(IV-7-3) General Safety

Rules IV Industrial Services
Part 7 Offshore Substations
Chapter 3 General Safety
Section 7
Passive Fire Protection
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. Doors in "A" class
divisions must be capable of being opened and closed from each side of the bulkhead by one person
only.
A.5.2 Intersections and penetrations
In approving fire protection details, GL will have regard to the risk of heat transmission at intersections
and thermal points of required thermal barriers.
Where "A" class divisions are pierced for the passage of electric cables, pipes, trunks, ducts, etc., or for
girders, beams or other structures, arrangements shall be made to ensure that the fire resistance is not
impaired. Penetrations to be of approved type.
If a space is divided with a deck or bulkhead of “A” class standard having insulation of different values,
the insulation with the higher value should continue on the deck or bulkhead with the insulation of the
lesser value for a distance of at least 450 mm.
A.5.3 Windows
GL permits windows outside hazardous areas to be of opening type.
A.5.4 Corridors
All bulkheads required to be "B" class divisions shall extend from deck to deck and to the deckhouse side
or other boundaries, unless continuous "B" class ceilings or linings are fitted on both sides of the bulkhead,
in which case the bulkhead may terminate at the continuous ceiling or lining.
In corridor bulkheads, ventilation openings may be permitted only in and under the doors of cabins, public
spaces, offices and sanitary spaces. The openings shall be provided only in the lower half of the door.
Where such an opening is in or under a door, the total net area of any such opening or openings shall not
exceed 0.05 m 2 . When such an opening is cut in a door it shall be fitted with a grille made of noncombustible
material. Such openings shall not be provided in a door in a division forming a stairway closure.
A.5.5 Stairs
Stairs shall be constructed of steel or equivalent material.
A.5.6 Stairways and lifts
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 another.
Stairways and lift shafts which penetrate more than a single deck shall be surrounded by "A" class divisions
and protected by self-closing doors at all levels.
Self-closing doors shall not be fitted with hold-back hooks. However, hold-back arrangements incorporating
remote release fittings of the fail-safe type may be utilized.
Personnel lift trunks shall be protected by "A" class divisions.
A.5.7 Air spaces
Air spaces enclosed behind ceilings, paneling’s or linings shall be divided horizontally by close fitting
draught stops spaced not more than 14 meters apart.
In the vertical direction, such enclosed air spaces, including behind linings of stairways, trunks, etc.
should be closed at each deck.
A.5.8 Insulation
Except for insulation in refrigerated compartments, insulation material, pipe and vent duct lagging, ceilings,
linings and bulkheads shall be of non-combustible material. Insulation of pipe fittings for cold ser-
Edition 2013 Germanischer Lloyd Page 7–5