3 - Principal requirements for the system
3.1 The system should be capable of manual
release, and may be arranged for automatic release.
3.2 For helidecks the foam system should
contain at least two fixed foam monitors or deck integrated
foam nozzles. In addition, at least two hose reels fitted
with a foam-making branch pipe and non-collapsible hose
sufficient to reach any part of the helideck should be
provided. The minimum foam system discharge rate should be
determined by multiplying the D-value area by 6
l/min/m2. The minimum foam system
discharge rate for deck integrated foam nozzle systems
should be determined by multiplying the overall helideck
area by 6 l/min/m2. Each monitor should
be capable of supplying at least 50 per cent of the minimum
foam system discharge rate, but not less than 500
l/min. The minimum discharge rate of each hose reel
should be at least 400 l/min. The quantity of foam
concentrate should be adequate to allow operation of all
connected discharge devices for at least 5 min.
3.3 Where foam monitors are installed, the
distance from the monitor to the farthest extremity of the
protected area should be not more than 75 per cent of the
monitor throw in still air conditions.
3.4 For helicopter landing areas, at least
two portable foam applicators or two hose reel foam stations
should be provided, each capable of discharging a minimum
foam solution discharge rate, in accordance with the
following table.
Category
|
Helicopter overall length
(D- value)
|
Minimum foam
solution
discharge
rate
(l/min)
|
| H1 |
up to but not
including 15 m |
250 |
| H2 |
from 15 m up to but
not including 24 m |
500 |
| H3 |
from 24 m up to but
not including 35 m |
800 |
The quantity of foam concentrate should be
adequate to allow operation of all connected discharge
devices for at least 10 min. For tankers fitted with a deck
foam system, the Administration may consider an alternative
arrangement, taking into account the type of foam
concentrate to be used.
3.5 Winching areas should comply with SOLAS
regulation II-2/18.2.2.
3.6 Manual release stations capable of
starting necessary pumps and opening required valves,
including the fire main system, if used for water supply,
should be located at each monitor and hose reel. In
addition, a central manual release station should be
provided at a protected location. The foam system should be
designed to discharge foam with nominal flow and at design
pressure from any connected discharge devices within 30 s of
activation.
3.7 Activation of any manual release station
should initiate the flow of foam solution to all connected
hose reels, monitors, and deck integrated foam nozzles.
3.8 The system and its components should be
designed to withstand ambient temperature changes,
vibration, humidity, shock impact and corrosion normally
encountered on the open deck, and should be manufactured and
tested to the satisfaction of the Administration.
3.9 A minimum nozzle throw of at least 15 m
should be provided with all hose reels and monitors
discharging foam simultaneously. The discharge pressure,
flow rate, and discharge pattern of deck integrated foam
nozzles should be to the satisfaction of the Administration,
based on tests that demonstrate the nozzle's capability to
extinguish fires involving the largest size helicopter for
which the helideck is designed.
3.10 Monitors, foam-making branch pipes,
deck integrated foam nozzles and couplings should be
constructed of brass, bronze or stainless steel. Piping,
fittings and related components, except gaskets, should be
designed to withstand 925ºC.
3.11 The foam concentrate should be
demonstrated effective for extinguishing aviation fuel spill
fires and should conform to performance standards not
inferior to those acceptable to the
Organization1. Where the
foam storage tank is on the exposed deck, freeze protected
foam concentrates should be used, if appropriate, for the
area of operation.
3.12 Any equipment installed within the
take-off and approach obstacle free sector should not exceed
a height of 0.25 m. Any equipment installed in the limited
obstacle sector should not exceed the height permitted for
objects in this area.
3.13 All manual release stations, monitor
foam stations, hose reel foam stations, hose reels and
monitors should be provided with a means of access that does
not require travel across the helideck or helicopter landing
area.
3.14 Oscillating monitors, if used, should
be preset to discharge foam in a spray pattern and have a
means of disengaging the oscillating mechanism to allow
rapid conversion to manual operation.
3.15 If a foam monitor with flow rate up to
1,000 l/min is installed, it should be equipped
with an air-aspirating nozzle. If a deck integrated nozzle
system is installed, then the additionally installed hose
reel should be equipped with an air-aspirating handline
nozzles (foam branch pipes). Use of non air-aspirating foam
nozzles (on both: monitors and the additional hose reel) is
permitted only where foam monitors with a flow rate above
1,000 l/min are installed. If only portable foam applicators
or hose reel stations are provided, these should be equipped
with an air-aspirating handline nozzles (foam
branchpipes).
1
Refer to the International Civil Aviation Organization
Airport Services Manual, part 1, Rescue and Fire-Fighting,
chapter 8, Extinguishing Agent Characteristics, paragraph
8.1.5, foam Specifications table 8-1, level "B", or to the
Revised Guidelines for the performance and testing criteria,
and surveys of foam concentrates for fixed
fire-extinguishing systems (MSC.1/Circ.1312)