6
Protection time – the structural
fire protection time of main load-bearing structures located within
areas of major fire hazard (classified as A) and areas of moderate
fire hazard (classified as B), and load bearing structures supporting
control stations should, as a minimum, be the same as that required
by tables 7.4-1 and 7.4-2 (as applicable), for the divisions enclosing
the space where these supports are located. In accordance with paragraph
7.4.1.1, in no case should the structural fire protection time be
less than 30 minutes.
7
Insulation – load-bearing
structures made of steel, other than those constituting the divisions
dealt with in tables 7.4-1 and 7.4-2 (as applicable), need not be
insulated.
8
Extent of structural fire protection –
the structures considered should be all load-carrying structures within
areas of major and moderate fire hazard (classified as A or B), as
well as all structures (irrespective of where they are located), which
are necessary to support control stations.
9 The vertical extent of structure supporting
control stations should be considered all the way down to and including
spaces within the hull(s). However, all structures within voids in
the hull can be exempted from this consideration based on paragraph
7.4.2.1 (first part) of the Code.
10
Fire testing – approvals
from the standard fire test according to the 2010 FTP Code, annex
1, part 11, for a bulkhead or
deck of a given material can be applied for protection of pillars
of the same material. The structural fire protection time should be
considered to be the same as that achieved in the fire test.
11
Load case – when load carrying
capability calculations are performed for an assumed fire within a
space, all insulated or uninsulated steel structures, including pillars,
as well as fire insulated aluminium and FRP structures in the space
may be included; uninsulated aluminium and FRP structures should not
be included. A single fire concept can be applied where a fire is
only presumed to originate in one enclosed space and not propagate
to another enclosed space.
Example: Structures within a public space support
a wheelhouse and a separate enclosed public space on the wheelhouse
deck. Two load calculations should then be made:
-
.1 one presuming a fire below the wheelhouse;
utilizing, in the load calculations, uninsulated steel and insulated
aluminium and FRP structures within the public space on the wheelhouse
deck;
-
.2 another presuming fire within the public spaces
on the wheelhouse deck; utilizing, in the load calculations, uninsulated
steel and insulated aluminium and FRP structures within the public
space below the wheelhouse.