Interpretations of Vague Expressions, other Vague Wording and References in the Fire Safety Systems (FSS) Code

FSS Code		Interpretation or reference
Chapter	Paragraph	Application
3	2.1.1.4	Personal Equipment Reference is made to IEC Publication 60079- Electrical Apparatus for Explosive Gas Atmospheres.
4	-	Fire Extinguishers Reference is made to resolution A.951(23) - improved Guidelines for marine portable fire extinguishers, as amended by resolution A.951(23).
4	2.1.1.2	Equivalents of fire extinguishers Reference is made to the international standard on fire protection equipment - portable fire extinguisher - performance and construction, to be developed by ISO (ISO/DIS 7156E).
4	3.1.2	Recharging of spare charges Partially emptied extinguishers should also be recharged.
5	2.1.1.1	Separation of spaces Two spaces can be considered as separated spaces where fire divisions as required by regulations 9.2.2, 9.2.3 and 9.2.4, as appropriate, or divisions of steel are provided between them.
5	2.1.1.3	Means for checking the quantity of medium in containers Means for checking the quantity of medium in containers should be so arranged that it is not necessary to move the containers completely from their fixing position. This is achieved, for instance, by providing hanging bars above each bottle row for a weighing device or by using suitable surface indicators.
5	2.1.3.2	Certain spaces for which the automatic warning of release of the extinguishing medium is required Ordinary cargo holds need not comply with regulation 2.1.3.2. However, ro-ro cargo spaces, holds in container ships equipped for integrated reefer containers and other spaces where personnel can be expected to enter and where the access is therefore facilitated by doors or manway hatches should comply with the above regulation.
5	2.2	Low pressure CO₂ systems Where a low pressure CO₂ system is fitted to comply with this regulation, the following applies: 1 The system control devices and the refrigerating plants should be located within the same room where the pressure vessels are stored. 2 The rated amount of liquid carbon dioxide should be stored in vessel(s) under the working pressure in the range of 1.8 to 2.2 N/mm². The normal liquid charge in the container should be limited to provide sufficient vapour space to allow for expansion of the liquid under the maximum storage temperatures than can be obtained corresponding to the setting of the pressure relief valves but should not exceed 95% of the volumetric capacity of the container. 3 Provision should be made for: pressure gauge; high pressure alarm: not more than setting of the relief valve; low pressure alarm: not less than 1.8 N/mm²; branch pipes with stop valves for filling the vessel; discharge pipes; liquid CO² level indicator, fitted on the vessel(s); two safety valves. 4 The two safety relief valves should be arranged so that either valve can be shut off while the other is connected to the vessel. The setting of the relief valves should not be less than 1.1 times working pressure. The capacity of each valve should be such that the vapours generated under fire condition can be discharged with a pressure rise not more than 20% above the setting pressure. The discharge from the safety valves should be led to the open. 5 The vessel(s) and outgoing pipes permanently filled with carbon dioxide should have thermal insulation preventing the operation of the safety valve in 24 hours after de-energizing the plant, at ambient temperature of 45°C and an initial pressure equal to the starting pressure of the refrigeration unit. 6 The vessel(s) should be serviced by two automated completely independent refrigerating units solely intended for this purpose, each comprising a compressor and the relevant prime mover, evaporator and condenser. 7 The refrigerating capacity and the automatic control of each unit should be so as to maintain the required temperature under conditions of continuous operation during 24 hours at sea temperatures up to 32°C and ambient air temperatures up to 45°C. 8 Each electric refrigerating unit should be supplied from the main switchboard busbars by a separate feeder. 9 Cooling water supply to the refrigerating plant (where required) should be provided from at least two circulating pumps one of which being used as a stand-by. The stand-by pump may be a pump used for other services so long as its use for cooling would not interfere with any other essential service of the ship. Cooling water should be taken from not less than two sea connections, preferably one port and one starboard. 10 Safety relief devices should be provided in each section of pipe that may be isolated by block valves and in which there could be a build-up of pressure in excess of the design pressure of any of the components. 11 The piping system should be designed in such a way that the CO₂ pressure at the nozzles should not be less than 1 N/mm². 12 Audible and visual alarms should be given in a central control station when: the pressure in the vessel(s) reaches the low and high values according to 2; any one of the refrigerating units fails to operate; the lowest permissible level of the liquid in the vessels is reached. 13 If the system serves more than one space, means for control of discharge quantities of CO₂ should be provided, e.g. automatic timer or accurate level indicators located at the control position(s). 14 If a device is provided which automatically regulates the discharge of the rated quantity of carbon dioxide into the protected spaces, it should be also possible to regulate the discharge manually.
7	2.1.1.2	Areas for increased application rates An indication of areas for which increased application rates may be required is given below:
		Protected Area	Application rate
		Boiler fronts or roof, firing areas, oil fuel units, centrifugal separators (not oily water separators), oil purifiers, and clarifiers.	20 l /min/m²
		Hot oil fuel pipes near exhausts or similar heated surfaces on main or auxiliary diesel engines	10 l /min/m²
8	2.1.1	Dry pipe systems in saunas For the definition of "dry pipe system" see resolution A.800(19), Annex, paragraph 2.3.
8	2.5.2.3	Definition of nominal area Nominal area is defined as being the gross, horizontal projection of the area to be covered.
9	2.4.1.1	Acceptable activating arrangements The following arrangement may be acceptable to: .1 activate a paging system; .2 activate the fan stops; .3 activate the closure of fire doors; .4 activate the closure of fire dampers; .5 activate the sprinkler system; .6 activate the smoke extraction system; and .7 activate the low-location lighting system.
9	2.1.4	Relevant definitions Loop means electrical circuit linking detectors of various sections in a sequence and connected (input and output) to the indicating unit(s). Zone address identification capability means a system with individually identifiable fire detectors.
9	2.1.3	Testing of detectors within cold spaces Detectors installed within cold spaces such as refrigerated compartments should be tested according to IEC Publication 60068-2-1 - Section one - Test Aa.
10	2.1.2	Calculation of intervals The interval (I) should depend on the number of scanning points (N) and the response time of the fans (T). (See interpretation of paragraph 2.2.2 chapter 10 below.) With a 20 % allowance: However, the maximum allowable interval should not exceed 120 s (x _max = 120 s).
10	2.2.2	Response time for fans Depending on the capacity of the fans and the length of system piping the maximum response time of the fans in combination with the system piping should be around 15 s.
12	2.2.2.1	Heating of diesel driven power sources and other means of starting 1 If the room for the diesel driven power source is not heated, the diesel driven power source for the pump should be fitted with electric heating of cooling water or lubricating oil. 2 The other means of starting include those by compressed air, electricity, or other sources of stored energy, hydraulic power or starting cartridges.
13	2.2.4	Size of landings and intermediate landings If landings can be entered directly via entrance doors, situated in stairway enclosures, the area of such landings should comply with the requirements of paragraph 2.2.4 of chapter 13. However, if landings cannot be entered by entrance doors, such landings should be considered as intermediate landings which should comply with the capacity requirements as given in paragraph 2.3.1 of chapter 13.
14	2.1.3	Capacity, use and handling of deck foam systems A common line for fire main and deck foam line can only be accepted provided it can be demonstrated that the hose nozzles can be effectively controlled by one person when supplied from the common line at a pressure needed for operation of the monitors. Additional foam concentrate should be provided for operation of 2 nozzles for the same period of time required for the foam system. The simultaneous use of the minimum required jets of water should be possible on deck over the full length of the ship, in the accommodation, service spaces, control stations and machinery spaces.
14	2.3.2.3	Foam systems positions of aft monitors The port and starboard monitors required by this paragraph may also be located in the cargo area above oil bunker tanks adjacent to cargo tanks if capable of protecting the deck below and aft of each other.
14	2.3.3	Application to tankers This paragraph applies to all tankers regardless of their size.
15	2.3.2.7	Arrangements for isolation of inert gas supply mains and cargo piping systems As a guide, the effective isolation required by this paragraph may be achieved by the two arrangements shown in figures 1 and 2 of chapter 15 and paragraph 2.3.2.7 in the Appendix of this circular.