Civil Engineering Reference
In-Depth Information
assistance to use the means of escape provided for the
able bodied.
Figure 10.8 includes individuals who may be affected
by disabilities that are not readily apparent to the onlooker,
for example some psychological disorders or phobias can
affect an individual's ability to effectively use the means
of escape which are provided for general use. Although
most people within this group may be perfectly capable
of using, for example, an external staircase, they should
ideally evacuate following, not among, other evacuees.
The empirical evidence suggests that less than 1%
of the generally active population, outside institutions,
use movement aids such as wheelchairs, walking frames,
crutches, etc., and some of this group are able to use
stairs unassisted, but at a reduced speed.
With the introduction (as a result of the DDA) of
the duties placed on persons who control access to
buildings to provide access for those with disabilities, the
numbers of people using movement aids in workplaces
may be expected to increase.
In many fatal fi res it is a fact the people are not fully
conscious for a number of reasons, including:
➤
Being asleep
➤
Being under the infl uence of alcohol or recreational
drugs
➤
Suffering from a condition that results in confusion
➤
Being under the infl uence of medication.
Where it is known or can be reasonably foreseen that
persons requiring to escape a building in case of fi re
may have a reduced state of consciousness, considera-
tion must be given to increasing the standard of means
of escape, including the provision of adequate detection
and warning systems that ensure early warning is given
to occupants.
Staff evacuation procedures must also be taken into
account, especially when dealing with occupancies such
as residential care premises, where total evacuation may
be inappropriate.
Initial reaction
Research has shown that the average time to react to
the alarm (i.e. start to move) is normally approximately
30 seconds. However, there are occasions where the
time taken to initially react to a fi re or alarm has been
greatly extended, for example:
State of consciousness
An important aspect that affects individual survival from
a fi re situation is the time delay between discovery of a
fi re and people beginning to evacuate. In the best cases
persons who need to evacuate a building will be awake
and alert at the time they are required to react to a fi re or
an alarm.
➤
In hotels where people may be asleep
➤
In offi ces where people may be engaged with fi nish-
ing a particular piece of work
➤
In sports halls where people may be changing or
engaged in a sporting activity
Enquiries into disasters such as the Summerland fi re
and the Bradford City Football Club fi re indicate that
Figure 10.9
Alcohol affects people's reaction to
emergencies
Figure 10.8
Evacuation chair in use
