Introduction to Fire Safety Management

stairs
3
Actual Travel Distance
Direct Travel Distance
Figure 9.30 Actual and direct travel distances
the occupants of the inner room are aware of conditions
in the access room. Commonly this is achieved by
providing glazing in the wall and door separating the two
rooms, or providing automatic fi re detection in the access
room. It may also be necessary to restrict the use of the
access room to reduce the risk of outbreak from fi re,
which would prevent the escape from the inner room.
For example, egress from an inner room should not be
through a high risk area such as a kitchen or workshop.
Stage 2 Travel – from the compartment of origin to
a place of relative safety
The next stage of the escape process is from the compartment
where the fi re ignited. This is usually via a circulation
route leading to:
➤ A fi nal exit
➤ A protected stairway or
➤ An adjacent compartment that provides a refuge.
stairs
The occupants need to reach a place of safety, either by
leaving the building completely or by being isolated from
the fi re by effective fi re containment measures and fi re
resisting construction.
The building should be designed so that any compartmentation
affords the occupants suffi cient time to escape
from the compartment of origin before being overcome by
fi re and smoke. However, it is diffi cult to calculate precise
times because people, buildings and fi res vary, and most
codes and legislation specify distances based on experience
of past fi res and past experiences.
Fire protection in buildings
*
Figure 9.31 Extended travel distance due to fi xed chairs,
tables, etc.
A designer therefore must work from fi rst principles
and make an assessment of the life risk and feasible
travel distances.
Table 9.6 gives some typical values for travel
distances that can be applied at a preliminary design
stage, or where there is no controlling legislation or
guidance.
The travel distances must be calculated to take
account of the internal layout for furniture and fi ttings.
Special risks associated with very tall buildings (i.e.
over 10 storeys) or deep basements (i.e. more than one
level) require special attention.
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