“A metallic bulkhead conducts heat very well, and the main
reason for the fitting of structural fire protection is to stop the
spread of fire from one compartment to the next. It is worth remembering
that (aluminium aside) the survival of the structure is not of primary
concern. However, where wood and composites are concerned, the opposite
is true. In this case, the structure is an insulator. The downside of
these materials is that they have relatively poor structural response to
heat. It is for this reason that insulation is required to be fitted to
these structures. So in effect, we are not concerned with spread of fire
through conduction, more with the collapse of the structure. In this
regard, assuming that the structure has been sufficiently protected to
ensure no collapse we are then interested to know what represents a
‘worst case’ thermally for the bulkhead.”