1 . General indications
1.1 The terms and definitions used in the
following correspond to those of Chapter II-2 of SOLAS 74. The requirements of this IMO convention are applicable in principle. Additional requirements of the competent Administration may have to be observed.
1.2 Some principles on structural fire protection, together with particular requirements for offshore production/storage units, are given below. For details see also
– for ship - type units: Rules for Hull, Volume II, Section 22;
– for offshore installations such as column stabilized units: Rules for Machinery Installations, Volume 4, Section 10.
1.3 In special cases the fire protection
arrangements may differ from the regulations of this section, provided that the protection is considered to be equivalent, owing to appropriate measures having been taken. 1.4 Type "A", "B" and "C" Class divisions as well as the insulation materials, linings, ceilings, surface materials and not readily ignitable deck coverings shall be of approved type.
1.5 Drawings showing the general arrangement and the intended use of all spaces, and containing details on the planned structural fire protection arrangements as well as information about type, manufacturer and existing type approvals are to be submitted for approval.
1.6 Fire and blast walls: See 5.
2. Materials
2.1 The hull, decks, structural bulkheads, super structures and mooring structures are to be made of steel (see Section 4 and 5). Other equivalent material (Aluminium alloy suitably insulated) may be approved in particular cases, having in mind the risk of fire.
2.2 Components made from aluminium alloys
require special treatment with regard to the mechanical properties of the material in case of temperature increase. In principle, the following is to be observed:
B 11 - 5
a) The insulation of "A" or "B" Class divisions shall be such that the temperature of the structural core does not rise more than 200 °C above the ambient temperature at any time during the relevant exposure to the standard fire test.
b) Special attention shall be given to the
insulation of aluminium alloy components of columns, stanchions and other structural members required to support helidecks as well as lifeboat and liferaft stowage, launching and embarkation areas, and "A" and "B" Class divisions to ensure that
– for such members supporting helidecks,
lifeboat and liferaft areas and "A" Class divisions, the temperature rise limitation specified in a) above applies at the end of one hour; and
– for such members required to support "B" Class divisions, the temperature rise limitation specified in a) above applies at the end of half an hour.
2.3 Crowns and casings of machinery spaces of category A shall be of steel construction adequately insulated, and openings therein, if any, shall be suita- bly arranged and protected to prevent the spread of fire.
3. Terms and definitions
For basic definitions in connection with structural fire protection, such as
– "non-combustible material", – "standard fire test",
– "A Class division", "B Class division", – fire zone(s), etc.,
reference is made to the rules and regulations mentioned under 1.1 and 1.2 above.
4. Structural fire protection requirements
4.1 Definitions of spaces
4.1.1 Control stations are those spaces in which the unit's radio or main navigating equipment is located, or where the production control is centralized, or where the fire recording or fire control equipment or the dynamical positioning control system is cen- tralized, or where a fire extinguishing system serving various locations or a central ballast control station is situated. In the application of this section, the space where the emergency source of power is located is not considered as being a control station.
4.1.2 Corridors means corridors and lobbies.
4.1.3 Accommodation spaces are those used as public spaces, cabins, offices, hospitals, cinemas, games and hobbies rooms and similar spaces. Public spaces are those portions of the accommodation which are used for halls, dining rooms, lounges, and similar permanently enclosed spaces.
4.1.4 Stairways are interior stairways, lifts and escalators (other than those wholly contained within the machinery spaces) and enclosures thereto.
In this connection a stairway, which is enclosed only at one level, should be regarded as part of the space from which it is not separated by a fire door.
4.1.5 Service spaces (low risk) are lockers, store rooms and working spaces, in which no flammable materials are stored, drying rooms and laundries. 4.1.6 Machinery spaces of Category A are all spaces which contain
– internal combustion type machinery used
either for main propulsion or other purposes, where such machinery has in the aggregate a total power of not less than 375 kW;
– any oil-fired boiler or oil fuel units; – trunks to such spaces.
4.1.7 Other machinery spaces are all machinery spaces except those of Category A containing propelling machinery, boilers and other fired process equipment, oil fuel units, steam and internal combustion engines, generators and major electrical machinery, oil filling stations, refrigerating, stabilizing, ventilation and air-conditioning machinery and similar spaces, and trunks to such spaces.
4.1.8 Hazardous Areas are all those areas where, due to the possible presence of a flammable atmosphere arising from the production operations, the use without proper consideration of machinery or electrical equipment may lead to increased fire or explosion hazard. See also A. above.
4.1.9 Service spaces (high risk) are lockers, store rooms and working spaces in which flammable materials are stored, galleys, pantries containing cooking appliances, paint rooms and workshops other than those forming part of the machinery space. 4.1.10 Open decks are open deck spaces, excluding Hazardous Areas.
4.1.11 Sanitary and similar spaces are communal facilities such as showers, baths, lavatories etc., and isolated pantries containing no cooking appliances. Sanitary facilities which serve a space and with access only from that space shall be considered a portion of the space in which they are located.
4.1.12 Crude oil pump room is a space containing crude oil conveying pumps, and includes entrances and trunks leading to such a space.
4.2 Fire integrity of bulkheads, decks and superstructure boundaries
4.2.1 In addition to complying with the specific Provisions for fire integrity of bulkheads and decks in the detailed regulations mentioned under 1.2, the minimum fire integrity of bulkheads and decks should be as shown in Tables 11.1 and 11.2.
4.2.2 Application of the tables
4.2.2.1 Tables 11.1 and 11.2 apply respectively to the bulkheads and decks separating adjacent spaces as defined under 4.1.
4.2.2.2 For determining the appropriate fire integrity standards to be applied to divisions between adjacent spaces, such spaces are classified according to their fire risk: Categories 1 to 12, corresponding to the definitions given in 4.1. The title of each category is intended to be typical rather than restrictive.
Table 11.1 Fire integrity of bulkheads separating adjacent spaces
Section 11 - Fire Safety B 11 - 7
Table 11.2 Fire integrity of decks separating adjacent spaces
4.2.3 Perforations: Where "A" Class divisions are pierced for the passage of electric cables, pipes, trunks, ducts, etc., or for girders, beams or other structural elements, arrangements shall be made to ensure that the fire resistance is not impaired.
4.2.4 Exterior boundaries of superstructures and deckhouses enclosing accommodation, including any overhanging decks which support such accommodation, should be constructed to "A-60" standard for the whole of the portion which faces the crude oil storage area (and/or the production area, if this, in exceptional cases, is arranged nearby - see A.1.2 above). On the side and top portions the same applies to the boundary plating for a distance of not less than 3 m from the portions mentioned above. BKI may accept equivalent arrangements.
4.3 Arrangement and type of openings
4.3.1 The BKI rules mentioned under 1.2 above are applicable regarding details, depending on the type of unit. Some important principles are stated below. 4.3.2 Doors
4.3.2.1 External doors in superstructures and deckhouses should be constructed to "A-0" Class division and be self-closing, where practicable. 4.3.2.2 No doors shall be arranged in or near superstructure boundaries facing the crude oil storage and production areas, if they would provide access to accommodation and service spaces, or to control stations. Doors leading to other spaces, not having direct connection to spaces as listed above, may be permitted, provided that the boundaries of the spaces are insulated to "A-60" standard.
4.3.2.3 The construction of all doors and frames in Class divisions, including the means of securing them when closed, shall provide resistance to fire as well as to the passage of smoke and flames, as far as practicable, equivalent to that of the bulkheads in which the doors are situated. Such doors and door frames shall be constructed of steel or other equivalent material.
4.3.2.4 Doors in "A" Class divisions must be capable of being opened and closed from each side of the bulkhead by one person only.
4.3.3 Windows, sidescuttles, skylights
4.3.3.1 Windows and sidescuttles, with the exception of navigating bridge windows, should be of the non- opening type. Navigating bridge windows may be of the opening type, provided the design of such windows would permit rapid closure. Windows and sidescuttles outside Hazardous Areas may be of the opening type, depending on the applicable Admini- stration regulations.
4.3.3.2 Skylights for crude oil pump rooms shall be of steel (without glass panes) and shall be capable of being closed from outside the pump room.
4.4 Corridors
Corridor bulkheads, including doors, should be "A" or "B" Class divisions extending from deck to deck. Where continuous "B" Class ceilings and/or linings are fitted on both sides of the bulkhead, the bulkhead may terminate at the continuous ceiling or lining. Doors of cabins and public spaces in such bulkheads may have a louvre in the lower half. Such openings should not be provided in a door in an "A" or "B" Class division forming a stairway enclosure.
For escape ways, see Section 10, A. 4.5 Stairways, elevator trunks
4.5.1 Stairs shall be constructed of steel or equiva- lent material. Stairways which penetrate only a single deck shall be protected at least at one level by "A" or "B" Class divisions and self-closing doors so as to limit the rapid spread of fire from one deck to an- other.
4.5.2 Personnel lift trunks should be protected by "A" Class divisions.
4.5.3 Stairways and lift shafts which penetrate more than a single deck should be surrounded by "A" Class divisions and protected by self-closing doors at all levels. Self-closing doors should not be fitted with hold-back hooks. However, hold-back arrangements incorporating remote release fittings of the fail-safe type may be utilized.
4.6 Ventilation ducts
4.6.1 Ducts provided for ventilation of machinery spaces of Category A and Hazardous Areas shall not pass through accommodation and service spaces or control stations. However, relaxation from this requirement may be permitted provided that
– the ducts are constructed of steel and
insulated to "A-60" standard; or
– the ducts are constructed of steel and fitted with an automatic fire damper close to the boundary penetrated, and insulated to "A-60" standard from the machinery space of Category A to a point at least 5 m beyond the fire damper.
4.6.2 Ducts provided for ventilation of
accommodation and service spaces or control stations should not pass through machinery spaces of Category A or Hazardous Areas. However, relaxation from this requirement may be permitted provided tile ducts are constructed of steel and an automatic fire damper is fitted close to the boundaries penetrated.
4.7 Fire protection of helidecks: See Section 9, 4. 5. Fire and blast walls
5.1 Where, on open decks, a satisfying
separation of areas corresponding to different hazard classification or different fire zones cannot be achieved, or where an improved protection of important escape ways is considered necessary, the arrangement of fire or blast walls may be required. 5.2 A fire wall shall in principle be constructed to A-60 standard. The structure shall be adequate to withstand the environment forces and the inclinations/accelerations to be expected at the particular location on the unit.
Where the wall is supported by other structures, such as a superstructure or deckhouse, also the connecting elements shall be suitably protected against fire. 5.3 For the design and construction of blast walls, the particular situation (geometrical configuration, nature of explosion source, etc.) shall be evaluated, considering, i.e.,
– the "worst case scenario" regarding energy dissipation/occurring pressures, and
– the kind of installations and structures to be protected.
C. Control Stations, Fire and Gas Detection