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.
3.3 The 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 2.3.2.1. 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 Organizationfootnote, 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 ships.
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.footnote
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.
3.15 The 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 discharge piping.
3.20 Sprinklers should have fast response characteristics
as defined in ISO Standard 6182/1.
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 components.
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 required.
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 follows:
|
Total number of nozzles
|
Required number of spares
|
| < 300
|
6
|
| 300 to 1000
|
12
|
| > 1000
|
24
|
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 against
freezing.