3 Principal requirements for the system
3.1 The system should be automatic in operation, with no human
action necessary to set it in operation.
3.2 The system should be capable of both detecting the fire and
acting to control or suppress the fire with a water-based extinguishing medium.
sprinkler system should be capable of continuously supplying the water-based
extinguishing medium for a minimum of 30 min. A pressure tank or other means
should be provided to meet the functional requirement stipulated in the FSS
Code, chapter 8, paragraph 22.214.171.124. The design of the system should ensure
that full system pressure is available at the most remote nozzle in each
section within 60 s of system activation.
3.4 The system should be of the wet pipe type but small exposed
sections may be of the dry pipe, preaction, deluge, antifreeze or other type to
the satisfaction of the Administration where this is necessary.
3.5 The system should be capable of fire
control or suppression under a wide variety of fire loading, fuel arrangement,
room geometry and ventilation conditions.
3.6 The system and equipment should be suitably designed to
withstand ambient temperature changes, vibration, humidity, shock, impact,
clogging and corrosion normally encountered in ships.
3.7 The system and its components should be designed
and installed in accordance with international standards acceptable to the
Organization1, and manufactured and tested to
the satisfaction of the Administration in accordance with the requirements given
in appendices 1 and 2 to these guidelines.
3.8 There should be not less than two
sources of power for the system. Where the sources of power for the pump are
electrical, these should be a main generator and an emergency source of power.
One supply for the pump should be taken from the main switchboard, and one
from the emergency switchboard by separate feeders reserved solely for that
purpose. The feeders should be so arranged as to avoid galleys,
machinery spaces and other enclosed spaces of high fire risk except in so far
as it is necessary to reach the appropriate switchboards, and should be run to
an automatic changeover switch situated near the sprinkler pump. This switch
should permit the supply of power from the main switchboard so long as a
supply is available there from, and be so designed that upon failure of that
supply it will automatically change over to the supply from the emergency
switchboard. The switches on the main switchboard and the emergency
switchboard should be clearly labelled and normally kept closed. No other
switch should be permitted in the feeders concerned. One of the sources of
power supply for the system should be an emergency source. Where one of the
sources of power for the pump is an internal combustion engine, it should, in
addition to complying with the provisions of the FSS Code, chapter 8,
paragraph 2.4.3, be so situated that a fire in any protected space will not
affect the air supply to the machinery. Pump sets consisting of two diesel
engines each supplying at least 50% of the required water capacity are
considered acceptable if the fuel supply is adequate to operate the pumps at
full capacity for a period of 36 h on passenger ships and 18 h on cargo
3.9 The system should be provided
with a redundant means of pumping, including drivers, or otherwise supplying a
water-based extinguishing medium to the sprinkler system. The capacity of the
redundant means should be sufficient to compensate for the loss of any single
supply pump or alternative source.
Failure of any one component in the power and control
system should not result in a reduction of the automatic release capability or
reduction of sprinkler pump capacity by more than 50%. Hydraulic calculations
should be conducted to assure that sufficient flow and pressure are delivered
to the hydraulically most remote 140 m2 in the event of the failure
of any one component.
3.10 The system should be fitted with a permanent sea inlet and be
capable of continuous operation using seawater.
3.11 The piping system should be sized in accordance
with an hydraulic calculation technique.2
3.12 Sprinklers should be grouped
into separate sections. Any section should not serve more than two decks of one
main vertical zone.
3.13 Each section of sprinklers should be capable of being isolated
by one stop valve only. The stop-valve in each section should be readily
accessible in a location outside of the associated section or in cabinets
within stairway enclosures. The valve’s location should be clearly and
permanently indicated. Means should be provided to prevent the operation of
the stop-valves by an unauthorized person. Isolation valves used for service,
maintenance or for refilling of antifreeze solutions may be installed in the
sprinkler piping in addition to the section stop valves, if provided with a
means for giving a visual and audible alarm as required by paragraph 3.17.
Valves on the pump unit may be accepted without such alarms if they are locked
in the correct position.
3.14 Sprinkler piping should not be used for any other purpose.
sprinkler system water supply components should be outside category A
machinery spaces and should not be situated in any space required to be
protected by the sprinkler system.
3.16 A means for testing the automatic operation of the system
for assuring the required pressure and flow should be provided.
3.17 Each sprinkler section should be provided
with a means for giving a visual and audible alarm at a continuously manned
central control station within one minute of flow from one or more sprinklers, a
check valve, pressure gauge, and a test connection with a means of drainage.
3.18 A sprinkler control plan
should be displayed at each centrally manned control station.
3.19 Installation plans
and operating manuals should be supplied to the ship and be readily available
on board. A list or plan should be displayed showing the spaces covered and
the location of the zone in respect of each section. Instructions for testing
and maintenance should also be available on board. The maintenance
instructions should include provisions for a flow test of each section at
least annually to check for possible clogging or deterioration in the
Sprinklers should have fast response characteristics as defined in ISO standard
3.21 In accommodation
and service spaces the sprinklers should have a nominal temperature rating of
57°C to 79°C, except that in locations such as drying rooms, where high ambient
temperatures might be expected, the nominal temperature may be increased by not
more than 30° C above the maximum deckhead temperature.
3.22 Pumps and alternative
supply components should be capable of supplying the required flow rate and
pressure for the space with the greatest hydraulic demand. For the purposes of
this calculation, the design area used to calculate the required flow and
pressure should be the deck area of the most hydraulically demanding space,
separated from adjacent spaces by A-class divisions. The design area need not
exceed 280 m2. For application to a small ship with a total
protected area of less than 280 m2, the Administration may specify
the appropriate area for sizing of pumps and alternate supply
3.23 The nozzle location, type of nozzle,
and nozzle characteristics should be within the tested limits determined by
the fire test procedures in appendix 2 to provide fire control or suppression
as referred to in paragraph 3.2.
3.24 For atriums with intermediate level
deck openings exceeding 100 m2, ceiling mounted sprinklers are not
3.25 The system should be designed in
such a way that during a fire occurrence, the level of protection provided to
those spaces unaffected by fire is not reduced.
3.26 A quantity of spare water mist
nozzles should be carried for all types and ratings installed on the ship as
Total number of
Required number of
|300 to 1000||12|
The number of spare nozzles of any type need not exceed
the total number of nozzles installed of that type.
3.27 Any parts of the system which may be
subjected to freezing temperatures in service should be suitably protected
1 Pending the development of
international standards acceptable to the Organization, ational standards as
prescribed by the Administration should be applied.
2 Where the Hazen-Williams Method is used, the
following values of the friction factor "C" for different pipe types which may
be considered should apply:
|Black or galvanized mild steel||120|
|Copper and copper alloys||150|