3 Fixed high-expansion foam fire-extinguishing
systems
3.1 Principal performance
3.1.1 The system shall be capable of manual release,
and shall be designed to produce foam at the required application
rate within 1 minute of release. Automatic release of the system shall
not be permitted unless appropriate operational measures or interlocks
are provided to prevent any local application systems required by regulation II-2/10.5.6 of the Convention
from interfering with the effectiveness of the system.
3.1.2 The foam concentrates shall be approved
by the Administration based on the guidelines developed by the Organizationfootnote. Different foam concentrate types shall not be mixed
in a high-expansion foam system.
3.1.3 The system shall be capable of fire extinction
and manufactured and tested to the satisfaction of the Administration
based on the guidelines developed by the Organizationfootnote.
3.1.4 The system and its components shall be suitably
designed to withstand ambient temperature changes, vibration, humidity,
shock, clogging and corrosion normally encountered on ships. Piping,
fittings and related components inside the protected spaces (except
gaskets) shall be designed to withstand 925°C.
3.1.5 System piping, foam concentrate storage
tanks, components and pipe fittings in contact with the foam concentrate
shall be compatible with the foam concentrate and be constructed of
corrosion resistant materials such as stainless steel, or equivalent.
Other system piping and foam generators shall be full galvanized steel
or equivalent. Distribution pipework shall have self-draining capability.
3.1.6 Means for testing the operation of the system
and assuring the required pressure and flow shall be provided by pressure
gauges at both inlets (water and foam concentrate supply) and at the
outlet of the foam proportioner. A test valve shall be installed on
the distribution piping downstream of the foam proportioner, along
with orifices which reflect the calculated pressure drop of the system.
All sections of piping shall be provided with connections for flushing,
draining and purging with air. All nozzles shall be able to be removed
for inspection in order to prove clear of debris.
3.1.7 Means shall be provided for the crew to
safely check the quantity of foam concentrate and take periodic control
samples for foam quality.
3.1.8 Operating instructions for the system shall
be displayed at each operating position.
3.1.9 Spare parts shall be provided based on the
manufacturer's instruction.
3.1.10 If an internal combustion engine is used
as a prime mover for the seawater pump for the system, the fuel oil
tank to the prime mover shall contain sufficient fuel to enable the
pump to run on full load for at least 3 h and sufficient reserves
of fuel shall be available outside the machinery space of category
A to enable the pump to be run on full load for an additional 15 h.
If the fuel tank serves other internal combustion engines simultaneously,
the total fuel tank capacity shall be adequate for all connected engines.
3.1.11 The arrangement of foam generators and
piping in the protected space shall not interfere with access to the
installed machinery for routine maintenance activities.
3.1.12 The system source of power supply, foam
concentrate supply and means of controlling the system shall be readily
accessible and simple to operate, and shall be arranged at positions
outside the protected space not likely to be cut off by a fire in
the protected space. All electrical components directly connected
to the foam generators shall have at least an IP 54 rating.
3.1.13 The piping system shall be sized in accordance
with a hydraulic calculation techniquefootnote to
ensure availability of flows and pressures required for correct performance
of the system.
3.1.14 The arrangement of the protected spaces
shall be such that they may be ventilated as the space is being filled
with foam. Procedures shall be provided to ensure that upper level
dampers, doors and other suitable openings are kept open in case of
a fire. For inside air foam systems, spaces below 500 m3 need
not comply with this requirement.
3.1.15 Onboard procedures shall be established
to require personnel re-entering the protected space after a system
discharge to wear breathing apparatus to protect them from oxygen
deficient air and products of combustion entrained in the foam blanket.
3.1.16 Installation plans and operating manuals
shall be supplied to the ship and be readily available on board. A
list or plan shall be displayed showing spaces covered and the location
of the zone in respect of each section. Instructions for testing and
maintenance shall be available on board.
3.1.17 All installation, operation and maintenance
instructions/plans for the system shall be in the working language
of the ship. If the working language of the ship is not English, French,
nor Spanish, a translation into one of these languages shall be included.
3.1.18 The foam generator room shall be ventilated
to protect against overpressure, and shall be heated to avoid the
possibility of freezing.
3.1.19 The quantity of foam concentrate available
shall be sufficient to produce a volume of foam equal to at least
five times the volume of the largest protected space enclosed by steel
bulkheads, at the nominal expansion ratio, or enough for 30 min of
full operation for the largest protected space, whichever is greater.
3.1.20 Machinery spaces, cargo pump-rooms, vehicle
spaces, ro-ro spaces and special category spaces shall be provided
with audible and visual alarms within the protected space warning
of the release of the system. The alarms shall operate for the length
of time needed to evacuate the space, but in no case less than 20
s.
3.2 Inside air foam systems
3.2.1
Systems for the protection of machinery
spaces and cargo pump-rooms
3.2.1.1 The system shall be supplied by both main
and emergency sources of power. The emergency power supply shall be
provided from outside the protected space.
3.2.1.2 Sufficient foam-generating capacity shall
be provided to ensure the minimum design filling rate for the system
is met and in addition shall be adequate to completely fill the largest
protected space within 10 min.
3.2.1.3 The arrangement of foam generators shall
in general be designed based on the approval test results. A minimum
of two generators shall be installed in every space containing combustion
engines, boilers, purifiers, and similar equipment. Small workshops
and similar spaces may be covered with only one foam generator.
3.2.1.4 Foam generators shall be uniformly distributed
under the uppermost ceiling in the protected spaces including the
engine casing. The number and location of foam generators shall be
adequate to ensure all high risk areas are protected in all parts
and at all levels of the spaces. Extra foam generators may be required
in obstructed locations. The foam generators shall be arranged with
at least 1 m free space in front of the foam outlets, unless tested
with less clearance. The generators shall be located behind main structures,
and above and away from engines and boilers in positions where damage
from an explosion is unlikely.
3.2.2
Systems for the protection of vehicle,
ro-ro, special category and cargo spaces
3.2.2.1 The system shall be supplied by the ship's
main power source. An emergency power supply is not required.
3.2.2.2 Sufficient foam-generating capacity shall
be provided to ensure the minimum design filling rate for the system
is met and in addition shall be adequate to completely fill the largest
protected space within 10 min. However, for systems protecting vehicle
and ro-ro spaces and special category spaces, with decks that are
reasonably gas-tight and that have a deck height of 3 m or less, the
filling rate shall be not less than two thirds of the design filling
rate and in addition sufficient to fill the largest protected space
within 10 min.
3.2.2.3 The system may be divided into sections,
however, the capacity and design of the system shall be based on the
protected space demanding the greatest volume of foam. Adjacent protected
spaces need not be served simultaneously if the boundaries between
the spaces are "A" class divisions.
3.2.2.4 The arrangement of foam generators shall
in general be designed based on the approval test results. The number
of generators may be different, but the minimum design filling rate
determined during approval testing shall be provided by the system.
A minimum of two generators shall be installed in every space. The
foam generators shall be arranged to uniformly distribute foam in
the protected spaces, and the layout shall take into consideration
obstructions that can be expected when cargo is loaded on board. As
a minimum, generators shall be located on every second deck, including
movable decks. The horizontal spacing of the generators shall ensure
rapid supply of foam to all parts of the protected space. This shall
be established on the basis of full scale tests.
3.2.2.5 The foam generators shall be arranged
with at least 1 m free space in front of the foam outlets, unless
tested with less clearance.
3.3 Outside air foam systems
3.3.1
Systems for the protection of machinery
spaces and cargo pump-rooms
3.3.1.1 The system shall be supplied by both main
and emergency sources of power. The emergency power supply shall be
provided from outside the protected machinery space.
3.3.1.2 Sufficient foam-generating capacity shall
be provided to ensure the minimum design filling rate for the system
is met and in addition shall be adequate to completely fill the largest
protected space within 10 min.
3.3.1.3 The arrangement of foam delivery ducts
shall in general be designed based on the approval test results. The
number of ducts may be different, but the minimum design filling rate
determined during approval testing shall be provided by the system.
A minimum of two ducts shall be installed in every space containing
combustion engines, boilers, purifiers, and similar equipment. Small
workshops and similar spaces may be covered with only one duct.
3.3.1.4 Foam delivery ducts shall be uniformly
distributed under the uppermost ceiling in the protected spaces including
the engine casing. The number and location of ducts shall be adequate
to ensure all high risk areas are protected in all parts and at all
levels of the spaces. Extra ducts may be required in obstructed locations.
The ducts shall be arranged with at least 1 m free space in front
of the foam delivery ducts, unless tested with less clearance. The
ducts shall be located behind main structures, and above and away
from engines and boilers in positions where damage from an explosion
is unlikely.
3.3.1.5 The arrangement of the foam delivery ducts
shall be such that a fire in the protected space will not affect the
foam-generating equipment. If the foam generators are located adjacent
to the protected space, foam delivery ducts shall be installed to
allow at least 450 mm of separation between the generators and the
protected space, and the separating divisions shall be class "A-60"
rated. Foam delivery ducts shall be constructed of steel having a
thickness of not less than 5 mm. In addition, stainless steel dampers
(single or multi-bladed) with a thickness of not less than 3 mm shall
be installed at the openings in the boundary bulkheads or decks between
the foam generators and the protected space. The dampers shall be
automatically operated (electrically, pneumatically or hydraulically)
by means of remote control of the foam generator related to them,
and arranged to remain closed until the foam generators begin operating.
3.3.1.6 The foam generators shall be located where
an adequate fresh air supply can be arranged.
3.3.2
Systems for the protection of vehicle
and ro-ro spaces and special category and cargo spaces
3.3.2.1 The system shall be supplied by the ship's
main power source. An emergency power supply is not required.
3.3.2.2 Sufficient foam-generating capacity shall
be provided to ensure the minimum design filling rate for the system
is met and in addition shall be adequate to completely fill the largest
protected space within 10 min. However, for systems protecting vehicle
and ro-ro spaces and special category spaces, with decks that are
reasonably gas-tight and that have a deck height of 3 m or less, the
filling rate shall be not less than two thirds of the design filling
rate and in addition sufficient to fill the largest protected space
within 10 min.
3.3.2.3 The system may be divided into sections,
however, the capacity and design of the system shall be based on the
protected space demanding the greatest volume of foam. Adjacent protected
spaces need not be served simultaneously if the boundaries between
the spaces are "A" class divisions.
3.3.2.4 The arrangement of foam delivery ducts
shall in general be designed based on the approval test results. The
number of ducts may be different, but the minimum design filling rate
determined during approval testing shall be provided by the system.
A minimum of two ducts shall be installed in every space. The foam
generators shall be arranged to uniformly distribute foam in the protected
spaces, and the layout shall take into consideration obstructions
that can be expected when cargo is loaded on board. As a minimum,
ducts shall be led to every second deck, including movable decks.
The horizontal spacing of the ducts shall ensure rapid supply of foam
to all parts of the protected space. This shall be established on
the basis of full scale tests.
3.3.2.5 The system shall be arranged with at least
1 m free space in front of the foam outlets, unless tested with less
clearance.
3.3.2.6 The arrangement of the foam delivery ducts
shall be such that a fire in the protected space will not affect the
foam-generating equipment. If the foam generators are located adjacent
to the protected space, foam delivery ducts shall be installed to
allow at least 450 mm of separation between the generators and the
protected space, and the separating divisions shall be class "A-60"
rated. Foam delivery ducts shall be constructed of steel having a
thickness of not less than 5 mm. In addition, stainless steel dampers
(single or multi-bladed) with a thickness of not less than 3 mm shall
be installed at the openings in the boundary bulkheads or decks between
the foam generators and the protected space. The dampers shall be
automatically operated (electrically, pneumatically or hydraulically)
by means of remote control of the foam generator related to them,
and arranged to remain closed until the foam generators begin operating.
3.3.2.7 The foam generators shall be located where
an adequate fresh air supply can be arranged.
3.4 Installation testing requirements
3.4.1 After installation, the pipes, valves, fittings
and assembled systems shall be tested to the satisfaction of the Administration,
including functional testing of the power and control systems, water
pumps, foam pumps, valves, remote and local release stations and alarms.
Flow at the required pressure shall be verified for the system using
orifices fitted to the test line. In addition, all distribution piping
shall be flushed with freshwater and blown through with air to ensure
that the piping is free of obstructions.
3.4.2 Functional tests of all foam proportioners
or other foam mixing devices shall be carried out to confirm that
the mixing ratio tolerance is within +30 to -0% of the nominal mixing
ratio defined by the system approval. For foam proportioners using
foam concentrates of Newtonian type with kinematic viscosity equal
to or less than 100 cSt at 0ºC and density equal to or less than
1,100 kg/m3, this test can be performed with water instead
of foam concentrate. Other arrangements shall be tested with the actual
foam concentrate.
3.5 Systems using outside air with generators installed
inside the protected space
Systems using outside air but with generators located inside
the protected space and supplied by fresh air ducts may be accepted
by the Administration provided that these systems have been shown
to have performance and reliability equivalent to systems defined
in 3.3. For acceptance, the Administration should consider the following
minimum design features:
-
.1 lower and upper acceptable air pressure and
flow rate in supply ducts;
-
.2 function and reliability of damper arrangements;
-
.3 arrangements and distribution of air delivery
ducts including foam outlets; and
-
.4 separation of air delivery ducts from the protected
space.
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