LESSONS LEARNED
8-Nationally
recognized elevator code requirements for manual
control of elevators during fire emergencies
work.
Elevator control modifications at One Meridian
Plaza were accomplished in accordance with Commonwealth
of Pennsylvania requirements based on ANSI/ASME
A17.1, Safety Code for Elevators and Escalators.
The elevators performed as expected by the standard.
The only problem with the elevator response
was the decision of the building engineer to
override the system to investigate the alarm
9-The ignition source provided by oil-soaked
rags is a lone recognized hazard that continues
to be a problem.
Had the contractor refinishing paneling on
the 22nd floor not carelessly left oil soaked
cleaning rags unattended and unprotected in
a vacant office, this fire would not have occurred.
To pinpoint the particular source of ignition
of this fire as the sole cause of the death
and destruction that followed is a gross oversimplification.
Nevertheless, failure to control this known
hazard is the proximate cause of this disaster.
The danger of spontaneous heating of linseed
oil-soaked rag waste is widely recognized. Each
model fire prevention code requires precautions
to prevent ignition of such materials. At a
minimum, waste awaiting removal from the building
and proper disposal must be stored in metal
containers with tight-fitting, self-closing
lids. Leaving these materials unattended in
a vacant office over a weekend was an invitation
to disaster. This is both an education and an
enforcement problem for fire prevention officials
10-Building security personnel should
be vigilant for fire safety as well as security
threats, especially while construction, demolition.
alteration, or repair activities are underway.
Earlier in the day, the building engineer had
become aware of an unusual odor on the 22nd
floor which he associated with the refinishing
operations which were underway there. When the
alarm system activated later that evening he
first believed the solvent vapors had activated
a smoke detector.
The roving security guard made no mention of
anything unusual during his rounds of the fire
area earlier in the evening. It is conceivable
that no detectable odor of smoke or audible
or visible signals of a fire were present when
the guard last checked the floor. However, a
cursory check is not adequate when construction,
demolition, renovations, or repair activities
are underway in a building area. Fire hazards
are often associated with construction activities,
and buildings are especially vulnerable to fire
during such operations. For these reasons, it
should be standard practice to check these areas
even more carefully and thoroughly than usual.
All building operating and security personnel
should have basic training in fire prevention
and procedures to be followed when a fire occurs.
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11-Emergency electrical systems must be truly
independent or redundant.
Article 700 of the National Electrical Code recognizes
separate feeders as a means of supplying emergency
power. However, Section 700-12(d) requires these services
to be “widely separated electrically and physically...to
prevent the possibility of simultaneous interruption
of supply.” Installing the primary and secondary
electrical risers in a common enclosure led to their
almost simultaneous failure when the fire penetrated
voids in the walls above the ceiling of the 22nd floor
electrical closet. The intense heat melted conductor
insulation resulting in dead shorts to ground which
opened the overcurrent protection on each service
interrupting power throughout the building.
Auxiliary emergency power capability was provided
by a natural gas powered generator located in the
basement mechanical room. This generator was intended
to supply one elevator car in each bank, fire pumps,
emergency lighting and signs, and the fire alarm system.
However, this generator set failed to produce power
when needed. (Generator maintenance records indicated
a history of problems; however, the root cause or
mechanism responsible for these problems was not identified.)
Supplying the generator from the building natural
gas service also left the emergency power system vulnerable
in the event of simultaneous failure of the electrical
and gas public utilities. The transformers that provided
power for the adjacent building were installed in
the basement of the One Meridian Plaza Building. These
transformers had to be shut down due to the accumulation
of water in the basement, resulting in the loss of
power to this building as well. As a result the elevators
in the adjoining building could not be used.
12. The regulations governing fire-resistance
ratings for high-rise structural components should
be re-evaluated.
The degree of structural damage produced during the
fire at One Meridian Plaza suggests that the requirements
for structural fire resistance should be reexamined.
Floor assemblies deflected as much as three feet in
some places. The fire burning on multiple floors may
have produced simultaneous exposure of both sides
of these assemblies, which consisted of concrete slabs
on corrugated decks, supported by structural steel
beam and girder construction, sprayed with cementitious
fireproofing materials. The standard fire test for
floor and ceiling assemblies involves exposure from
a single side only.
Columns and certain other structural elements are
normally exposed to fire from all sides. In this fire,
the steel columns retained their structural integrity
and held their loads. Experience in this and similar
high-rise fires suggest that columns are the least
vulnerable structural members, due to their mass and
relatively short height between restraints (floor
to floor). Major damage has occurred to horizontal
members, without compromising the vertical supports.
13. Features to limit exterior vertical fire
spread must be incorporated in the design of high-rise
buildings.
Exterior vertical fire spread or autoexposure can
be a significant fire protection problem in construction
of high-rise buildings if interior fire growth is
unrestricted. Because of the difficulty with retrofitting
exterior features to restrict fire spread, the installation
of automatic sprinklers to restrict fire growth is
the most simple approach to managing this risk in
existing buildings. Exterior features to prevent fire
spread must usually be designed and built into new
buildings. Many modem (international style) and post-modem
building designs present difficult exterior fire spread
challenges because of their smooth exterior facades
and large glazing areas. Variegated exterior facades
and larger noncombustible spandrels significantly
reduce exterior fire spread effects by increasing
the distance radiant and conductive heat must travel
to stress exterior windows and to heat materials inside
the windows on floors above the fire. |
