| In many cases, a catastrophic fire like the one that
occurred on 11 April 1996 in the Dusseldorf Airport,
provokes the S.A.B.E.N.A. Syndrome : "Such A Bloody
Experience Never Again". It touches building owners
and authorities alike, and the result is a building
concept where any imaginable and available protection
features is included without much consideration for
the necessity and for the economics of such a design.
This apparently happened also in Dusseldorf, as can
be seen in the next review.
The central airport building was completely renewed
and provided for a larger flow of passengers with
more comfort and more services. The new fire safety
concept addresses all weaknesses found during the
analysis of the 1996 event, and uses the following
main goals :
minimising fire loads,
compartimentation
early detection of fire
smoke control
safeguarding the evacuation
Minimising fire loads
Fire loads have been minimised through the use of
non-combustible or difficult to ignite materials for
building insulation, decoration and finishings.
Compartimentation
The new structure was designed to be 1.5h fire resistive
(F90), except for the large hall roof, where fire
simulation calculations indicated that the available
fire load combined with sprinklers could not generate
critically high temperatures. The departure wings
were separated from the main buildings and the lower
floors subdivided in fire compartments. Separations
were made by fire partitions and by fire resistant
glass facades.
Evacuation
Maximum distances to a safe exit way were imposed
and two exit paths were designed for every point of
the building. This results in about 36 protected staircases
which go directly to the open air. External staircases
have smoke vents, internal staircases have overpressure
protection. Additional care was given to indicate
very clearly the exit paths. Doors that have to be
locked for normal security and border control reasons
are linked to the fire detection system so that they
can be unlocked automatically in case of fire.
Fire protection systems
The airport has a very developed alarm and information
management systems, based on a general automatic fire
detection system and a zone-oriented information system
. The fire detection system also controls the air-conditioning,
the smoke management system, the steering of elevators
and the unlocking of emergency exit doors. The system
is subdivided in about 200 fire zones. The communication
system can address people in four languages, and has
numerous features to provide detailed information.
Smoke management
Mechanical smoke management systems have been installed:
the check-in hall is equipped with 26 smoke fans each
of 100.000 Nm3/h capacity. The lower levels have a
special developed smoke management system to,extract
smoke before it can move through opening for light
and communications. Air conditioning is monitored
by the smoke detection to avoid smoke spreading around.
The whole building is now protected by sprinklers,
and special fire protection systems have been foreseen
for special risk areas. The atrium like central hall
has no ceiling sprinklers, which would only operate
with some delay. Instead increased density systems
have been installed below all galeries adjacent to
that area. Low temperature and low RTI were specified
to be sure that a fast response of the sprinklers
can be guaranteed.
FRAME calculation
The data available in the reference article were
enough to recalculate the fire risk for the new concept.
The result shows a very low residual risk, which goes
beyond the standard "good" level proposed
by FRAME. The pendulum swung to the other side as
could be expected: Based on the FRAME calculations,
it is possible to say that in the Dusseldorf Airport,
the fire protection design was not properly balanced:
before the catastrophe it was too poor, afterwards
|
