Ingangsdatum: 08-06-1998
Geldig tot en met: 03-06-2008
General1 Fixed gas fire-extinguishing systems for
use in machinery spaces of category A and cargo pump-rooms equivalent to
fire-extinguishing systems required by SOLAS regulations II-2/7 and II-2/63 should prove
that they have the same reliability which has been identified as significant for the
performance of fixed gas fire-extinguishing systems approved under the requirements of
SOLAS regulation II-2/5. In addition, the system should be shown by test to have the
capability of extinguishing a variety of fires that can occur in a ship's engine-room.
Principal requirements
2 All requirements of
SOLAS regulations II-2/5.1, 5.3.1, 5.3.2 to 5.3.3, except as modified by these
guidelines, should apply.
3 The minimum
extinguishing concentration should be determined by a cup burner test acceptable to the
Administration. The design concentration should be at least 20% above the minimum
extinguishing concentration. These concentrations should be verified by full-scale
testing described in the test method, as set out in the appendix.
4 For systems using halocarbon clean agents, 95% of the design
concentration should be discharged in 10 s or less. For inert gas systems, the discharge
time should not exceed 120 s for 85% of the design concentration.
5 The quantity of extinguishing agent for the protected space
should be calculated at the minimum expected ambient temperature using the design
concentration based on the net volume of the protected space, including the casing.
5.1 The net volume of a protected space is that
part of the gross volume of the space which is accessible to the free extinguishing
agent gas.
5.2 When calculating the net
volume of a protected space, the net volume should include the volume of the bilge, the
volume of the casing and the volume of free air contained in air receivers that in the
event of a fire is released into the protected space.
5.3 The objects that occupy volume in the protected space should be
subtracted from the gross volume of the space. They include, but are not necessarily
limited to:
- auxiliary machinery;
- boilers;
- condensers;
- evaporators;
- main engines;
- reduction gears;
- tanks; and
- runks.
5.4
Subsequent modifications to the protected space that alter the net volume of the space
shall require the quantity of extinguishing agent to be adjusted to meet the
requirements of this paragraph and paragraph 6.
6 No fire suppression agent should be used which is carcinogenic, mutagenic,
or teratogenic at concentrations expected during use. No agent should be used in
concentrations greater than the cardiac sensitization NOAEL (No Observed Adverse Effect
Level), without the use of controls as provided in SOLAS regulations II-2/5.2.5.1 and
5.2.5.2. In no case should an agent be used above its LOAEL (Lowest Observed Adverse
Effects Level) nor ALC (Approximate Lethal Concentration) calculated on the net volume
of the protected space at the maximum expected ambient temperature.
7 The system and its components should be suitably designed
to withstand ambient temperature changes, vibration, humidity, shock, impact, clogging,
and corrosion normally encountered in machinery spaces or cargo pump-rooms in ships.
8 The system and its components should be
designed and installed in accordance with international standards acceptable to the
Organization
1 and manufactured and tested to the satisfaction of the
Administration. As a minimum, the design and installation standards should cover the
following elements:
- safety:
- toxicity;
- noise, nozzle
discharge; and
- decomposition products;
- storage container design and arrangement:
- strength requirements;
- maximum/minimum fill density, operating temperature range;
- pressure and weight indication;
- pressure relief; and
- agent identification and lethal requirements;
- agent supply, quantity, quality standards;
- pipe and fittings:
- strength, material, properties, fire resistance; and
- cleaning
requirements;
- valves:
- testing requirements;
- corrosion resistance; and
- elastomer compatibility;
- nozzles:
- height and area testing requirements; and
- corrosion
and elevated temperature resistance;
- actuation and control systems: - testing requirements; and - backup power
requirements;
- alarms and indicators:
- predischarge alarm, agent
discharge alarms as time delays;
- abort switches;
- supervisory
circuit requirements; and
- warning signs and audible and visual alarms
should be located outside each entry to the relevant space as appropriate;
- agent flow calculation:
- approval and testing of design calculation
method; and
- fitting losses and/or equivalent length;
- enclosure integrity and leakage requirements:
- enclosure leakage;
- openings; and
- mechanical ventilation interlocks;
- design concentration requirements, total flooding quantity;
- discharge time; and
- inspection, maintenance, and testing
requirements.
9 The nozzle type, maximum nozzle
spacing, maximum height and minimum nozzle pressure should be within limits tested to
provide fire extinction per the proposed test method.
10 Provisions should be made to ensure that escape routes which are exposed
to leakage from the protected space are not rendered hazardous during or after discharge
of the agent. Control stations and other locations that require manning during a fire
situation should have provisions to keep HF and HCl below 5 ppm at that location. The
concentrations of other products should be kept below concentrations considered
hazardous for the required duration of exposure.
11 Agent containers may be stored within a protected machinery space if the
containers are distributed throughout the space and the provisions of SOLAS regulation
II-2/5.3.3 are met. The arrangement of containers and electrical circuits and piping
essential for the release of any system should be such that in the event of damage to
any one power release line through fire or explosion in the protected space, i.e. a
single fault concept, at least five-sixths of the fire-extinguishing charge as required
by paragraph 5 of this annex can still be discharged having regard to the requirement
for uniform distribution of medium throughout the space. The arrangements in respect of
systems for spaces requiring less than 6 containers should be to the satisfaction of the
Administration.
12 A minimum agent hold time
of 15 min should be provided.
13 The release
of an extinguishing agent may produce significant over and under pressurization in the
protected space. Measures to limit the induced pressures to acceptable limits should be
provided.
14 For all ships, the
fire-extinguishing system design manual should address recommended procedures for the
control of products of agent decomposition. The performance of fire-extinguishing
arrangements on passenger ships should not present health hazards from decomposed
extinguishing agents, e.g., on passenger ships, the decomposition products should not be
discharged in the vicinity of muster (assembly) stations.
1 Until international standards are developed, national standards
acceptable to the Administration should be used. Available national standards include,
e.g., Standards of Australia, the United Kingdom and NFPA 2001.