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8/13/2019 Safety FFA
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Created by Ankur Sharma, Gurudayal Srivastava, Vikram Singh, Sanket Tamhane
1. Foam fire fighting system, requirements.
All foam systems consist of a water supply, foam liquid storage, a proportioning device and a distribution system The
water supply pump!s" provide!s" a certain capacity of seawater to the deck foam system, and is#are supplied by the
ship$s fire pumps
The foam liquid is stored in a tank The tank must be complete with vent, contents gauge, and access manhole The
foam is delivered via a high pressure foam liquid pump to the automatic foam liquid proportionator, which willaccurately proportionate foam liquid at %& to '& to the seawater flow, irrespective of flow rate or pressure
(or satisfactory operation of the proportionator, foam liquid must be supplied with a minimum pressure of at least )*
meters head higher than the inlet water pressure under all load conditions The electrically driven foam liquid pump is
provided for this purpose
(oam solution is supplied to the deck monitors and hand lines by the deck main fitted with isolating valves +ach
monitor is isolated from the main supply pipe by means of butterfly valves, which are normally close
ow e-pansion foam is used to create a blanket above the tank top in the machinery space+-pansion ratio should not
e-ceed )./)0t should cover entire floor area to a depth of )1* mm within 1 minutes
2igh +-pansion foam is used to fill up the entire space +-pansion ratio should not e-ceed )***/)3ate of discharge issuch that depth of ) meter is covered in every ) minute (oam generator is used for this purpose 4uantity of foam
making compound onboard should be sufficient enough to produce foam volume 1 times the volume of the largest space
served This system is fitted for machinery spaces, pump room and cargo spaces
(oam system is also used to cover tank decks of tankers (oam should be supplied at the rate of ).1* litres#minute or '
litres#minute#sqmetre area served by the largest monitor or *' litres#min#sqmeter area of the entire cargo tank deck
whichever is higher The supply should last for %* minutes (oam applicator should have capacity of 5** liters#min and
throw of )1 m in still air condition
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0f vapour pressure of the cargo at %678c e-ceeds )*)% bar, regular foam is not effective Alcohol resistant foam should
be used in such cases
9echanical foam system is usually operated by pumps A venture proportionator unit is fitted in the line:ater pressure
is 6 bar;art of the water enters the tank containing the foam liquid, and pushes the liquid through the syphon tude to the
other side of the venturiThe mi-ture of foam liquid and water in right proportion is led to the foam making noattery room The room should be well ventilated prior to entry There should
be an e-haust fan that starts as soon as the door is opened and should provide ' air changes per hour The temperature of
the room should be maintained between *8c to '*8c
Procedure to follow after co2 is released in the compartment:
Allow sufficient time for the fire to get e-tinguished Temperature of the boundary divisions will give indication Team
of .?% persons with breathing apparatus and portable fire e-tinguishers should enter space with caution +nsure no
traces of fire and smoke =pen skylights, ventilators, etc to admit clean air After sufficient ventilation start the
machineries one by one @o not start the machinery affected by fire or fire fighting medium
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#. raw de"$ seal on your ship and also draw any alarms or trips on it.
Wet Type Deck Water Seal
The picture below shows the construction of a wet type deck water seal and its functioning >asically it consists of a
chamber semi?filled with water and two pipes for inlet and outlet of flue gases while another two small pipes denote
inlet and outlet for sealing water There is a demister pad to remove water droplets from gas The operation of this
device is pretty simple and the two diagrams shows conditions where the inert gas is flowing from the plant to the
distribution area and the right hand side showing a condition where back pressure tends to push cargo gases into the 0G
system and is prevented by the water seal
Semi Dry Type Deck Water Seal
The construction of this type of seal as well as the functioning under both conditions is shown in the diagram below
The main difference with the previous type of seal is that it uses venture action to draw water when there are chances of
backflow of the gases thus reducing if not completely eliminating water carry over to the cargo tanks
Dry Type Deck Water Seal
This seal totally eliminates any water carry over and uses automated valve control to deliver water to the seal in case
there is any back flow but the only disadvantage is that if automation system fails then there is a danger of blow back of
cargo gases
The only alarm is @eck water seal low level alarm
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%. &xplain '(2 system with diagram. Why isolating )al)es are pro)ided on the manifold. &xplain all the safeties.
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*. +ypes of dete"tors onboard.
The use of fire detectors is increasing, particularly with the tendency to reduced manning and unmanned machinery
spaces A fire, if detected quickly, can be fought and brought under control with a minimum of damage The main
function of a fire detector is therefore to detect a fire as quickly as possible it must also be reliable and require a
minimum of attention An important requirement is that it is not set off by any of the normal occurrences in the
protected space, that is it must be appropriately sensitive to its surroundings Three phenomena associated with fire are
used to provide alarms/ these are smoke, flames and heat, The smoke detector makes use of two ionisation chambers
one open to the atmosphere and one closed !(igure )%)" The fine particles or aerosols given off by a fire alter the
resistance in the open ionisation chamber, resulting in the operation of a cold cathode gas?filled valveThe alarm sounds
on the operation of the valve to give warning of a fire Smoke detectors are used in machinery spaces, accommodation
areas and cargo holds (lames, as opposed to smoke, are often the main result of gas and liquid fires and flame detectorsare used to protect against such ha
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. -s there a safety )al)e on fire main?
A relief valve is necessary in the fire main if the pumps are capable of raising the pipeline pressure to an e-tent that it is
greater than the designed pressure for the pipeline Also certain situations like taking water from the international shore
connection from shore or other vessel and there rate of pump discharge to be taken into consideration it is always wise
to implement a safety valve in the fire main
. -solation )al)es on fire main, -ts use if fire on main de"$ and engine room?
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0n tankers, isolation valves shall be fitted in the fire main at the poop front in a protected position and on the tank deck
at intervals of not more than 5* m to preserve the integrity of the fire main system in case of fire or e-plosion
1/. What basi" "he"$ do you thin$ you should do while entering the "o2 room?
Covered above
11. (n an oil tan$er fixed fire fighting system onboard.
3efer Answer )
12. (n de"$ what type of system you use? Why only low expansion foam? Why not high expansion foam? 0nd
where high expansion foam is used?
=n deck we use low e-pansion foam system if we use high e-pansion foam on deck there are chances of fire spreading
and agitating due to the convection currents and high wind speed possibilities :e use high e-pansion foam in enclosed
spaces like engine room,cargo spaces,pump room,etc!not sure of the answer"
13. Hyper ist system.
:ater mist !fog" sprinklers are being used as an alternative to, the now banned, 2alon fire suppression systems The
mist system delivers very small water particles, which are able to remain suspended in the air The water particles are
evaporated by the heat of the fire and the e-panding vapour displaces o-ygen The combined cooling and o-ygen
starvation effects quickly e-tinguishes a fire 0n this system less water is used than with sprinkler systems and the mist
has proved effective against liquid fuel fires, making it suitable for use in machinery spaces 3esearch is continuing, in
particular as to the effectiveness of mist in a large machinery space :ater mist is accepted as a fire e-tinguishing agent,
with respect to S=0AS fire protection requirements
1!. From where do you maintain water supply to hyper mist system?
:ater supply is maintained from the fresh water port side tank 0n my ship minimum water level should be kept )*1 m%
for the safe operation of the system
These are very high pressure water mist systems =n operation it creates a water fog which effectively puts out the fire
while also providing a quenching or cooling effect 0t is also automatically activated when two different types of fire
detectors are triggered in the same fire
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1*. '(2 system wee$ly "he"$s.
) :eekly inspection for alarm system
. All the pulley, wire, rope and toggle must be free from dirt, scales and well lubricated
% >ottles should not be e-posed to temperature of '*BC
1. raw "o2 portable extinguisher. -ts safeties.
How it wor$s.
0ns4 A very strong container is used to store liquid
carbon dio-ide under pressure !(igure 13.%5. 0central tube provides the outlet passage for the
carbon dio-ide which is released either by a plunger
bursting a disc or a valve operated by a trigger The
liquid changes to a gas as it leaves the e-tinguisher
and passes through a swivel pipe or hose to a
discharge hornCarbon dio-ide e-tinguishers are mainly used on
Class > and C fires and will be found in the
machinery space, particularly near electricalequipment The carbon dio-ide e-tinguisher is not
permitted in the accommodation since, in a confined
space, it could be lethal
1. raw me"hani"al foam system with all its
"ontents.
3efer Answer )
2/. 6hip "oming out of dry do"$ after ma7or
"hanges in fire system. 8ou 7oin the ship and how
will you "ome to $now?
21. How will you "al"ulate the no. of "o2 bottles for engine room?
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C=quantity shall be sufficient to give a minimum volume of free gas (or machinery space, equal to 5*& of gross
volume, e-cluding casing +qual to %1& of gross volume, including casing
Volume of free gas in a bottle shall be *1' m# kg (4 k! C"# $ottle%
Therefore,*1'-51D.1. m
Thus 5*& of gross volume of machinery space e-cluding casing #.1. will give you the number of co. bottles required
for the space to be protected
22. 6afeties in fixed "o2 system and in "o2 room. raw "o2 "abinet alarm "ir"uit diagram.
23. Fixed Fire fighting in de"$ and engine room.
Covered above
2!. e"$ fire fighting arrangement on 9:;.
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@C; and high pressure water fog system
2%. -f there is fire in the engine room and it is de"ided to release "o2 , what a"tions to be ta$en before release?
C=flooding to machinery space must be done by master$s order
C=must be released by competent engineer, C+ or .#+
:hen ca$inet door is opened alarm will sound and all +3 fans will be stopped
>efore releasing, all +3 crew to be counted
All openings must be shut Eventilator flaps, fire damperF
'll f$el p$mps and ($ick closing #al#es of f$el tanks and f$el transfer line m$st be sh$t from remote contro
position.
2*. 6afeties prior to entry of "o2 room.
Covered above !ventilation should be on, Temp of the room should be maintained less than '*8c"
2. Fixed "o2 system.
Covered above
2. Whi"h extinguishing medium for de"$? raw foam system entire line for de"$ and engine room. Foam
expansion ratios.
Covered above
3/. What will happen if fire main de"$ line is "ra"$ed and you want water in fire hydrants on de"$?
Cracked fire main line is a maor non?conformity, psc detention 3epair, 3enew the pipeline as soon as possible Hotify
flag state,company supdtThat such non? conformity was found during inspections Class is to be informed about it0f
temporary measures are taken, a condition of class is issued for % months to 1 years depending upon whether the work
can be carried out during operation of ship or emergency dry dock or in dry dock :hen permanent repairs are carried
out the class is to be informed again Class surveyor will inspect the repairs, testing to be done, satisfactory completion,
condition of class will be removed Temporary repairs can be done for fire fighting purpose but notify all parties the
intention for it
31. How will you as"ertain that #< of "o2 has been dis"harged within 2 minutes?
32. Haards on +an$ers.
Cargo carried in tankers is flammable and gives vapours which can cause e-plosion Special care is required in
designing and operating tankers =fficers are reqd to have tanker safety certificates ;ump room atmospheres can be
highly ha
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Covered above
3%. What is the pressure setting of relief )al)e in "o2 fixed fire fighting system? What safeties are pro)ided in
"ase if "o2 room itself is on fire?
+ach bottle has a combined&urstin! Disc, which will rupture spontaneously at a pressure of )66 bar at '%BC0f in casethere is fire in the co. room itselfIthe bursting disc ruptures and the discharge of co. is led into the co. battery room
itself
3*. 0fter "o2 release from where will you enter in the engine room? How many entran"es are there in the engine
room?
After co. flooding for fire fighting in the engine room allow sufficient time for the compartment to cool down The
temp of the boundary divisions can be used as an indicator A team of .?% persons with scaba enters the compartment
and looks out for fire and e-tinguish if present with the help of portable e-tinguishers =nce it has been confirmed that
there are no traces of fire and that the fire has been completely e-tinguish and fire cannot reignite all the openings like
ventilators, skylights are opened one by one The compartment is thoroughly ventilated Always ensure proper
ventilation while entering the machinery space for damage survey# inspection Since co. is heavier than air there is
danger of gas pockets under plates, in corner and in any area in which air circulation may be difficult =nce all safeties
are ensured entry can be made from the topmost deck +ntrances to the engine room? (unnel deck, +conomiser
platform, Steering flat aft entrance, emergency escape route, upper deck engine room entrance
This should be done from the tunnel, if there is one, or the lowest point remote from the seat of the fire
3. Fire on main engine "ylinder head. How to extinguish and type of "ylinder?
a% Sufficient no of 51 litre capacityfoam type e-tinguishers, to enable foam to be directed onto fuel and =
pressure system, gearing and other fire ha
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!1. Why is "o2 stored at #3 bar?
!2. (n what prin"iple does ': extinguishes fire?
@ry powder acts to smother a fire in a similar way to a blanket =wing to the great shielding properties of the powder
cloud the operator can approach quite close to the fire The sodium bicarbonate powder will, due to the heat from the
fire, produce C"2 which should further assist in smothering the fire
!3. 6$et"h and explain portable ': fire extinguisher.
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!!. 6tandard fire test?
Standard fire test means a test in which specimens are e-posed in a test furnace to temperatures corresponding
appro-imately to the standard time?temperature curve
!#. 6ustained flaming.
Sustained flaming means a presence of flames on or over any part of a specimen lasting 1 seconds or longer
!%. =on > "ombustibility test.
Acceptance criteria of non combustibility/
aterials to be "lassified as non"ombustible to be shall satisfy the following "riteria4
The average furnace thermocouple temperature rise does not e-ceed %*8C
The average specimen surface thermocouple temperature rise does not e-ceed %*8C
The average duration of sustained flaming does not e-ceed )* seconds and
The average mass loss does not e-ceed 1*&
!*. -n hyper mist system how does the 11 bar @5 pump generates a fine mist? 6ur)eyor as$ed the spe"iality of the
nole?@-n"omplete5
@iffuser action in Ho
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