11.4.1 Ships in which the
carriage of flammable products is intended should be fitted with fixed
dry chemical powder type extinguishing systems for the purpose of
fighting fire on the deck in the cargo area and bow or stern cargo
handling areas if applicable. The system and the dry chemical powder
should be adequate for this purpose and satisfactory to the Administration.
11.4.2 The system should
be capable of delivering powder from at least two hand hose lines
or combination monitor/hand hose lines to any part of the above-deck
exposed cargo area including above-deck product piping. The system
should be activated by an inert gas such as nitrogen, used exclusively
for this purpose and stored in pressure vessels adjacent to the powder
containers.
11.4.3 The system for use
in the cargo area should consist of at least two independent self-contained
dry chemical powder units with associated controls, pressurizing medium
fixed piping, monitors or hand hose lines. For ships with a cargo
capacity of less than 1,000 m3 only one such unit need
be fitted, subject to approval by the Administration. A monitor should
be provided and so arranged as to protect the cargo loading and discharge
manifold areas and be capable of actuation and discharge locally and
remotely. The monitor is not required to be remotely aimed if it can
deliver the necessary powder to all required areas of coverage from
a single position. All hand hose lines and monitors should be capable
of actuation at the hose storage reel or monitor. At least one hand
hose line or monitor should be situated at the after end of the cargo
area.
11.4.4 A fire-extinguishing
unit having two or more monitors, hand hose lines, or combinations
thereof, should have independent pipes with a manifold at the powder
container, unless a suitable alternative means is provided to ensure
proper performance as approved by the Administration. Where two or
more pipes are attached to a unit the arrangement should be such that
any or all of the monitors and hand hose lines should be capable of
simultaneous or sequential operation at their rated capacities.
11.4.5 The capacity of a
monitor should be not less than 10kg/s. Hand hose lines should be
non-kinkable and be fitted with a nozzle capable of on/off operation
and discharge at a rate not less than 3.5 kg/s. The maximum discharge
rate should be such as to allow operation by one man. The length of
a hand hose line should not exceed 33 m. Where fixed piping is provided
between the powder container and a hand hose line or monitor, the
length of piping should not exceed that length which is capable of
maintaining the powder in a fluidized state during sustained or intermittent
use, and which can be purged of powder when the system is shut down.
Hand hose lines and nozzles should be of weather-resistant construction
or stored in weather-resistant housing or covers and be readily accessible.
11.4.6 A sufficient quantity
of dry chemical powder should be stored in each container to provide
a minimum 45 seconds discharge time for all monitors and hand hose
lines attached to each powder unit. Coverage from fixed monitors should
be in accordance with the following requirements:
| Capacity of fixed monitors
(kg/s) each
|
10
|
25
|
45
|
| Maximum distance of coverage(m)
|
10
|
30
|
40
|
Hand hose lines should be considered
to have a maximum effective distance of coverage equal to the length
of hose. Special consideration should be given where areas to be protected
are substantially higher than the monitor or hand hose reel locations.
11.4.7 Ships fitted with
bow or stern loading and discharge arrangements should be provided
with an additional dry chemical powder unit complete with at least
one monitor and one hand hose line complying with the requirements
of 11.4.1, 11.4.2, 11.4.3, 11.4.4, 11.4.5 and 11.4.6. This additional unit should be
located to protect the bow or stern loading and discharge arrangements.
The area of the cargo line forward or aft of the cargo area should
be protected by hand hose lines.