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...memories, there is ample reason
to reassess the state of fire safety in newer buildings where
Americans work, live, shop, learn and play," writes Corley.
Schulte and others wonder what
an act of war has to do with fire safety in newer buildingsor
any buildings. The fires, triggered by the attacks, were significantly
larger than fires envisioned by the codes. And the towers'
defenses had been "downed" by terrorists, who used
hijacked planes as missiles.
Schulte also is rankled by empty
rhetoric. During March 6, 2002, congressional hearings on
the disaster, Congressman Sherwood Boehlert (R-N.Y.), said
that with a greater understanding of buildings, it is possible
to "ensure" that "we protect lives in the future"
against terrorists.
"Hold on," others chime
in. Fires ultimately brought down the towers, by sapping strength
from the crippled steel frames. The 47-story Seven WTC, left
on its own to burn, collapsed before burnout. That had never
happened.
Something must be done to prevent
another towering inferno, regardless of the trigger, chorus
experts. There are lessons that can be learned from the performance
of the WTC, especially as relating to skyscraper fire protection
and extreme loads. This is a silver lining to the cloud of
9/11, they say.
Are Schulte and his less vocal
supporters right? Are SSCs charges just? Are those blaming
the fires for the collapse of the towers soothsayers? Is it
acceptable to offer false assurances to calm the public? Is
this a case of the tyranny of the traumatized minority or
are steel high-rises tinderboxes waiting to become towering
infernos, thanks to weak codes and malfeasance on the part
of developers? If there are lessons to be gained, is it ethical
to sound false alarms to learn them?
Statistics offer perspective, say
code experts. According to NFPA, seven civilians died in fires
in 1985-1995 in office towers and 633 in high-rise residential
buildings (589 in apartments). Yet during the same time period,
there were a total of 57,355 civilian deaths in building fires.
Few if any high-rise fire deaths were caused by a collapsed
structure. Most were caused by smoke and heat.
Fire safety in high-rise buildings
is not the problem, says Schulte. "The fire problem"
is with one- and two-family dwellings, he says.
According to Fire Loss in the United
States by Michael J. Karter Jr., 68% of civilian fire deaths
in 1997-2001, excluding those on 9/11, took place in one-
and two-family dwellings. Only 3% occurred in nonresidential
structures.
Martin H. Reiss, president and
CEO in the Framingham, Mass., office of the RJA Group Inc.,
a fire and security consultant, says properly enforced codes
work. "We see it as business as usual from the fire point
of view," he says.
If anything, Reiss fears not enough
attention is being focused on how heightened, post-9/11 building
security clashes with fire safety. Jersey barriers impede
fire trucks and locked doors and security checkpoints impede
egress, he says.
Joseph Caprile, a principal of
Lohan, Caprile Goettsch Architects, Chicago, agrees that model
codes are adequate. He says the problem in some cities is
that adopted codes are antiquated and that many are not retroactive.
Solomon agrees codes work in a
pre-9/11 world. But the burning question is "whether
they work for the newer hazards on everyones radar screen,"
he says.
Still, the fire engineering sector
does not want massive code reform without research, says Solomon.
"Do you change the code for a one in 30-year event or
a one in 50-year event?" he asks. "Prior to 2001,
the answer was no."
Once there is an understanding
of how realistic it is to design for new hazard scenarios,
or hostile acts, the codes will have to be evaluated and probably
modified, says Solomon. Toward that end, NFPA formed a high-rise
advisory committee with members from the public, first responders
and professional groups.
One thing is incontrovertiblethe
tower collapses stoked longstanding feuds and ignited debates.
It remains automatic sprinklers pitted against passive resistance,
concrete versus steel, and there are ongoing concerns with
ASTME119, the materials test for fire ratings.
For designers, it is a question
of the feasibility of designing structures to remain standing
after burnout and the necessity of considering fire as a structural
load (see p. 50). There also is a continuing debate about
performance-based design and the need to address progressive
or "disproportionate" collapse.
Some experts are pushing a multihazard
design approacha method that considers seismic, wind
and fire loads together to achieve the best performance in
extreme events. "Our approach to all hazards needs to
be consistent, which would include a probabilistic and complimentary
approach so that we dont find ourselves overcompensating
for the hazard du jour," says Tom Z. Scarangello,
a managing principal of Thornton-Tomasetti Engineers, New
York City. "If changes are not addressed as part of a
multihazard mitigation-based philosophy, we are missing the
boat," he says.
On the practice side, there is
discussion about the roles of different professionals. Some
fire protection engineers are suggesting a new service to
architects and owners that would combine fire and structural
engineering.
There is still a stairwell-width
debate, issues about retroactive code compliance and a controversy
over using masonry or fire-rated gypsum board for stair enclosures.
Code officials also are considering whether there needs to
be special fire protection and security provisions for landmark
and tall buildings and adjacent properties. Last month, for
example, the International Code Council, a model codewriter,
voted to eliminate allowable reductions in passive containment
for buildings more than 420 ft tall that have sprinklers.
There are less controversial subjects.
Mechanical engineers are weighing the merits of dedicated
elevators for firefighters and using elevators for evacuation.
There also is talk of pressurized stairwells and refuge floors.
NFPA may think more research is
needed to resolve these issues, but Schulte does not. He especially
opposes the $16-million WTCBuilding and Fire Safety Investigation,
concluding this fall, by the National Institute of Standards
and Technology. Schulte is on a mission to expose NIST and
its contractors as having jumped on NISTs post-9/11
gravy train, he says.
"The implementation of the
results of [a WTC] investigation would be critical to restore
public confidence in the safety of tall buildings nationwide
and better protect...
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