrical equipment.?uptured or lea$in" fuel and lu ricatin" oil lines a ove and near electrical equipment are even more dan"erous.F!e3 or -!%ri ating oi3 #pi33age on ot #!rfa e:2reat caution is required when! fillin" any settlin" or other oil tan$ to prevent! it! overflowin"! especially in theen"ine room where exhaust pipes or other hot surfaces is directly elow.6articular care should e ta$en when fillin" tan$s! which have their soundin" piper in the machinery spaces toensure that wei"hted coc$s are closed. In no case should a wei"hted coc$ on a fuel or lu ricatin" oil tan$soundin" pipe or on a fuel or lu ricatin" oil tan$ "au"e e securely in the open position.

If there is a lea$ in the oil pipin" the pressured oil will e sprayed out throu"h the rea$. Sprayin" tends tovaporise the oil! and the! vapours are easily i"nited. Thus line rea$s can e very ha&ardous if there are exhaust pipes! steam pipes! or any hot surfaces around.For this reason all steam pipes! exhaust pipes and fittin"s! which y their location and temperature present aha&ard! should e adequately la""ed or otherwise shielded. The insulation of heated surfaces should e propertymaintained! particularly in the vicinity of oil systems.>efore fuel is ein" transferred! the system should e chec$ed to ensure that strainers are in place and allflan"ed *oints are properly ti"htened. 8urin" transfer the system should e continuously chec$ed for lea$s." !m!3ation of i3y6,ags and +aste:


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?a"s and wastes soa$ed with oil or paint left in a warm and poorly ventilated area can lead to spontaneousi"nition. The oil on the ra" e"ins to oxidise! i.e. to react chemically with the oxy"en in the warm air around it.#xidation is a natural process that produces heat. Since the heat is not drawn away y ventilation! it uilds uparound the ra". After some time the ra"! "ets hot enou"h to urst into flames.

i3y Bi3ges:)aste oil should never e allowed to accumulate in il"es or on tan$ tops as this will allow the fire to spreadvery quic$ly! ma$in" the situation untena le.

Any accumulation should e disposed of in accordance with #il 6ollution ?e"ulations at the earliestopportunity. Tan$ tops and il"es should! wherever practica le! e painted a li"ht colour and $ept clean andwell illuminated in the vicinity of pressure oil pipes so that lea$s may e readily detected.Any source of oil lea$a"e should e located and repaired as soon as possi le.

Crank ase E7p3osion and /ptake Fire:

Cadets s$o!3d read t$e a%o8e se tion in detai3 in t$eir main Boi3er Notes and 0iese3 Engine Notes in t$eir#afety se tion to get t$e f!33 detai3s and !nderstand f!33y regarding t$ese fires:

'ran$case explosions have occurred in all types of enclosed cran$case en"ines includin" steam en"ines.A hot spot is an essential source of such explosion in cran$cases as it provides the necessary i"nitiontemperature! heat for oil vapori&ation and possi ly i"nition spar$. -ormal cran$case oil spray particles are"enerally lar"e to e easily explosive @avera"e / mB. (owever particle si&e of a out 4 m with the correct airratio can e explosive. A hot spot of a out+1 C' can vaporise lu ricatin" oil to this particle si&e! and in the

presence of an i"nition source and explosion can readily occur.A primary explosion occurs and the resultin" dama"e may allow air into a partial vacuum. A secondaryexplosion can now ta$e place! which is often more violent than the first.To prevent the condition in the cran$case reachin" the explosive ran"e cran$case oil mist detectors are fitted toena le constant monitorin" to e carried out and preventive measures ta$en. This device should e constantlyused and property maintained.

'ran$case explosion doors are fitted to release the pressure uild up! thus preventin" dama"e to the en"ineshould such an explosion occur. They are normally desi"ned to open at etween . 0% . D ar a oveatmosphere. ?elief area is ased on "ross cran$case volume and varies with different licensin" authorities utthis should not allow explosion pressures to exceed 0 ar.An accumulation of car on on the exhaust "as economi&er or silencer element surfaces! "enerally causedthrou"h poor com ustion! can e the source of a fire in the upta$e. In these fires car on on the tu es urn andmay cause serious dama"e to exhaust "as economi&er or silencer. To prevent such occurrences! everyopportunity should e ta$en of cleanin" the exhaust "as economi&er or silencer. 2ood com ustion should emaintained at all times.

Boi3er F!rna e B3o9 Ba k:

A notice should e displayed at each oiler settin" out operatin" instructions. Information provided y themanufacturers of the oil urnin" equipment should e! displayed in the oiler room.To avoid the dan"er of low ac$ when li"htin" oilers! the correct flashin" up procedure should always efollowed:

. There should e no loose oil on the furnace floor./. The oil should e at the correct temperature for the "rade of oil ein" used.0. The furnace should e lown throu"h with air to clear any oil vapour.1. The torch! specially provided for the purpose should always e used for li"htin" a urner! unless an

ad*acent urner in the same furnace is already lit. #ther means of i"nition! such as introducin" loose urnin" material into the furnace! should not e used. An explosion may result from attempts to re%li"hta urner from the hot ric$wor$ of the furnace.


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3. If all is in order! the operator should stand to one side and the li"hted torch inserted and fuel turned on.'are should e ta$en that there is not too much oil on the torch which could drip and possi ly cause afire.

4. If the oil does not li"ht immediately! the fuel supply should e turned off and the furnace ventilated yallowin" air to low throu"h for / or 0 minutes to clear oil vapour efore a second attempt to li"ht ismade. 8urin" this interval the urner should e removed and the atomi&er and tip inspected! to verifyhat they are in "ood order.

D. If! while the urner is ali"ht! there is a total flame failure in the furnace! the fuel supply should e turned

off.

" !m!3ation of i3 in t$e #tarting "ir #ystem:

&$is an a!se an e7p3osion 9it$ disastro!s onse5!en es. It is t$erefore re ommended t$at:. #il from any source should as for as practica le and! reasona le e excluded from air pipelines. In

particular air compressor dischar"e lines should e provided with means for effective interception anddrainin" of oil and water. If necessary! filters or separators should e fitted for this purpose and drains ofadequate si&e and num er should e fitted to air pipes! receivers and other fittin"s to avoid anyaccumulation of oil at low points in the system.

/. Startin" air valves should e properly maintained to avoid lea$a"e of hot com ustion "ases into the

startin" airline.0. 6eriodic inspections should! where practica le! include examination of air pipelines to ensure thatmeasures ta$en are effective.

1. #il force pumps should not e used to clear drain on startin" air pipelines.

t$ers:Many fires have occurred in ships under"oin" repair! and on investi"ation have een traced to weldin"operations.Fires arisin" from weldin" operations occur from various causes. In a num er of cases heat en"endered durin"the process was transmitted to flamma le material immediately ehind the point of weldin"! causin" thematerial to smoulder and fire to rea$ out at a later period.

#ther serious fires and explosions have resulted from weldin" operations carried out on or near oil tan$s and the practice is particularly dan"erous even if the tan$s are empty. A"ain! spar$s from an oxyacetylene urner havefallen on flamma le material! resultin" in fire and dama"e to car"o or stores.It is therefore necessary to ensure that efore weldin" operation commences there is no flamma le material

eneath or ehind the platin" in way of the repair! and that all necessary precautions are ta$en durin" weldin"operations. 6articular attention should e paid to open hatches and ventilators down which spar$s may dropuno served! and suita le screens should e erected.)here necessary car"o and dunna"e should e moved to a safe distance efore the operation is commenced!and in the case of oil tan$s these should e at least certified as "as%free.

A num er of serious fires have occurred in ship+s en"ine and oiler rooms due to oil overflowin" from fueltan$s onto the hot exhaust of main and auxiliary en"ines and oilers.

In order to pre8ent simi3ar a idents t$e fo33o9ing pre a!tions are re ommended:

. Steps should e ta$en to ensure that overflow arran"ements do not permit the overflowin" oil to comeinto contact with oilers! hot en"ine parts! or other heated surfaces where it mi"ht e i"nited. )here oil%ti"ht flats are fitted with drainpipes! these should prefera ly e open pipes! ut readily accessi le coc$swould not e o *ected to and may even e necessary where inter%floodin" of two separate waterti"htcompartments could occur throu"h the drains.


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/. #verflows from settlin" tan$s and daily service tan$s should e led ac$ to the stora"e tan$s or to anoverflow tan$. An alarm device should e provided to indicate when the tan$s are overflowin".

0. 'are should e ta$en to see that the soundin"s arran"ements or oil level indicatin" "ear on settlin" tan$sand daily service tan$s are such as will not permit the escape of oil should the tan$s e overfilled.

1. #il level indicators should e of a type! which will not allow oil to escape in the event of dama"e tothem. It is prefera le that they should e of a type! which does not require piercin" of the lower part of

the tan$. ?ound "au"ed "lasses should not normally e fitted to oil tan$s! ut suita ly protected "au"eshavin" flat "lasses of su stantial thic$ness and self%closin" may e allowed.

The experienced seafarer will $now that almost three times as many lives are lost in fires in the accommodationof ships as in their machinery spaces. Most of these deaths from fire occur on ships in port! often followin" ani"ht ashore! when the senses may e lurred! prior to actions such as the preparation of hot food or toast orcarelessness in the use of matches or ci"arettes when! say! smo$in" in ed. Such fires should not occur.Familiarity with the location of fire extin"uishin" equipment may limit their consequences ut one thin" iscertain%hundreds of lives would not have een lost in fire situations if everyone too$ the self%evident precautionof familiarisin" themselves with their livin" or wor$in" environment to the extent that they could find their way

to the exits in conditions of &ero visi ility.

Immediate3y after oining a s$ip ne9 offi ers or ratings s$o!3d %e a 5!ainted 9it$ t$e s$ip: (alons are to e phased out due to their o&one layerdepletion effectsB.


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Fire &etra$edron:

The three slopin" surfaces in the tetrahedron represent fuel! heat and oxy"en and the ase represents the chainreaction etween the short%lived chemical species followin" i"nition. As the temperature rises! the reaction rateincreases resultin" in a further rise in temperature. There is! however! an opposin" influence due to thedepletion of the fuel and its replacement y com ustion products and in the case! for example! of fuel urnin" inan open tray! the rate of evaporation of vapour from its surface will control the rate of reaction. In the case of aflamma le "as mixture! the speed of reaction is sufficiently hi"h to result in explosions.

If the chain can e ro$en! the fire will e extin"uished! i.e. the ase of the tetrahedron @which may econsidered as maintainin" the slopin" faces in placeB is destroyed. The halon extin"uishin" a"ents and certaindry chemicals effectively rea$ the chain reaction y attac$in" the structure of the active chemical species and

preventin" their reaction and so $illin" the flame sometimes in less than one hundredth of a second. (owever!halons have a minimal coolin" effect! and if their concentration is not maintained until sufficient coolin" hasta$en place or a coolin" medium has een applied! and the three slopin" sides of the tetrahedron are present! re%i"nition may occur.The fire ha&ard from liquid fuels is "enerally related to the flash point! i.e. the lowest temperature at whichsufficient vapour is released to form a mixture! which will i"nite on application of a flame. 9iquids! which willform a flamma le mixture at am ient temperatures! are not permitted as fuels for machinery spaces! ut other

properties of fuels are important from safety considerations.

6etroleum liquids will i"nite without the application of a na$ed flame if heated sufficiently! e.". when fuel orlu ricatin" oil lea$s onto hot surfaces. The temperature at which this i"nition occurs is much lower forlu ricatin" and fuel oils than for crude oil! petrol and $erosine. The i"nition temperature! for a "iven su stance@solid! liquid or "asB varies with the conditions of the test! e.". the ul$ of the su stance and its surface area. Forsolid materials! it is estimated y heatin" a sample in an oven or on a hot plate. &ypi a3 ignition temperat!resare :

. 'oal: 0 C'./. -ewspaper: E C'.0. 'otton! //EC'.

'onsequently! it is dan"erous to place oiled or paint splashed overalls! ra"s or waste on hot pipes. Such oiledmaterials! initially at room temperature! may cause fires throu"h heatin" due to the initial slow oxidation of theoil. This is an exothermic reaction within a "ood thermal insulatin" material! which will continue as lon" asoxy"en can diffuse inwards. The heat cannot readily escape and as the temperature increases so does thereaction rate until! in suita le conditions! the su stances urst into flames. The exothermic reaction is referred toas self or spontaneous heatin" and the su sequent fire as spontaneous com ustion. Therefore! oily or paintimpre"nated ra"s should never e stored near com usti les ut should e retained in airti"ht tins and disposedof ashore.#xidation is a chemical process in which a su stance com ines with oxy"en. 8urin" this process heat is "ivenoff. The rustin" of iron and rottin" of wood are examples of slow oxidation. Fire or com ustion is rapidoxidation the urnin" su stance com ines with oxy"en at a very hi"h rate! "ivin" of ener"y in the form of heat

and li"ht @flamesB.

fire figthing

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