
EVACUEE PRE-MOVEMENT TIMES EXTRACTED FROM TWO UNANNOUNCED FIRE DRILLS
FROM EDUCATION AND HOSPITAL FACILITIES
The subject of this research relates to the generation of data-sets
concerning the pre-movement times of evacuees derived from two unannounced
fire drills. This research relates to evacuation analysis and the use of
evacuation modelling tools such as buildingEXODUS.
In evacuation analysis one of the most important factors is the pre-movement
time of the occupants. The pre-movement time (sometimes referred
to as response time) reflects the time spent by the occupant before
starting to evacuate. It includes the time required to perceive the event
and the time required to respond to the event. In many situations
the pre-movement time may be greater than the actual travel time. The pre-movement
time is generally dependent on the nature of the occupancy, the state of
the occupants, the quality of the management system, the type of alarm
system in place, the presence of additional supporting cues (such as the
presence of smoke or instructions from a member of staff) and even the
time of day can be a factor. Typical pre-movement times can vary from seconds
(occupants are awake, trained, familiar with building, alarm systems and
procedures) to many minutes (situations where occupants may require assistance
such as in hospitals). To date, this is arguably one of the poorest
documented attributes in fire safety engineering.
The subject of this research relates to the generation of data-sets
concerning the pre-movement times of evacuees derived from two unannounced
fire drills. In both cases a traditional bell system is used with
the support of trained staff. The structures examined are a listed
university building and a private hospital. The data was generated from
the performance of a fire drill involving the two structures, with researchers
on hand to collect the relevant data.
The first data-set was derived from the evacuation of the Dreadnought
building, - located at the University of Greenwich - which took place on
Thursday 2nd March 2000. A longitudinal analysis was conducted prior to
the evacuation to determine an appropriate and representative time for
the evacuation to take place. The event was an “unannounced fire
drill” of which the students and staff were supposed to be unaware except
for key members of staff.
The university employed a procedure whereby once the alarm sounded nominated
members of staff swept each of the rooms, forcing students to leave their
work and belongings and inform them of the route that they should adopt.
The 'surprise' status of the evacuation was of vital importance to the
usefulness of the data set provided (and of course in testing the performance
of this procedure). The results of the evacuation were recorded on video
tape for later analysis.
The three storey Dreadnought building is part of the Maritime Greenwich
World Heritage Site and since 1999 has been occupied by the University
of Greenwich. The University of Greenwich currently uses the Dreadnought
building for a variety of purposes including providing library services,
housing student computing facilities and a small canteen. A population
of 398 people consisting of both students and staff was recorded evacuating
from the structure. The structure included six staircases and eight exits.
A team of 15 researchers was positioned around the building to record the
data using video and manual observations. Sixty-two closed circuit
cameras were also used to gather data. From the material gathered by the
researchers, a systematic procedure of data extraction was defined allowing
the data to be extracted in a consistent and coherent manner.
The second evacuation drill involved the Blackheath Hospital on the
31st October 2000. The Blackheath Hospital is 69-bed acute care hospital
that serves the private sector (link to two views of the front of
the hospital view1 and view2).
During this time it was not possible to evacuate inpatients (including
the bedridden patients), therefore an evacuation of the outpatients and
staff was observed. Only three members of the senior management were aware
that the evacuation was going to take place and these had no impact on
the outcome of the evacuation. The evacuation was therefore unannounced.
The hospital employed standard procedures whereby once the alarm sounded
members of staff (usually nurses) swept each of the populated areas, informing
patients that they had to leave and the route that they should adopt.
Eight researchers were located around the building, in waiting rooms
and corridors to collect the pre-movement time of the evacuees. This data
was recorded manually or using video equipment. A degree of cross-referencing
between the observations of the researchers was possible to confirm the
results produced. As in the Dreadnought evacuation, there were two classes
of occupant that could easily be distinguished: the staff and the patients.
The two cases have a number of similarities in that to a large degree
the students and patients were dependent upon the actions of the members
of staff to inform them about the situation. Their reaction to the members
of staff and the information provided is reflected in the evacuee’s pre-movement
time.
This research involves categorising the pre-movement times observed
according to the location and role of the evacuee, enabling comparison
within and between the cases.
For more information about evacuation modelling and the EXODUS software
visit the EXODUS Web Pages. For a complete listing of EXODUS and evacuation publications visit
the FSEG Publications pages.
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