FIRE FIGHTING SYSTEMS
Fixed fire fighting systems
• A variety of different fixed fire fighting
installations exist, some of which are specially
designed for certain types of ship. A selection of
the more general installations will now be
obtained as follow;
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Ship’s fire main system
Carbon Dioxide System
Water Spray System
Foam Systems
Inert Gas System
Ship’s fire main system
• A sea water supply system to fire hydrants is fitted
to every ship using several pumps in the engine
room with their number and capacity being
dictated by legislation.
• an emergency fire pump will also be located
remote from the machinery space and with
independent means of power
• A system outlet fitted with isolating valves located
around the ship, and hoses with appropriates snapin connectors are strategically located together
with jet or spray types nozzles to covered the
whole ship area
• An international shore connection is always
carried onboard with standard flange size which is
fitted with a coupling suitable for the ship’s hoses.
Emergency Fire Pump
• In order to deal with the outbreak of fires, it is
required by regulation that an independent
pumping unit to be placed on board at such a
position that it is away from the main possible seat
of fire or damaged by collision
• The pump is of a centrifugal type completed with
priming unit run by a small diesel engine which is
can be started by hand cranking
• Unit shall be tested regularly and kept in a state of
readiness at all times
Pumps requirements
• Independent power unit driven by a self cooled
compression ignition engine or an electric motor
driven by electric power from emergency generator
• Independent sea suction with total head suction of
the pump shall not exceed 4.5 meter under all
conditions of list and trim
• Capacity not less than 25cubic meter per hour
• Capability to supply two ½ inch bore jets of water
having a horizontal throw of 40 feet
• All associate components located outside engine
room or machinery area
• Easy to start and fuel service tank capable to run on
full load at least 3 hours operation (15 hours for
outside machinery space)
CO2 Flooding System
• CO2 Flooding System for cargo holds
• CO2 Flooding System for machinery space
• Bulk Carbon Dioxide System
CO2 Flooding System for cargo holds
Diverting valve
Detecting
cabinet
generally
located in
bridge
CO2 battery (possibly
situated in a deck house)
• Gases from the compartment is drawn
continuously by suction fans to diverting valve
into the wheelhouse through an electrical smoke
detector via nylon propellers which should be
continuously whirling to indicated sampling tube
is not blocked
• When a fire breaks out in a compartment, smoke
issues from diverting valve into the wheelhouse to
sound an electrical smoke detector alarms
• Identification of defected compartment can be
seen from diffused light from a chimney
• Operator would first operate the appropriate
change over valve which are generally situated
inside the lower portion of the cabinet before
releasing requisite number of CO2 cylinders for
the compartment.
CO2 Flooding System for
Machinery space
• To be effective in smothering effect, at least 30% of
the gross volume of the compartment to be covered
and the flooding system must release to obtained
40% of the gross volume of the compartment and
held until the fire is out
• This system are arranged to release at least 85% of
the CO2 capacity within two minutes.
• Incase of fire, first evacuated all personnel and sealed
off the compartment (engine room) from any ingress
of air either manually or automatically or equivalent.
• While opening the steel control box situated at the
fire control station will operate audible and visual
alarms
• The CO2 direction valve handle would then be pulled
and this would be followed by gas release to the
compartment
Bulk
Carbon
Dioxide
System
• The system was designed to replace the flooding
systems for machinery and hold spaces which use a
considerable number of bottles consists essentially of
one or two pressure tanks and appropriate network of
pipes for distributing the gas around the machinery
spaces.
• Cylindrical container well insulated which hold CO2 at
working temperature and pressure about - 20°c and 21
bar.
• Duplicated refrigeration units automatically controlled
by the pressure of the CO2 are used, one in used other
in standby in order to maintained tanks temperature
• Since it is essential that pressure in the container
maintained for fire extinguishing within set range a
heater cuts in is required to increase the pressure of
CO2
• Two set of relief valve are fitted which are
operated 24.5 bar (Lp)and 27 bar (Hp) venting in
the event of fire in the compartment where the
container is situated.
• Alarms are provided for;
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Loss of 5% of contents (low level)
Increases up to 98% of free volume (high level)
Leakage past main discharge valve
Opening of section valve
Water Spray System
• Automatic Sprinkler System
• High Pressure Water Spray System
Automatic Sprinkler System
• The sprinkler system is an automatic fire detecting,
alarm and extinguishing system that is constantly 'on
guard' to deal quickly and effectively with any out
break of fire that may occur in accommodation or any
other spaces.
• The system is composed of a pressurised water tank
with water pipes leading to various compartments
which is occupied with not more than 150 heads per
section of sprinkler heads fitted and come into
operation when there is an outbreak of fire
• Each sprinkler head is made up of a steel cage fitted
with a water deflector, a quartzoid bulb, which
contains a highly expansible liquid, is retained by the
cage. The upper end of the bulb presses against a
valve assembly which incorporates a soft metal seal.
• The quartzoid bulbs are manufactured with a small
gas space is left inside the bulb so that if the bulb is
subject to heat, the liquid expands and the gas space
diminishes. This will generate pressure inside the
bulb and the bulb will shatter once a predetermined
temperature (and hence pressure) is reached.
• Quartzoid bulbs are manufactured in different
colours, the colour indicates the temperature rating
for the bulb:
– 68oC – Red
– 80oC – Yellow
– 93oC – Green
• Once the bulb is shattered the valve assembly falls
permitting water to be discharged from the head,
which strikes the deflector plate and sprays over a
considerable area.
High
Pressure
Water Spray
System
• This can be a completely separate system or may
interconnected with the sprinkler system used for fire
extinguishing in accommodation spaces
• The system incorporates an air vessel, fresh water pump
and salt water pump all connected to each sections
piping which having its own shut-off valve and sprayer
heads (no quartzoid bulbs or valves but are open as
sprinkler)
• The system is full of fresh water under pressure from
the compressed air in the air vessel. When a section
valve is opened, water will be discharged immediately
from the open sprayer heads in that section.
• Pressure drop in the system automatically starts the salt
water pump which will continue to deliver water to the
sprayers until the section valve is closed.
• After use the system should be flushed out and
recharged with clean fresh water.
• The air vessel is incorporated into the system to
prevent the pump cutting in if there is a slight
leakage of water from the system.
• To test:
– This should be carried out at weekly intervals:
• Open A, close B, open C;
– The pump should automatically start and
discharge from A. This avoids having to refill
the system with fresh water.
Foam systems
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Mechanical foam installation
Pre-mixed foam installation
Foam compound injection system
High expansion foam system
Mechanical Foam
Installation
• Capability supplying foam to tank top areas with sufficient
capacity to give a depth of foam of at least 152mm over
the whole tank top.
• Water at a pressure of at least 6 bar supplied from the
ships main, passes through the water control valve into the
venturi fitting
• Two small bore pipes ‘A’ and ‘B’ are connected to the
venturi fitting as a high pressure pipe led through a water
meter to the top of the foam compound tank and a low
pressure pipe which permits a controlled quantity of foam
compound to be entrained into the venturi fitting
• The protein foam compound and water pass through along
the main delivery pipe to the foam makers situated in the
boiler or engine room, as the mixture passes through the
foam maker air is entrained which then produces a stable
foam which is delivered to the foam spreaders.
Pre-mixed foam installation
• This is self contained by means of does not require
motive power from the ship pump however using
operated by CO2
• Co2 delivered at a pressure 42 bar to the metering
valve and as it pass through the orifice plate it falls
in pressure to 8 bar or less
• The solution in the storage tank is driven out via
the delivery pipe to the foam makers situated in
the boiler or engine room spaces and pump room
for tankers or even to a hydrant system, wherein,
air is enters the system and foam is produced for
distribution to the foam spreaders
Foam compound injection system
• This system often found on tankers for deck and
machinery spaces
• Foam compound is drawn from the sealed tank by
the compound pump and air enters the tank
through the atmospheric valve which is linked
with compound valve and simultaneously
delivered to automatically regulated injector unit
• The injector unit controls the amount of water to
compound ratio for a wide range of demand by the
foam spreaders
• A fire pump delivers the foam making solution at
sufficient pressure to the deck monitors (multidirectional type foam guns) so that foam can reach
any part of the deck or to the machinery spaces
spreaders
High Expansion Foam System
• The generator are large scale bubble blowers which are
connected by large section trunking to the compartments
• A 11/2 m long, 1 m2 generator could produce about 150
m3/min of foam which would completely fill the average
engine room in about 15 minutes.
• 1 liter of synthetic detergent foam concentrate combines
with 30 to 60 liters of water to give 30K to 60K liters of
foam
• Advantages
– Economic or can be rapidly produced
– Could be used with existing ventilation system
– Personnel can walk through with little ill effect
• Disadvantages
– Taking up to 48 hours to die down in enclosed space
– Large trunking required
– Trunked to bottom of compartment to prevent blown away