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Chapter 10 - Fire Safety.

Application.  ^

1001. The requirements of this Chapter define the minimum fire safety standards to be applied to A.C.V's in which fuel with a flash point, as determined by an approved closed cup method, in excess of 38°C is used. The use of fuels with lower flash points may require additional provisions.

Definitions.  ^

1002. a) Designated Fire Zone - any space containing machinery using fuel, or any space where electrical equipment is operating in close proximity to fuel system components or in an atmosphere potentially capable of promoting combustion or explosion, is defined as a Designated Fire Zone.

b) Incombustible - a material which neither burns nor gives off flammable vapours in sufficient quantity for self-ignition when heated to 750°C, as determined by an acceptable test method, is defined as incombustible. All other materials are regarded as combustible.

c) Standard Fire Test - a test in which representative specimens of structure, which should be of not less than 4.65 sq.m. in area, are exposed in a test furnace to temperatures approximating to the following time-temperature relationship:-

After 5 minutes - 538°C.

After 10 minutes - 704°C.

After 30 minutes - 843°C.

After 60 minutes - 927°C.

d) Low Flame Spread - a material which, when subjected to an appropriate approved test, adequately restricts the spread of flame. Such a test as Test No. Ul-723 of the Underwriters Laboratories Inc. (U.S.A.) and conforming to Underwriters Laboratories of Canada Standard S.102, would be acceptable. When so tested, the flame spread rating shall not exceed 20.

Structure  ^

1003. The hull of the vehicle should be constructed of incombustible material. Where such material is not used, it shall be treated or protected by means which shall be specifically approved subject to satisfactory results of representative fire testing.

1004. Divisions forming boundaries between a Designated Fire Zone and other enclosed spaces within the vehicle shall be of incombustible material, or shall be insulated in the Designated Fire Zone such that they will prevent the passage of smoke and flame without collapse for the greater of 30 minutes or 3 times the demonstrated evacuation time of the total complement into survival craft plus 7 minutes. Other boundaries shall be of similar fabrication to the maximum extent possible, and shall as a minimum be capable of preventing the passage of smoke, flame and gas from the Designated Fire Zone for sufficient time to contain, in the required concentration and for the required time, two successive discharges of fixed or portable fire extinguishers provided for protection of the Zone.

1005. Divisions designed to comply with Section 1004 and which are not constructed of steel shall be insulated so that during the first 30 minutes of the standard fire test, the core temperature does not exceed 200^°C above ambient. All divisions shall be insulated such that the temperature of the surface on the remote side after 30 minutes of the standard fire test does not exceed 139^° C above ambient; at locations where persons may come into contact with the remote surface, the surface temperature shall not exceed 70^°C after 30 minutes of the standard fire test. Insulation shall not give off toxic vapours.

1006. All equipment, components, pipes and cables within, or attached to the inside surfaces of boundaries of, Designated Fire Zones shall be of incombustible material; electrical equipment shall additionally be designed and constructed so as to prevent the generation of sparks or flashes.

1007. No penetration of a boundary of a Designated Fire Zone shall reduce the fire integrity of that boundary. Where penetrations are essential to provide access to the atmosphere for the normal operation of equipment within the Zone, such penetrations shall be provided with fire resistant closings which may be remotely operated and which comply with the requirements of Section 1004.

1008. All material within a Designated Fire Zone, and elsewhere in the vehicle where it may become contaminated with flammable fluids, shall be impermeable to such fluids.

1009. All furnishings, insulation, trim, flooring and facing materials shall be of at least low flame-spread rating, or be treated to have an equivalent rating.

1010. Structural fire protection as appropriate to the vehicle layout may be required for compartments other than Designated Fire Zones, from which the vehicle may be controlled.

Fire Detection.  ^

1011. All Designated Fire Zones shall be provided with remote-indicating detection equipment providing indication at the crew station from which the vehicle is normally manoeuvred. The arrangement and type of detection equipment shall provide the most effective indication of a potential fire hazard in the Zone being protected, and the equipment installed in a Designated Fire Zone shall not be associated with similar equipment installed in other Designated Fire Zones or other spaces. Indication shall be both visual and audio.

1012. All detection systems shall be re-settable after they have provided a hazard indication, and shall incorporate a test facility to indicate system integrity and serviceability at the station from which the vehicle is normally manoeuvred.

1013. All fire detection systems shall be capable of efficient operation in the event of total failure of electrical power generation, and they shall be permanently connected to a source of electrical power at all times that such power is available to or in the vehicle.

1014. Fire detection systems shall be intalled to withstand the acceleration loadings quoted in Section 506 without affecting their efficient operation.

Fire Suppression.  ^

1015. All Designated Fire Zones shall be provided with remotely controlled fire suppression systems, with controls provided at least at the crew station from which the vehicle is normally manoeuvred. The type, quantity and distribution of fire extinguishant, and the arrangement of controls, shall be approved. In submitting data for approval, the designer shall include all appropriate calculations. A fire extinguishant discharge and retention test may be required.

1016. No fire extinguishant storage container shall be installed in a Designated Fire Zone; installation arrangements shall ensure that the storage containers are maintained within approved limits of environmental conditions appropriate to the extinguishant, as determined by the National Fire Protection Agency Standard Codes.

1017. All fire extinguishant storage containers shall, for extinguishers manufactured in Canada, bear the approval label of Underwriter's Laboratory of Canada; extinguishers manufactured in the United Kingdom or United States shall be approved for marine use by the British Department of Trade and Industry or by the United States Coast Guard respectively. They shall be installed so that the quantity contained may be readily determined.

1018. In spaces designed for passengers accommodation, and in crew compartments, approved portable fire extinguishers shall be provided in readily visible and accessible stowages clearly marked; the quantity, type and distribution shall be approved, based upon the vehicle layout and the space to be protected.

1019. All fire extinguishant containers shall be stowed such that, when subject to the acceleration loadings quoted in Section 506, they will be retained and the loading will not affect their efficient operation.

1020. In vehicles where boundaries of Designated Fire Zones contain openings, the fire extinguishing system shall be arranged so that extinguishant cannot be discharged until all such openings are closed.

1021. Designated Fire Zones containing an engine or part of an engine used for vehicle lift or propulsion shall be provided with means of discharging a second fire extinguisher. Where this extinguisher is provided primarily for the protection of another space, it's alternate selection shall require a distinctive action. Where practical, use of a portable extinguisher may be approved for the second discharge, in which case a suitable fire-resistant frangible closure in the fire-resistant boundary shall be provided.

1022. Electrical circuits associated with activating the discharge of fire extinguishant shall have a test facility provided, operable at the crew station from which the vehicle is normally manoeuvred.

1023. All electrical circuits associated with activating the discharge of fire extinguishant shall be capable of efficient operation in the event of total failure of electrical power generation, and they shall be permanently connected to an electrical source of power at all times that such power is available to or in the vehicle.

1024. All indicators, test facilities and controls associated with fire detection and fire suppression systems shall be provided at a station or stations at which crew members other than the operator of navigational radar are stationed in their normal duties. In vehicle designs where machinery in Designated Fire Zones may be operated from local controls, fire suppression system controls shall be positioned immediately adjacent to the exit from the Zone, on the external face of the fire-resistant boundary. Such controls shall include all those necessary to ensure efficient operation of the fire extinguishant discharge system.

1025. Any multiple installation of fire extinguishant controls in compliance with Section 1024 shall be so arranged that the controls at all stations are effective at all times.

Supplementary Fire Safety Measures.  ^

1026. Where the designer proposes to use materials containing chemical treatments or mechanical applications of materials intended to improve the fire suppression or extinguishing properties of the material, he shall submit all relevant data and test results from the manufacturer of the protective treatment. Upon review of these data, additional testing may be required. No treatment or application which depends for it's effectiveness upon the emission of noxious or toxic vapours will be considered for use in a compartment which may be occupied when the vehicle is in normal operation.

Fixed Fire Extinguishant Media.  ^

1027. Where gaseous media in the form of either carbon dioxide or a halogenated hydrocarbon are used, quantities shall be provided such that the following concentrations result from a single discharge into the space being protected:-

Carbon Dioxide - 30% of gross volume being protected.

Halon 1211 - 5 to 5.5% of net volume of space being protected.

Halon 1301 - 5 to 7% of net volume of space being protected.

Halon 2402 - to be provided on a mass per unit volume basis, between 0.20 kg/m³ and 0.30 kg/m³ net volume.

For the purposes of determining quantities required, volumes of media shall be calculated as follows:-

Carbon Dioxide - 0.56 m³/kg.

Halon 1211 - 0.14 m³/kg.

Halon 1301 - 0.16 m³/kg.

Additional guidance data relating to the design of fire suppression systems should be sought from the appropriate standard of the National Fire Protection Agency (NFPA).

1028. Systems shall be arranged so that discharges shall be substantially complete:-

For carbon dioxide - 85% of gas discharged within 2 minutes.

For halogenated hydrocarbons - liquid phase discharge complete within 20 seconds.

1029. Where other media are proposed for fixed fire extinguishing installations, full supporting data are to be provided by the designer, indicating that protection equivalent to that provided by Sections 1027 and 1028 will result.

Portable Fire Extinguishers.  ^

1030. Portable fire extinguishers when fully charged shall have a total weight of not more than 23 kg.

1031. Fire extinguishers containing water shall not be provided in spaces containing electrical equipment or components operating at voltages in excess of 55 volts.

1032. Fire extinguishers containing dry powder chemicals shall not be provided in compartments containing switchboards, open electrical connections or electronic equipment.

Doors and Exits.  ^

1033. Doors between passenger accommodation and spaces in the vehicle to which the crew may have access which are not required to be either fire-resistant or watertight shall be designed and installed so as to minimise the passage of smoke and vapours when closed.

1034. Doors and personnel accesses in fire-resistant boundaries shall be hinged to open outwards from Designated Fire Zones to which they provide access, and shall have effective means of opening and of securing to preserve fire-resistant integrity, operable from both outside and inside the space.

Special Category Spaces.  ^

1035. A special category space is an enclosed space provided for the carriage of motor vehicles with fuel in their tanks for their own propulsion, into and from which they may be driven and to which passengers have controlled access.

1036. Special category spaces shall be provided either with a fixed fire extinguishing system or with adequate semi-portable fire extinguishers, subject to a minimum of two such extinguishers being provided.

1037. The design and installation of all fire safety provisions made for the protection of special category spaces, including alarms and controls and such provisions, shall be determined and approved taking into consideration the volume and arrangement of the space.

1038. Where the discharge of fixed fire extinguishant media may result in significant accumulation of liquids in the space, adequate arrangements for drainage shall be provided.

1039. All electrical equipment installed in a special category space shall be certified safe for operation in explosive vapour/air mixtures, and all electrical cables shall be contained in protective conduits. No electrical equipment shall be installed less than 0.45 m. above the deck of the space.

1040. All doors and exits for passengers and crew members giving access to or from the special category space shall be provided with effective means of securing in the closed position, operable from both inside and outside the space.

1041. Each special category space shall be provided with two-way communication with the crew station from which the vehicle is normally manoeuvred; the arrangement of such communication shall be approved.

Fire Safety Ventilation  ^

1050. Effective forced ventilation shall be provided for all spaces in which flammable fluids or vapours may accumulate. Where such spaces contain machinery or equipment which may be potential sources of ignition, the design shall provide adequate forced ventilation, or means thereof, to ensure that the space is adequately vented prior to start-up of machinery or equipment.

1051. All ventilation discharges shall be overboard and sited to prevent as far as practical the re-ingestion of vapour into the vehicle or cushion.

1052. Ventilation openings in the boundaries of Designated Fire Zones shall be kept to a minimum consistent with safe operation, and shall be provided with externally operated effective and secure fire-resistant closings. Provision to the maximum extent practical shall be made for their remote operation such that the discharge of fire extinguishant is inhibited until closings are in place.

1053. All ventilation fans controls should be from outside the space they serve, and additionally from inside where the space may be occupied; failure of electrical power to ventilation fans shall be indicated at the crew station from which the vehicle is normally manoeuvred.

1054. Any ventilation duct or trunking passing through a Designated Fire Zone boundary shall, within the Designated Fire Zone, be either:-

1. Constructed and insulated to the same standard as the boundary, or
   
   
2. Provided with effective closures at the fire resistant boundary having identical fire resistant properties as the boundary.

1055. Special category spaces shall be provided with ventilation giving a minimum of 10 complete changes of air per hour; indication of failure of power to any fan providing this ventilation shall be provided at the crew station from which the vehicle is normally manoeuvred.

1056. In spaces where flammable liquids or vapours may accumulate and where ventilation is provided by electrical means, all components of the electrical ventilation system within the space shall be of a type certified safe for operation in the particular atmosphere, i.e. "explosion proof", "intrinsically safe", "increased safety".

Materials - Fire Safety.  ^

1060. No materials used in the construction, furnishing or decoration of any spaces normally accessible to passengers or crew members performing their duties when an A.C.V. is operating shall emit toxic smoke or vapours when exposed to temperatures in excess of 60°C.

1061. The use of materials which do emit toxic smoke or vapours when heated above 60°C is to be minimised so far as is practicable and shall be restricted to spaces remote and sealed from spaces to which passengers and crew members have access during normal vehicle operation.

1062. Material manufacturer's or fabricator's data, which may include reports of tests by competent agencies, relating to flammability and emissions resulting from exposure to heat, may be required for any material or material treatment used in the fabrication, furnishings and finishings of a vehicle.

1063. All materials used for thermal and acoustic insulation shall, to the maximum extent practicable, be non-combustible, and shall not give off toxic fumes or vapours when heated in excess of 60°C.

1064. Low density foam materials used for buoyancy shall be non-combustible or self-extinguishing, and their installation shall be shielded to the maximum extent practicable from potential sources of ignition, and from possible contamination by flammable fluids.

Hot exhausts - Fire Protection.  ^

1070. Where any duct or pipe carrying the exhaust gases of engines, galley equipment or other components, passes through or runs along any vehicle structure, bulkhead or plating, the duct or pipe and the structural component are to be adequately separated and shielded with non-combustible material and thermal insulation. When penetrating, the duct or pipe is to be adequately supported to maintain separation; all exhaust runs should be kept as short as practical, supported to prevent distortion, and provided with such expansion measures as may be required to minimise stresses due to thermal expansion. All outlets carrying noxious or toxic fumes, or gases with temperature in excess of 40°C shall have adjacent warning notices.

Appendix to Chapter 10 ^

A. Fire Extinguishant Media.  ^

Generally accepted fire extinguishant media are:-

Liquid - water, foam.

Gaseous - carbon dioxide, halogenated hydrocarbons

(BCF, BCM, Halons)

Solid - dry chemical powder.

No liquid medium will generally be permitted in spaces where the extinguishant may contact electrical equipment; exceptionally, liquid extinguishant may be permitted if there is no possibility of it coming into contact with electrical equipment operating at voltages of 55 volts or more.

Gaseous media will not generally be permitted in any space which may contain occupants when the vehicle is in operation. When designing fixed fire suppression systems, it is highly desirable to consult with fire safety specialists; the effectiveness, in particular of halogenated hydrocarbons, is sensitive to the rapidity with which the required concentration can be achieved.

Delays may not only reduce the effectiveness, but can also lead to decomposition of the extinguishant to produce highly toxic products.

Dry chemical powder extinguishants, unless specially formulated, promote corrosion particularly of electrical contacts, leading to delayed electrical equipment failures. Due to their nature, they may permeate widely and are difficult to completely clean up; their use near electrical or electronic equipment is therefore not generally permitted. A further problem with dry chemical extinguishant is the tendency to "cake" under dynamic conditions, which may severely restrict it's effective discharge when required.

B. Material Treatment to Improve Fire Resistance.  ^

Glass reinforced plastics may attain satisfactory fire resistant properties by one of two methods - the resin may be specially formulated to provide fire-resistant properties, or additives may be mixed with the resin. Designers should consult with resin manufacturers to determine how fire resistance is provided, and should ensure that provision of fire resistance is maintained over the life expectancy of the hull or structure considered, and that structural strength of the final material is not adversely affected by the fire resistant treatment.

The use of intumescent paints or treatments, which rely for the provision of fire protection on the release of fire-suppressant vapours in the presence of heat, will only be permitted in spaces normally unattended during vehicle operation. Where they are permitted, full instructions relating to the maintenance of the treatment are to be provided in vehicle servicing and maintenance manuals.

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