International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 2
Number 2
June 2008
187
Analysis of Factors Affecting the Evacuation of
People from Vessels in Life-Endangering
Situations
D. Lozowicka
Maritime University of Szczecin, Szczecin, Poland
ABSTRACT: The trends to build ever larger passenger vessels enforce the necessity of continuous
improvement of safety systems on such ships. Sea voyages constitute nowadays an attractive form of spending
one’s leisure, which is why people aboard vessels should also have their safety ensured in the case of a
necessity to evacuate them. Paper presents the methods of lengthening of the time available for conducting
evacuation, shortening the time of becoming aware of the necessity of evacuation and shortening the time of
evacuation itself. An interesting concept of signalling the direction of evacuation by means of sound, bound
strictly with the way man’s instrument of hearing functions and the way of locating the source of sound is also
presented at the paper. A new approach to designing evacuation systems is discussed at the paper. The concept
of a “safe haven” is presented.
1 INTRODUCTION
The trends to build ever larger passenger vessels
enforce the necessity of continuous improvement of
safety systems on such ships. Sea voyages constitute
nowadays an attractive form of spending one’s
leisure, which is why people aboard vessels should
also have their safety ensured in the case of a
necessity to evacuate them. The analysis of factors
affecting the evacuation process should take place
already at the stage of designing the vessel, which
permits the partial elimination of hazards during the
vessel’s operation.
The time of potential evacuation of the people
should not exceed the time available for its conduct.
It should be remembered that the time at our disposal
is reduced by the time necessary for becoming aware
of the need for evacuation (Fig. 1).
For buildings on land the real evacuation time is
counted up to the moment of leaving the building.
For vessels, this process has to be divided into the
following stages: relocation from the place of being
alerted to the assembly place, abandoning the vessel
(boarding the life-saving means and their launching
on water, or lowering the life-saving means and
skating).
Estimating evacuation time can be performed by
various methods; the most convenient and currently
ever wider applied form is computer simulation of
the evacuation process.
Fig. 1. Diagrammatic image of the dependence between real
time of evacuation and the time available for its conduct
188
2 MEANS OF ENSURING SAFETY DURING
A SEA VOYAGE
In order to create a system permitting to avoid the
necessity of evacuation, it would be necessary to
eliminate human errors leading to the emergence of
life-threatening situations at the stage of designing,
constructing and operating the vessel. Yet this is not
always possible, which is evidenced by occasionally
happening sea disasters, sometimes causing
fatalities. Therefore, efforts should be concentrated
on a possibly safe evacuation from the vessel, seeing
that situations threatening human life at sea, cannot
be totally eliminated (Fig. 2).
safety of passengers
designing,
constructing,
operation
stage
avoiding emergency situation
YES
NO
lengthening the time
available for evacuation
shortening of time of
becoming aware of
need of evacuation
shortening
evacuation time
Systems of
dete
ction and
alarm signaling
Geometry of surroundings
System
protecting
against
life-
threatening
situations
H
uman factor
Marking of evacuation routes
Eliminating human
error:
Fig. 2. Diagram presenting means of ensuring safety during a
vessel voyage
In the case when it is impossible to avoid a
situation enforcing evacuation (eg. fire, collision), it
should be attempted to lengthen the time available
for evacuation, to shorten evacuation time, and also
to shorten the time of becoming aware of the
necessity of abandoning the vessel.
Lengthening of the time available for conducting
evacuation can be attained by improving security
systems before crossing the life-threatening
conditions. First of all, one should bear in mind the
difficult conditions for movement and the vessel’s
list. The presence of fire affects man through smoke,
thermal radiation, or shortage of oxygen. These
factors endanger man’s safety, and may make
evacuation difficult or downright impossible, and
constitute direct threat to human health and life.
Particular attention should be paid to the application
of appropriate equipment materials. In staircases and
corridors it is necessary to make shorings and
insulations from non-flammable materials.
Uncovered surfaces in staircases and corridors
should be made of materials which spread flames
slowly (SOLAS). When putting finishing touches to
interiors, particularly in corridors and staircases, they
should be selected in such a way that they do not
emit excessive amounts of toxic gases and smoke.
Shortening the time of becoming aware of the
necessity of evacuation is significantly affected by
the human factor. The randomness of population
among the passengers should be taken into
consideration (eg. the appearance of drunks) and
concentrate first of all on improving the systems of
detection and alarm signalling. Early detection of
menace and starting evacuation gives better chances
of conducting it in the time at our disposal, up to the
moment when conditions on the vessel exceed the
values safe for human health and life.
Shortening the time of evacuation itself is
affected, among other things, by the geometry of
evacuation routes and their appropriate marking
(Łozowicka, 2006). Proper information plays an
essential role in conditions of threat, enabling man to
make the right decision concerning the direction of
evacuation. In a labyrinth of routes, frequently in
conditions of restricted visibility, man faces the
necessity of choosing the direction of further route at
each encountered bifurcation. The decision is made
in a state of strong nervousness caused by the
existing menace. Man finds himself in a situation
unusual for him and even a simple layout of
corridors does not warrant his avoiding straying and
wandering around the same paths. An appropriate
combination of lighting and evacuation marking
permits a fast and safe evacuation of people from the
place of threat.
An interesting concept is the suggestion of
signalling the direction of evacuation by means of
sound, bound strictly with the way man’s instrument
of hearing functions and the way of locating the
source of sound. Man’s instrument of hearing is
essentially a mechanical system very sensitive to
small changes in the surrounding sound waves. A
sound wave emitted from a certain source first
reaches the ear situated closer. On the basis of
various pressures in each of the ear channels, man is
able to locate the source of sound (O’Connor, 2005).
During experimental evacuation of ferries
(Withington, 2001) evacuation time was in many
cases shortened by 30%.
The individual course of evacuation is also
affected by knowledge of the layout of corridors, sex
and age of participants of the evacuation, as well as
their physical condition. The efficiency of
evacuation is also strongly influenced by people’s
extra-evacuation activities, like awaiting further
information, fire-fighting, alerting others, awaiting
189
help, attempts at rescuing belongings etc.
(Łozowicka, 2003).
3 A NEW APPROACH TO DESIGNING
EVACUATION SYSTEMS
Work aimed at improving the safety of life at sea has
been conducted by International Maritime
Organisation experts for many years. In future it is
planned to depart from the necessity of evacuating
passengers from a vessel in the case of the
emergence of a crisis situation. The concept of a
“safe haven” is arising, according to which it is just
the vessel herself that is to constitute the best
“lifeboat”. In the case of emergency the vessel
should reach the port using her own propulsion. It is
assumed that passengers and crew will get evacuated
to safe regions on board the vessel, where they will
have adequate conditions for survival (not
necessarily luxurious ones) until the vessel makes
the port (IMO, 2004). For the designers of modern
passenger vessels this means in practice the striving
to fulfil the following requirements:
1 Attaining of a vessel’s suitable resistance to
damage.
2 Retaining a proper operational level by the vessel
in the case of emergency.
3 Ensuring safe conditions for people’s health and
life in the case of emergency.
In the case of emergency it is assumed for people
to stay on board for a few hours; this is to be
prolonged in future to a few days, which is
connected with the necessity of providing people
with living standards (food, toilets etc.). As long
as dangers attendant on sea voyages cannot be
eliminated, however, and until the time of
implementing the “safe haven” concept, efforts
should be made to minimise casualties among
people in case of emergency, by ensuring for them
safe and efficient evacuation from the vessel.
4 RESUMÉ
Disasters at sea happening for years and human
casualties connected with them, have enforced
the necessity of performing evacuation analyses
and designing safe evacuation systems. Methods
of constructing, equipping and
marking evacuation
routes are continuously improved. Even at the stage
of designing the vessel numerous models arise,
which simulate the evacuation process. An important
role is played by methods of informing passengers
and securing evacuation routes. The application of
the smallest number of simplifications and taking
into account of the largest number of parameters
affecting the evacuation process will permit
predicting its course in the case of real menace and
may minimise the number of fatalities in future.
Perfecting methods of analysing evacuation time is
indispensable to ensure the passengers of safety
during sea voyages, the more so, since they have
been becoming in recent times not only a means of
moving, but they are also a way of spending one’s
leisure in an attractive way.
REFERENCES
International Convention for Safety of Life at Sea. 1986,
Consolidated text of the 1974 SOLAS Convention, the 1978
SOLAS Protocol, the 1981 and 1983 SOLAS Amendments.
IMO, London.
International Maritime Organisation (IMO), 2002, Interim
Guidelines for evacuation analysis for new and existing
passenger ships, MSC Circular n. MSC/Circ.1033, 26-th
June.
International Maritime Organisation (IMO) January 2004,
Large passenger ship safety, document FP 48/WP.7/ Rev 1,
London.
Łozowicka, D. & Krystosik, A. & Krystosik, P. 2003, Human
factor in case the fire growth at the ship. KONBIN ’03,
Akademia Morska, Gdynia.
Łozowicka, D. & Łozowicki, A. 2006, Konstrukcja dróg
ewakuacji na statku pasażerskim w aspekcie zapewnienia
bezpieczeństwa życia na morzu. Zeszyty Naukowe
Akademii Morskiej w Szczecinie, nr (11)83, EXPLO-SHIP
2006, Szczecin.
O’Connor, D.J. 2005, Directional sound, NFPA Journal,
May/June.
Withington, D. 2001, Directional sound for emergency
evacuation.. Paper prepared for Forty Fifth Session of the
IMO Sub Committee on Fire Protection, January.
