NEW
YORK—The U.S. Commerce Department’s National
Institute of Standards and Technology (NIST) today called
on the organizations that develop building and fire
safety codes, standards and practices—and the
state and local agencies that adopt them—to make
specific changes to improve the safety of tall buildings,
their occupants and first responders. The recommendations
result from the agency’s investigation of the
fires and collapses of New York City’s World Trade
Center (WTC) towers following the terrorist attacks
of Sept. 11, 2001.
Based
on the findings of the most detailed examination of a building
failure ever conducted, NIST is making 30 recommendations.
“We believe these recommendations are both realistic
and achievable within a reasonable period of time, and should
greatly improve the way people design, construct, maintain
and use buildings, especially high-rises,” said WTC
Lead Investigator Shyam Sunder at a press briefing in New
York City. “The recommendations also should lead to
safer and more effective building evacuations and emergency
responses. However, improvements will only be realized if
they are acted upon by the appropriate organizations.”
The recommendations, contained within 43 draft reports (totaling
some 10,000 pages) released today for a six-week public comment
period, cover:
- specific
improvements to building standards, codes and practices;
- changes
to, or the establishment of, evacuation and emergency response
procedures; and
- research
and other appropriate actions needed to help prevent future
building failures.
The recommendations
(see the NIST WTC Web site at http://wtc.nist.gov
for the complete list) are divided into eight groups:
- Increased
Structural Integrity: The standards for estimating the
load effects of potential hazards (e.g., progressive collapse,
wind) and the design of structural systems to mitigate the
effects of those hazards should be improved to enhance structural
integrity.
Among the recommendations in this group are:
- nationwide
adoption of standards and codes to prevent progressive
collapse;
- more
reliable means of predicting failure in structures subjected
to multiple hazards; and
- nationally
accepted standards for wind tunnel testing of prototype
structures and estimating wind loads for tall buildings.
- Enhanced
Fire Resistance of Structures: The procedures and practices
used to ensure the fire resistance of structures should
be enhanced by improving the technical basis for construction
classifications and fire resistance ratings; improving the
technical basis for standard fire resistance testing methods;
using the “structural frame” approach to fire
resistance ratings; and developing in-service performance
requirements and conformance criteria for spray-applied
fire resistive materials (SFRMs, commonly referred to as
“fireproofing” or “insulation”).
Among the recommendations in this group are:
- evaluating,
and where needed, improving the technical basis for
determining appropriate construction classifications
and fire rating requirements—especially for buildings
greater than 20 stories in height—and making related
code changes now by considering a variety of factors
(including timely access by emergency responders, full
evacuation of occupants and redundancy in fire protection
systems critical to structural safety);
- improving
the century-old standard for fire resistance testing
of building components, assemblies and systems; and
- developing
and implementing criteria, test methods and standards
for measuring the in-service performance and as-installed
condition of “fireproofing.”
- New
Methods for Fire Resistance Design of Structures: The
procedures and practices used in the design of structures
for fire resistance should be enhanced by requiring an objective
that uncontrolled fires result in burnout without local
or global collapse. Performance-based methods are an alternative
to prescriptive design methods. This effort should include:
(1) the development and evaluation of new fire resistive
coating materials and technologies, and (2) the evaluation
of the fire performance of conventional and high-performance
structural materials (such as fire-resistant steels and
concretes). Technical and standards barriers to the introduction
of new materials and technologies should be eliminated.
- Active
Fire Protection: Active fire protection systems (i.e.,
sprinklers, standpipes/hoses, fire alarms and smoke management
systems) should be enhanced through improvements to design,
performance, reliability and redundancy of such systems.
Among the recommendations in this group are:
- enhanced
fire protection systems that provide redundancy and
accommodate greater risks associated with increasing
building height and population, more open spaces and
higher threat profiles of particular buildings;
- fire
alarms and communications systems that provide continuous,
reliable and accurate information on life safety conditions;
and
- real-time
secure transmission of data from fire alarm and other
monitored building systems for use by emergency responders
at any location, and presentation of that information
either off-site or in a black box that that can survive
a fire or other building failure.
- Improved
Building Evacuation: The process of evacuating a building
should be improved to include system designs that facilitate
safe and rapid egress; methods for ensuring clear and timely
emergency communications to occupants; better occupant preparedness
for evacuation during emergencies; and incorporation of
appropriate egress technologies.
Among the recommendations in this group are:
- improving
occupant preparedness for building evacuations through
joint and nationwide public educational campaigns;
- designing
tall buildings to accommodate full building evacuation
of occupants if needed—including stairwell and
exit capacity that accommodates counterflow due to access
by emergency responders;
- maximizing
the remoteness of egress components (i.e. stairs, elevators)
without making them hard to reach;
- using
pagers and cell phones for broadcast warning systems
and Community Emergency Alert Networks; and
- evaluating
for future use such advanced evacuation technologies
as protected/hardened elevators, exterior escape systems
and stairwell navigation devices.
- Improved
Emergency Response: Technologies and procedures for
emergency response should be improved to enable better access
to buildings, response operations, emergency communications,
and command and control in large-scale emergencies.
Among the recommendations in this group are:
- installing
fire-protected and structurally hardened elevators to
improve emergency response activities in tall buildings;
- installing,
inspecting and testing emergency communications systems
to ensure that the systems and their protocols will
function in challenging radio frequency propagation
environments and can be used to track emergency responders
within a building; and
- developing
and implementing protocols for ensuring effective and
uninterrupted operation of the command and control system
in large-scale building emergencies.
- Improved
Procedures and Practices:
The procedures and practices used in the design, construction,
maintenance, and operation of buildings should be improved
to include encouraging code compliance by nongovernmental
and quasi-governmental entities; adoption and application
of egress and sprinkler requirements in codes for existing
buildings; and retention and availability of building documents
over the life of a building.
- Education
and Training: The professional skills of building and
fire safety professionals should be upgraded through a national
education and training effort for fire protection engineers,
structural engineers and architects.
NIST
strongly urges that immediate and serious consideration be
given to these recommendations by the building and fire safety
communities—especially designers, owners, developers,
codes and standards development organizations, regulators,
fire safety professionals, and emergency responders. NIST
also strongly urges building owners and public officials to
(1) evaluate the safety implications of these recommendations
to their existing inventory of buildings; and (2) take the
steps necessary to mitigate any unwarranted risks without
waiting for changes to occur in codes, standards and practices.
NIST further urges state and local agencies to rigorously
enforce building codes and standards since such enforcement
is critical to ensure the expected level of safety.
NIST
is assigning top priority to work vigorously with these communities
to ensure that there is a complete understanding of the recommendations
and their technical basis and to provide needed technical
assistance for their implementation. As part of this effort,
NIST will develop and maintain a web-based system with information
on the status of NIST’s recommendations that will be
available to the public so that progress in implementing them
can be tracked.
In addition,
NIST will hold a conference on Sept. 13–15, 2005, at
its headquarters in Gaithersburg, Md., to reinforce the importance
of its findings and recommendations from the investigation
and encourage their implementation. Details on this conference
and registration information are available at http://wtc.nist.gov.
NIST
welcomes comments on the draft reports and recommendations—available
online at http://wtc.nist.gov—which
are received by 5 p.m. Eastern Daylight Time on Aug. 4, 2005.
Comments (instructions for submission are available at on
the Web page above) may be submitted via:
- a
link on the WTC Investigation Web site, http://wtc.nist.gov;
- e-mail
to wtc@nist.gov;
- fax
to (301) 975-6122; or
- surface
mail to WTC Technical Information Repository, Attn: Mr.
Stephen Cauffman, NIST, 100 Bureau Dr., Stop 8610, Gaithersburg,
Md. 20899-8610.
NIST’s
investigation of the WTC towers fires and collapses was conducted
under the National Construction Safety Team (NCST) Act. The
act gives NIST the responsibility for conducting fact-finding
investigations of building-related failures that result in
substantial loss of life. NIST has no regulatory authority
under the NCST Act.
The
NCST Act also states that no part of any report resulting
from a NIST investigation into a structural failure or from
an investigation under the Act may be used in any suit or
action for damages arising out of any matter mentioned in
the report.
As an
agency of the U.S. Department of Commerce’s Technology
Administration, NIST develops and promotes measurement, standards
and technology to enhance productivity, facilitate trade and
improve the quality of life.
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