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The
National Construction Safety Team Advisory Committee
National
Institute of Standards and Technology
Minutes
of December 2-3, 2003, Meeting - Gaithersburg, Maryland
The
slides from the presentations are embedded as links to
PDF files
within this document and, thus, are summarized in these minutes.
Each presentation was followed by a discussion period. “Q” indicates
a question, “A” the corresponding answer, and “C” a
comment. All questions and comments, unless otherwise noted,
were made by Advisory Committee members. All answers unless
otherwise noted, were by NIST personnel.
The
minutes summarize the main points of each discussion; they
are not intended to be a verbatim transcript
of the meeting.
December
2,
2003
Opening
Remarks
Mr. Paul M. Fitzgerald, Committee Chair
Mr. Paul Fitzgerald opened the National Construction Safety
Team (NSCT) Advisory Committee meeting at 8 a.m. and welcomed
the members of the Advisory Committee, National Institute of
Standards and Technology (NIST) staff, media, and public attendees
to the meeting. Mr. Fitzgerald acknowledged the contribution
of Dr. Jack Snell for his leadership in initiating the two
ongoing investigations and in getting the NCST Advisory Committee
up and running. Dr. Snell retired from NIST in October.
Mr. Fitzgerald reminded the members of the Advisory Committee
and NIST staff that the proceedings of NCST Advisory Committee
meetings will be audiotaped beginning with this meeting. He
encouraged the Advisory Committee members and NIST staff to
identify themselves when speaking and to use the microphones
so that their remarks would be clearly recorded.
Mr. Fitzgerald also reminded the Advisory Committee to phrase
recommendations as a motion for Committee action.
Mr. Fitzgerald then turned the floor over to Dr. Arden L.
Bement, Jr., Director of NIST for his opening remarks.
Dr. Arden L. Bement, Jr., Director, National Institute of
Standards and Technology
Dr. Arden Bement
began by acknowledging Dr. Snell’s
contributions to the ongoing investigations and implementation
of the NCST Act. He noted that Dr. Snell would receive the
Department of Commerce Gold Medal for his leadership in responding
to the World Trade Center (WTC) disaster. Dr. James Hill, Acting
Director of NIST’s Building and Fire Research Laboratory,
will serve as the Designated Federal Officer for the NCST Advisory
Committee.
Dr. Bement stated that NIST has now received all of the essential
information it needs to conduct the WTC Investigation. He also
stated that NIST had reached agreement with the City of New
York to allow NIST access to 9-1-1 records and to transcripts
of 500 first responder interviews. NIST has also received all
of the approvals it needs to conduct first-person data collection,
and the first-person data collection has commenced.
He also noted that a press briefing on The Station Investigation
was held in Providence, Rhode Island, on November 25, 2003,
and that media coverage of the event was extensive.
With regard to implementation of the NCST Act, Dr. Bement
stated that as of November 28, NIST had published all of its
NCST implementing procedures.
Finally, Dr. Bement asked the Committee to review the questions
he had previously provided and requested that the Committee
respond to these questions prior to the next Committee meeting.
WTC
Investigation:
- What
grade do you give the effort on the investigation to date?
Why?
- Where
in your view is it most likely to fall short? Why?
- What
needs to be done to assure that does not happen?· What
must be done to ensure that this a world-class
report?
- Do
you have any advice on how we can assure that
we are doing the
best job possible in managing external communications
including Web sites, media, and public interactions?
NCST
Advisory Committee:·
- Within
the constraints of the role of a Federal
advisory committee, how could we improve our use
of the
committee?
Planning
for the changes needed as
a result of the investigation, R&D
and DTAP:
- Have
we identified all the
right things in the WTC R&D and DTAP
plans? Are there some
things that don’t
belong on the list?
- Are
the right organizations
and interests involved?
- Do
you have any advice
for how we can assure
that
other organizations
are prepared to
quickly consider
and act upon our reports
recommendations?
How could
we improve?
Back to agenda
Status of the World Trade Center Investigation and Discussion
Dr. S. Shyam Sunder, Chief, Materials and Construction Research
Division
PRESENTATION (.pdf;
download Acrobat Reader)
Dr. S. Shyam Sunder
gave an overview of the WTC Investigation stating that the
team was extremely busy and that solid progress
had been made since the last Committee meeting. He acknowledged,
however, that there was still a lot of hard work that needed
to be done and that much of the “heavy lifting” would
occur over the next 4 to 6 months.
Dr. Sunder reported that 15 months into the Investigation
good solid progress has been made. A public update was issued
on December 2, 2003, which provides additional details on the
progress of the investigation (http://wtc.nist.gov). The process
for the selection of external experts and contractors is completed,
and all contracts have been awarded. Four individuals were
hired as expert consultants. Dr. Sunder stated that this is
an excellent group of contractors and experts to augment the
NIST in-house capabilities.
Significant progress has been achieved on data collection
since August 2003. Dr. Sunder pointed out that NIST has received
all of the essential information it needs for the WTC Investigation.
NIST is continuing to seek photographs and videos of the south
face of WTC 7. Also, pursuant to an agreement with New York
City, NIST will be provided access to 911 tapes and logs as
well as transcripts of about 500 first-responder interviews
no later than December 31, 2003.
NIST is reviewing available information related to the calculations
and analyses that supported the original aircraft impact studies
of the WTC towers. Although not normal practice in building
designs, the safety of the towers and their occupants in an
aircraft collision was a consideration in the original design.
Dr. Sunder discussed the different views on the available information.
Dr. Sunder stated that NIST has developed a comprehensive
approach to identify the most probable structural collapse
sequence, from the point of aircraft impact to collapse initiation.
There has been significant progress in defining the requirements
for the complex series of analyses and formulating detailed
technical modeling approaches. Simplified modeling approaches
are also being developed to provide insights and bases to
evaluate results for the detailed models. In addition, NIST
is developing a rigorous technical approach to evaluate the
performance of the fireproofing in the towers and the role
it played in maintaining the integrity of the towers but
not preventing the subsequent collapse.
NIST is continuing to analyze the WTC steel in its possession
and believes the collection of 236 pieces from the WTC towers
is adequate for purposes of its Investigation. Preliminary
results show that the measured room temperature steel strength
met or exceeded relevant ASTM specifications.
Dr. Sunder provided
a brief update on the fireproofing and fire rating of the
WTC floor system. Project-specific fire
endurance testing was not and is not normal practice, but may
be conducted when circumstances warrant it, as for example,
in a new application. NIST has awarded a contract to Underwriters’ Laboratories
to determine the fire rating of typical WTC floor systems under
both as-built and specified conditions.
The collection of photographic and video images continues
to grow. Dr. Sunder stated that from analysis of the images,
NIST has determined the exact times for the major events of
September 11, 2001 (aircraft strike, building collapse initiation).
In addition, NIST has developed detailed mappings for the fire,
smoke, and the condition of windows at several specific times
for each WTC tower.
Dr. Sunder reported that an important milestone was reached
for the project on occupant behavior, evacuation, and emergency
response. NIST received all necessary approvals and has commenced
the first-person data collection efforts. First-person interviews
will provide valuable information to improve public safety
during extreme events in tall buildings. There is currently
a critical lack of information on which to base evacuation
and emergency response practices, standards, and codes in such
conditions.
Part of the WTC Investigation is an analysis of building and
fire codes and practices. Dr. Sunder described the procedures
and practices that are of interest and stated that NIST has
completed a preliminary comparison of then-current building
regulatory and code requirements. In addition, NIST has completed
preliminary documentation of the fuel system for emergency
power in WTC 7.
NIST is investigating the active fire protection systems in
the WTC towers and WTC 7, and Dr. Sunder identified the specific
systems that are being analyzed. These include the sprinkler
system and pre-connected hoses, fire alarm systems, and smoke
management system.
Q: Referring to the list of contract awards, have some contractors
produced final reports? When will the Advisory Committee receive
these reports? Will the Advisory Committee have the opportunity
to review contractor reports?
A: We have not yet received any reports from contractors that
have been approved by NIST. Once they are deemed technically
acceptable, the reports will be at a stage where they can be
shared with the Committee. Some technical reports may be more
appropriate for review by specific experts on the Committee,
while others may be appropriate for the entire Committee. At
what level would the Advisory Committee want to review the
reports?
C: The Advisory Committee should consider procedures for reviewing
reports.
C: (Chair) After the first of the year I will work with Dr.
Hill to set up a procedure for reviewing consultant reports.
C: With regard to ASTM E 119, it is not project specific and
not always used. Projects rarely use E 119.
C: Generally, buildings use assemblages that have had E 119
testing previously done. Testing is not done unless the building
is using systems that have not been tested before. The point
here is that the floor system was sort of never done before,
and the statement here is that maybe it should have been done.
But, normally it is not done.
C: (NIST) E 119 was not or is not routinely conducted. However,
the builder always has the option to conduct the tests, especially
when there are unique aspects involved.
Q: You stated that you have all of the essential information
needed for the Investigation. Can you characterize your understanding
for all three buildings?
A: A lot of information exists for WTC 1 and 2. However, our
feeling is that not a lot of information is kept on older buildings.
After 6 to 8 years, very little information is kept on buildings.
Sufficient information exists for WTC 1 and 2 for NIST to conduct
its investigation. Information for WTC 7 is less complete.
Some information is missing. I feel very good about the amount
of information we have for the towers and reasonably good about
the amount of information for WTC 7.
Back to agenda
Project
1 – Analysis
of Building and Fire Codes and Practices
Dr. H.S. Lew, WTC Investigation, Project 1 Co-Leader
Mr. Richard Bukowski, WTC Investigation, Project 1 Co-Leader
PRESENTATION (.pdf;
download Acrobat Reader)
Dr. H.S. Lew and Mr. Richard Bukowski presented information
on Project 1 of the WTC Investigation, which is an analysis
of building and fire codes and practices.
Dr. Lew described
the building codes used for WTC 1, 2, and 7 and the five
building codes that have been reviewed and compared.
The structural requirements reviewed included dead loads, live
loads, live load reduction, lateral loads (wind and earthquake),
load combination, and progressive collapse resistance. The
review is ongoing, but interim findings indicate that the Port
Authority adopted the 1968 New York City Building Code for
the final design of WTC 1, 2, and 7. It appears that designers
were allowed to use “acceptable engineering practices” with
the approval of the Port Authority where code provisions were
obsolete. Dr. Lew explained additional interim findings regarding
the five codes reviewed.
Mr. Bukowski presented the status on the review of codes for
fire protection and egress systems. He described the building
codes that have been reviewed by NIST and the national fire
safety standards adopted by the 1968 New York City building
codes. The 1968 New York City Code reduced the fire resistance
ratings from the 1938 edition, and the 2001 edition was reduced
further from the 1968 edition. The 1968 New York City Code
contains provisions on topics not covered in other codes. He
explained the New York City Local Laws and their requirements
and applicability.
The fuel system for emergency power in WTC 7 is being analyzed
as part of the investigation. Mr. Bukowski described the systems,
their purpose, and layout.
Q: Mr. Bukowski indicated a difference between the 1967 Chicago
and 1968 New York City fire protection codes. Are there any
other substantial differences between the New York City code
and other codes?
A: Not known as yet, but a side-by-side code comparison is
under way.
Q: Regarding revisions to the New York City code, you indicated
that prior to the 1968 New York City revision, the code was
based on 1938 requirements. These requirements are frequently
amended. Was there an amendment that kicked in before 1968?
A: No. The 4-hour fire resistance for columns and 3-hour fire
resistance provisions stood until the 1968 revision to the
New York City code took effect.
Q: Did you compare NFPA 101 and the building code in effect
at the time?
A: Yes, and they were consistent.
Q: A lot of time has been spent on the fuel system in WTC
7. The 1993 WTC bombing incident report indicated a failure
of the emergency power system for WTC 1 and 2 due to its lower
floor location. Was this an issue during the September 11th
attack?
A: It’s not thought to be an issue. The 1993 explosion
occurred in a garage, and it took out piping for the cooling
water.
Q: In the Federal Emergency Management Agency (FEMA) study,
several floors were reported as mechanical equipment floors.
Were live load reductions different for those floors?
A: Yes, this is common practice. No load reduction was permitted
for these floors.
Q: Excellent and to the point presentation. One of the goals
of the act is to provide recommendations for improvements to
codes, standards, and practices. The Port Authority was not
tied to using the New York City code, but chose to do so. This
is not a problem in major cities, which tend to follow model
codes. In other locations, this is a political decision where
concerns are voiced to minimize requirements to keep down the
cost of buildings so that additional business can be attracted
to a community. The concern is whether recommendations will
be adopted by many jurisdictions. In the earthquake community,
this was addressed by the Interagency Committee on Seismic
Safety in Construction (ICSSC), and Executive Order 12699 on
new construction. This needs to be considered.
A: This is an important issue. The Research & Development
(R&D) and Dissemination and Technical Assistance Program
(DTAP) are intended to address this issue. The suggestion to
consider the ICSSC model will be considered.
Q: Fifty pounds per square foot is generally used for live
loads. What was used in the WTC towers?
A: Generally, higher live loads of 75 to 100 pounds per square
foot were used. Live load requirements for the core area differ
from that of the main floor area.
Back to agenda
Project
2 – Baseline
Structural Performance and Aircraft Impact Damage Analysis
Dr. Fahim Sadek, WTC Investigation, Project 2 Leader
PRESENTATION (.pdf;
download Acrobat Reader)
Dr. Sadek presented information on Project 2 of the WTC Investigation,
which is an analysis of baseline structural performance and
the extent of aircraft impact damage. The project has two primary
objectives. The first is to develop reference structural models
of the WTC towers and establish baseline performance under
design loading conditions (gravity and wind). After completion,
the NIST-approved models will be used as a reference for other
significantly more detailed models to be developed in the investigation
for aircraft impact analysis, thermal-structural response,
and collapse initiation sequence analysis. These detailed models
would be traceable to the reference models. He discussed the
progress on the models, including the structural databases
and the 3-D models of typical floor systems and towers. Final
approval of the reference models is expected shortly.
Dr. Sadek reported that work is also under way on the baseline
performance analysis. The analysis will start upon approval
of the reference models. Progress has been made in defining
wind loading on the towers.
The second objective
of the project is to simulate aircraft impacts on the towers
to estimate probable damage to structural,
mechanical, and architectural systems—including fire
protection systems. Dr. Sadek said this analysis will also
determine how close the buildings were to collapse immediately
after aircraft impact. He presented the status of data collection
on the aircraft structure; aircraft engine model development,
and component level analyses.
C: The work is well thought out. I hope that you get the results
you want. The failure of an exterior column is not affected
by the attachment.
A: Failure at the exterior wall is governed mainly by momentum
transfer and inertia effects due to the high speed of the aircraft.
We will need to run a number of simulations to vary the speed
and failure criteria to determine the failure mode, for example,
by changing the plastic strain to fracture. This will be part
of the sensitivity analysis that will be done.
C: The model will
be looking at failure criteria possibly based on plastic
strain or fracture with or without triaxial
effects. You’ll need to consider ductility with or without
triaxiality.
A: Yes.
C: The experience
over 15 years with wind tunnel testing of high-rise buildings
is that results are more severe today.
A test done today produces higher wind pressures than in the
past and I’m not sure why. We are questioning the wind
tunnel people, but keep this in mind. On another topic, I recall
serious welding problems during construction of the towers
with the column splices. It made Engineering News Record. Someone
should take a look at that.
C: I don’t recall the details. Will that affect the analysis
results? Need to review the data on welding, material properties,
etc., and consider if it is important.
C: My recollection is that it held up the construction.
C: (NIST) We’re
looking at doing component testing and what happens to the
weldment and what happens to the components
in general and comparing it to the simulations we are planning
to do. We definitely need to consider the welding.
Q: (NIST) Are you referring to the bowtie cracks or elsewhere?
A: (Committee Member) Not sure, I only recall that there were
problems with the welding.
C: (NIST) What we know is that there were cracks in the bowties
during construction. The explanation we have been given is
that these were due to freezing and expansion of water and
ice. We saw samples of these bowties with the cracks at JFK
and we have some here at NIST. Our initial hypothesis is that
this problem played a very small role in the impact and fire
regions of the buildings. We are interested in the welding
especially in the core columns.
C: Going back to the wind tunnel testing, Battery Park City
did not exist at the time of the first wind tunnel tests. It
will affect turbulence.
A: Yes. We are considering that.
C: It is very difficult to achieve strain rates higher than
one second to maximum load.
C: I second the concern about wind tunnel testing. It has a
lot to do with the uniformity of wind tunnel loads as opposed
to the variability of actual winds. The actual wind loads vary
from wind tunnel loads and can have a significant effect on
the loading of a structure. This is particularly true if you
look at edge effects and corner effects.
Back to agenda
Project
5 – Reconstruction
of Thermal and Tenability Environment
Dr. Richard G. Gann, WTC Investigation, Project 5 Leader
Dr. William M. Pitts, WTC Investigation, Research Chemist
PRESENTATION
- Pitts (.pdf;
download Acrobat Reader)
Dr. William Pitts presented information on a task of Project
5 of the WTC Investigation, which is an analysis of photographs
and videotapes of the attack on the WTC towers and the subsequent
collapse of WTC 1, 2, and 7. NIST is using photographs, videos,
and other relevant information to develop detailed timelines
for the spread and growth of fires at the peripheries of WTC
1, 2, and 7. More than 6,100 photographs from over 185 photographers
and about 150 hours of videotape (5,726 clips) from more than
20 individuals, news organizations, and documentaries have
been cataloged and entered into a visual image database. Dr.
Pitts presented the times for the major events of September
11, 2001 (plane strikes and collapse times). NIST has timed
the events to within an accuracy of 3 seconds. Dr. Pitts discussed
the relevant visual observations for WTC towers.
There were no questions or comments at the end of Dr. Pitts
presentation.
Back to agenda
PRESENTATION (.pdf;
download Acrobat Reader)
Dr. Richard Gann presented information on the status of the
reconstruction of the thermal and tenability environment for
the WTC towers and WTC 7. The project objective is to reconstruct,
with assessed uncertainty limits, the time-evolving temperature,
thermal radiation, and smoke fields in WTC 1, 2, and 7 for
use in evaluating the behavior and fate of occupants and responders
and the structural performance of the buildings. Dr. Gann pointed
out that due to a lack of physical evidence for this effort,
NIST is relying on computer simulations, experiments, photographic
evidence, and eyewitness accounts. This type of reconstruction
has never been done before, and NIST is redefining the state-of-the-art
in fire and thermo-structural modeling.
NIST has collected and reviewed information on building combustibles,
floor geometry, partitions, and spray-on fireproofing for input
to experiments and modeling. NIST has conducted shake tests
on ceiling systems similar to those used in the World Trade
Center towers to determine what may have happened to these
systems after the buildings were impacted by the aircraft.
In addition, NIST has information on the aircraft contents,
including the mass and location of the jet fuel. Interim findings
are that the mass of aircraft solid combustibles was significant
relative to the mass of the building combustibles in the impact
zone. Interior walls blocked the view through many windows
so it cannot be determined whether there was a fire inside
the building.
Dr. Gann described the workstation fire experiments conducted
to validate the Fire Dynamics Simulator (FDS), a 3-D model
previously validated for tunnel fire temperatures and sprinkler
activation. The results from the experiments showed excellent
agreement with FDS. Dr. Gann stated as a provisional finding
that FDS can be used with confidence to recreate a given WTC
fire event. The series of tests are nearing completion.
Q: Explain the framing system for the ceiling tile you showed
in your presentation?
A: The grid system used for testing is almost identical to
that of the WTC. The rib failed in the first photo as the result
of a single pulse. The second test profile lasted for 10 to
15 seconds with more severe results.
Q: How was a ceiling tile system unique?
A: The tiles in core areas were built to Port Authority specification,
but similar to common tiles. Ceiling tiles in tenant spaces
were built to an odd sized square. The grid systems were
not unique.
Q: What are the
heights of the partition and the ceiling in the test you
showed—relative to the building?
A: The ceiling height was generally about 8.5 feet in the building
(drop ceiling). The partition is 4 to 5 feet tall and consists
of a core material with a fabric covering.
Q: Have you correlated flare-ups in the tests with the experimental
output?
A: We’re not sure that it is a flare-up tied to a single
workstation—probably more than that.
Q: The workstation in the test appears tidy, no clutter. To
what extent do you have data on tenant practices, inspections,
etc?
A: We have talked to Port Authority building managers and tenants.
Many had a clean desk policy. We put paper in cabinets and
on desktops in the test to assess the effect of additional
fuel. We do have accounts that many workstations were kept
neat.
Q: In multiple workstation
burns—given the ventilation
that you have, what heat release would you expect to start
to see an impact for those windows?
A: Fourteen megawatts is the highest intensity peak. We expect
to see differences between test data and models.
Q: There is overshoot, or rather an undershoot, in the fire
test data versus the model prediction at about 500 seconds.
Is that real?
A: The area under the curve in this region is negligible compared
to the area under the total curve. Fuel is a mixture of chair,
computer, carpet, wood, and paper in different locations. I
worry less about the spike.
C: I agree there is very good correlation between the model
results and the test burns.
Q: There is good
agreement in the data. Qualitatively, the model shows a significant
drop when the fuel burns off while
the experiment doesn’t show much drop off. With more
fuel, the drop at the end goes away. Is there a qualitative
difference in the model?
A: I don’t think so. The model has reached zero based
on the fuel loaded into the model at that point. We have the
actual weight loss from the experiment. If we put the actual
weight loss into the model, it picks right up.
C: The weight loss is an output not an input. The weight loss
affects the heat release rate.
C: (NIST) We can talk about that separately, but I don’t
think it is a problem.
C: Agree, it is a minor point.
Q: Regarding mechanical properties of spray-on insulation.
Some results are already reported. The results seem to suggest
significant insulation was removed by the impact of the aircraft.
Is there any way for you to make an evaluation now without
waiting for detailed tests?
A: No. We will get criteria for adhesion. We will also get
a sense of forces from the impact modeling and at that point
we will be able to combine the two and hopefully get a sense
of what happened to the insulation.
Q: Will you take into account outside work?
A: We have information on other tests that have been done.
Obviously, if others have valid data it would be foolish
not to use it.
Q: (NIST) What calculations are you referring to?
A: (Committee Member) For example, some of our structural engineers
at the University of California in San Diego have done tests.
C: (NIST) We would love to see the results.
C: (Committee Member) I will try to get those for you.
Q: Regarding the contents of the aircraft. Is there information
about the amount of their contents remaining in the building
or did most of it leave the building on impact?
A: We have to look at mass and distribution of combustibles
and relate it to the photographic data. This is an issue that
will be worked. We will need to try different variations to
find out.
Q: Going back to the question about the first peak in the
chart, I believe it is where the 2-megawatt burner is extinguished?
A: The burner is turned off in 600 seconds. Both pick up the
burner being turned off.
Q: I am interested in the integration of projects. You indicated
almost a seamless meshing. How did you do it and is anything
preventing greater integration?
A: No, people are willing to do whatever is needed to get the
job done.
C: (NIST) It’s
not all ideal. We find problems and then fix them. They require
different levels of staff and management
attention at different points in time, but everyone has an
interest in doing the right thing.
Q: Did you review NAFEC (Federal Aviation Administration Tech
Center) information on the aircraft interior and the role that
the contents may have had on the fire development?
A: Yes. We have all their input. Some of their insights have
been very helpful.
Back to agenda
Fire-Induced Thermal States and Structural Failure Analysis
Dr. Emil Simiu, Competence Building Project
PRESENTATION (.pdf;
download Acrobat Reader)
Dr. Emil Simiu presented information on simplified modeling
efforts that are ongoing with respect to fire-induced thermal
states and structural failure analysis. Dr. Simiu explained
that no methodology is currently available for evaluating the
capacity of redundant structural systems with fire-induced
thermal effects (?). His group is using state-of-the art methods
to achieve the most effective and realistic possible investigation
of fire-thermal-structural effects. Tools for the analyses
include the Fire Dynamics Simulator for fire representations,
algorithms developed by NIST for calculating temperatures in
structural members due to fire-induced gas temperatures in
the interior of the building, and nonlinear finite element
methods software (ANSYS) for structural analysis. Dr. Simiu
discussed the possible collapse scenarios and the status of
the 2-D and simplified 3-D modeling and analysis.
Q: I have a question regarding two-dimensional structural
model analysis. The sagging of joists took time; the columns
could have heated as well. Around the cavity, if these columns
get heated, they shrink or creep. Is there any effort to assess
this?
A: Absolutely, there are hot spots in the thermal/structural
sense. Some columns may give and the next column may be called
upon to take up the slack. This may lead to a progressive column
failure scenario. The model helps to provide insight into this
issue.
C: It’s important
to integrate the fire and structural models. I encourage
carrying this work further. Breaking windows
can have a large effect on fires. You can go back further and
say windows will break under certain load conditions.
A: It is not easy, but we’re making an effort. You need
to stop the model and change boundary conditions. We are continuing
to look at these aspects of the analysis.
C: (NIST) While this is a 6-month effort in support of the
investigation, the work will continue over a 5-year period
as part of a NIST competence project.
Back to agenda
Project
6 – Structural
Fire Response and Collapse Analysis
Dr. John L. Gross, WTC Investigation, Project 6 Co-Leader
Dr. Therese P. McAllister, WTC Investigation, Project 6 Co-Leader
PRESENTATION (.pdf;
download Acrobat Reader)
Dr. John Gross and
Dr. Therese McAllister presented information on Project 6
of the WTC Investigation, which is an analysis
of the structural fire response and collapse scenarios. The
objectives are to determine the structural response of the
WTC towers to internal fires—with and without aircraft
impact damage—and the structural response of WTC 7 to
debris damage and internal fires. In addition, the Project
6 team will identify the most probable structural collapse
mechanisms for the towers and WTC 7.
Dr. Gross presented progress on the analysis of the WTC towers.
Work is under way to develop finite element models of components
and subsystems for nonlinear thermal-structural analyses. These
include a single exterior panel section, a floor section (80
inch wide), and a truss seat connection. NIST is evaluating
performance under load and elevated temperature. Dr. Gross
presented some results of the preliminary studies with illustrations
from the models. NIST has awarded a contract to develop additional
finite element models of floor systems and the entire tower
structures and to conduct nonlinear thermal-structural analyses.
Dr. McAllister discussed preliminary studies of the effect
of floor removal, elevated temperatures, and load redistribution
on column failure. The effect of fireproofing condition on
the time for smaller columns in the impact area to reach elevated
temperatures within a 1 to 2 hour timeframe was also presented.
She explained that ongoing studies include the effects of load
redistribution as individual columns fail, as well as the effect
of floor removal and elevated temperatures, to gain insight
into component behavior for global studies.
Dr. McAllister described the structural features of WTC 7.
There is a lack of evidence of significant damage to structural,
fireproofing, or fuel systems. The fuel distribution systems
were located between floors 1 to 9. NIST has awarded a contract
to develop component, subsystem, and global models and to conduct
thermal-structural analyses. She stated that NIST has made
progress on collecting and reviewing data such as final design
drawings, specifications, and the fuel distribution system.
Photographs and videos have been reviewed to develop collapse
hypotheses by establishing the initial damage to WTC 7, the
timeline and locations of fire and smoke, and the timeline
and location of exterior signs of collapse (penthouse, windows,
etc.).
C: You keep using
the word simplified when describing your modeling efforts.
You need to make clear what simplified means.
It’s important for people to understand that we simplify
things after we figure out they don’t need to be complicated.
It could be misconstrued. It’s not simplified until after
you have tested certain other things on one end of the extreme
and on the other end to get a feel as you move into 3-D modeling.
You should identify dead ends and areas that you looked into
and that didn’t lead anywhere. People will be looking
at this closely and will want to know what areas were looked
at.
Q: I second the
comment about the excellence of this work. Referring to the
600º C figure versus the gravity load,
I assume that the columns are plumb. Have you combined expansion
of the joints with heating of columns?
A: No, not yet. This is continuing as part of our ongoing work.
We will be looking at deflected columns due to heating of the
floor system.
Q: Is there an overlap
with Emil’s work?
A: There is an overlap in the sense that Emil is looking at
simplified methods to rule in or out possibilities. I would
consider the two as complementary efforts.
Q: Column failure depends on the dead load. Is there a significant
difference in dead load for a column damaged on the 90th floor
versus the 80th floor?
A: Column failure depends on the level of stress; columns on
the 80th floor had a greater cross-sectional area than those
on the 90th floor and so the stress was about the same in both.
Q: In the discussion of force levels, column yielding was
the lowest load and the floor buckling is the highest load.
Did you also look at the bolted connection?
A: We are looking at the column-to-column bolting and determining
yield strengths. We need to do a variety of column analyses,
and we will be combining our analysis of joists with the work
mentioned above.
Q: From what direction was the video of the WTC 7 building
listing shot?
A: The video was shot from the north. The east penthouse is
falling.
Q: What were the locations of the diesel fuel tanks?
A: The tanks were located in the southwest corner.
Q: What about the utility substation enclosures?
A: The transformers were housed in transformer vaults. We’ve
read that silicone fluids were used in the transformers. [Subsequent
follow-up found that oil was used in the utility transformers.]
Q: The transfer trusses are susceptible to thermal loads.
Is there any evidence that the trusses in WTC 7 received any
thermal damage?
A: There is no evidence of heating yet. We need to postulate
hypotheses and evaluate their plausibility.
*Recommendation: The Committee recommended NIST investigate
the fire exposure on the east side of WTC 7 where the cantilever
transfer girders were located because they are susceptible
to failure under fire exposure.
Back to agenda
Project
4 – Investigation
of Active Fire Protection Systems
Dr. David D. Evans, WTC Investigation, Project 4 Leader
PRESENTATION (.pdf;
download Acrobat Reader)
Dr. Evans presented information on Project 4 of the WTC Investigation,
which includes an analysis of the active fire protection systems
used in WTC 1, 2, and 7. NIST is looking at the fire sprinkler
system, including the fire standpipes and pre-connected hoses;
the fire alarm system; and the smoke management system. Dr.
Evans discussed the approach for documenting the design, installation,
and modifications of these systems as well as assessing their
probable performance on September 11, 2001. He briefly reviewed
the results of the NIST fire history study of 12 significant
fires (not including the well-known 1975 fire and the 1993
bombing) that occurred after occupancy in WTC 1, 2, and 7.
Dr. Evans presented the fire alarm system monitoring record
for WTC 7 on September 11, 2001.
Q: You mentioned that you had collected information on sprinklers
in the WTC buildings. I suggest you also look at the One Meridian
Plaza fire. It could be helpful for WTC 7. I thought WTC 1
and 2 were not sprinklered originally? Were they retrofitted
later?
A: Originally, the WTC 1 and 2 buildings were sprinklered only
in the below-ground level areas. However, a program was initiated
by the Port Authority to sprinkler the buildings, and we have
been told that the program was complete.
Q: Is there no information on fires in unsprinklered areas?
A: We have information on all fires responded to by FDNY from
FDNY.
Q: The equivalent and actual fire size?
A: We have all of the FDNY fire response records to look at
for information. For fires in nonsprinklered areas, we considered
other indicators, such as hose line use and fire detector activation,
to determine whether the fire was considered significant or
not.
Q: In getting data on fires, did you screen out non-fire responses?
A: Yes. The total record count only includes fires.
Q: In the 1993 bombing, the control room was demolished. What
was the design of the evacuation and alarm system in the towers
on 9/11?
A: I can’t give all the details, but I understand it
provided an audible alarm plus voice commands.
C: The interviews with occupants may help to clarify this information.
In the past we have seen instances where the alert device can
mask announcements.
Q: A remaining question is in the absence of the ability to
deliver a signal. What is the default capability?
A: We want to know the default message to understand how the
system worked.
Q: In WTC 1 and
2, you stated you don’t have records
of what the alarms did on 9/11, were they destroyed in the
collapse?
A: Yes, we have been told that the records recorded by the
fire alarm system were destroyed by the building collapse.
The fire alarm system records in a building are like “black
boxes” on aircraft, but they aren’t built like
that.
Q: Could the alarms in WTC 7 have been triggered by dust when
the towers collapsed? Did any of the other buildings in the
WTC complex have alarms triggered by dust?
A: That is a possibility. Smoke alarm systems are susceptible
to activation by dust.
Q: Would alarm records from other nearby buildings subjected
to dust from the collapse but not fire be of value in understanding
the alarm system performance?
A: That is a good idea. We will investigate that.
Back to agenda
Project
7 – Occupant
Behavior, Egress, and Emergency Communications
Mr. Jason D. Averill, WTC Investigation, Project 7 Leader
PRESENTATION (.pdf;
download Acrobat Reader)
Mr. Jason Averill presented an update on Project 7 of the
WTC Investigation, which includes an analysis of occupant behavior,
egress, and emergency communications on 9/11. The focus of
the presentation was on collecting data through first-person
accounts, including 800 telephone interviews, 350 face-to-face
interviews, and 10 focus groups. Mr. Averill indicated that
the NIST study, using a multidisciplinary approach bridging
expertise in a new and innovative way, is one of the largest
evacuation studies ever conducted. The required approvals and
training are completed, and the first interviews are under
way. He presented the methodology for identifying possible
volunteers to be interviewed.
Q: What is driving the limit on the number of face-to-face
interviews that will be done? Is it budgetary or something
else?
A: It is strictly a technical decision. We have taken a look
at some of the areas that we want to conduct face-to-face interviews
in, and those were in the white paper that was previously issued.
The number has changed somewhat and that is strictly a function
of the fact that we probably had overestimated initially the
numbers of people that we would need to interview in particular
sections of the building. If it were an issue that we needed
a few more interviews, we could find a way to make that happen.
We looked at the areas and said that if we have x number of
interviews of this type is that enough for us to answer the
types of questions we have. We feel that we can accomplish
our objectives with this number of interviews.
Q: You are gathering observational data. Why wouldn’t
you talk to everyone if you could?
A: In the interview process, you reach a point of diminishing
returns. We are planning to talk to as many people as we can
who were in the impact zone.
Q: If there were an event in the future with a large number
of people to interview, like we had at the World Trade Center,
how long would it take to procedurally get something in place
to support the interviews?
A: In the future, we will view interviews as evidence collection
procedures, not as human subject research. We will still have
a procedure to protect interviewees. More systematic studies
will likely require a pre-cleared human subjects protocol.
C: It is imperative that NIST have a standby protocol in place
for a quick response to an event. A task force should be assigned
to make that happen.
Q: I’m concerned about telephone interviews. Elaborate
on the procedures to get a statistical representation of the
population. People have to be selected randomly. You said that
a great deal of letters were mailed out. But we don’t
know in advance how many recipients were in the building. We
haven’t defined the universe. How do you ensure a random
sample with an undefined universe?
A: The buildings were divided into zones using the mechanical
floors as the divider so that we have a low, medium, and high
strata in WTC 1 and 2. We then divided it up into tenants with
40 percent or more of the occupied floor area and those with
many smaller tenants. We have the badge list, which would be
a superset of people with access to the zones.
A: The frame is the best surrogate you can get for your population.
In most surveys, you are dealing in some way with a frame that
is less than perfect. We tried to get as close to perfection
as possible. The badge list is the best source of data. There
are almost 94,000 records. We were able to eliminate 33,000
records for people that were not in WTC 1 or 2. We also matched
known deceased. That left us with 45,000 records. We then divided
the list by building. We took 13,000 from each building as
a random sample. We matched 75 percent of the 13,000 using
a Lexis-Nexis database. Twenty-five hundred from each building
were randomly selected and sent a letter. Letters were forwarded
where possible; undelivered letters were returned. We are getting
calls from persons who received letters, but were not in the
buildings on September 11. We eliminate these people from the
list of potential interviewees. We will do the same when calls
are made. We’re taking as much care with samples as possible
and keeping track of the results.
Q: In the past, you have mentioned the integration of the
other studies that are ongoing with this study. What is the
status?
A: We are going into the field; Columbia University is at a
different phase. We’ll formally get together and discuss
what we’re finding. This is a Federal investigation,
and we have to figure out how to integrate results.
C: (NIST) The two studies are complementary. The Columbia focus
is on sociology and demographics, ours is on evacuation and
egress. There’s synergy between the two studies, but
they have to go forward in and of themselves. The intent would
be to share results and findings when they become available.
Back to agenda
Project
8 – Fire
Service Technologies and Guidelines
Mr. J. R. Lawson, WTC Investigation, Project 8 Leader
PRESENTATION
(.pdf;
download Acrobat Reader)
Mr. Randall Lawson presented an update on Project 8 of the
WTC Investigation, which includes an analysis of fire service
technologies and guidelines. The tasks of this project include
data collection, field interviews, and re-creation and analysis.
Mr. Lawson discussed the interviews that will be held with
the Fire Department of New York City, the New York City Police
Department, and the Port Authority police and security staff.
NIST has analyzed most of the radio and telephone communications
tapes in its possession. Mr. Lawson reviewed some of the noteworthy
radio calls, including a timeline for the dispatch/arrival
of emergency response units. He stated that although the radio
systems appeared to work well during normal operations, roughly
one-third to one-half of the radio communications were not
completed due to surge load conditions.
Q: You’re
looking at dispatching and documenting the units arriving
on the scene. Many units responded that were
not dispatched. Can you quantify the impact this may have had
on communications?
A: Many did not show up in the radio traffic. It is hard to
document.
Q: Could you get qualitative data from the interviews?
A: Yes, we do have an approach to try to gauge that.
Q: You made a statement about two orders for evacuation. Where
did the call come from for evacuation? Did it come from the
field?
A: We are trying to determine the location of the person who
made the call, and we want to understand what is normally done
with such a call.
C: (NIST) We do not want to identify the individual. It was
an officer with responsibility.
Back to agenda
Project
3 – Mechanical
and Metallurgical Analysis of Structural Steel
Dr. Frank W. Gayle, WTC Investigation, Project 3 Leader
PRESENTATION
(.pdf;
download Acrobat Reader))
Dr. Frank Gayle presented an update on Project 3 of the WTC
Investigation, which includes a mechanical and metallurgical
analysis of structural steel recovered from the WTC towers.
The 236 pieces of steel from WTC 1 and 2 have been catalogued
and identified; NIST has samples of all 14 grades that were
used in the towers. Dr. Gayle reported that the steel has been
analyzed to determine local failure mechanisms and repeated
patterns of fracture/failure. The photographic evidence was
enhanced and compared with the recovered steel. Testing for
metallurgical and mechanical properties is under way, and tensile
properties have been determined for all perimeter columns.
Q: I’m curious.
Using a high number of different steel grades is kind of
unusual. What was the reason for all these
different grades of steel? Was it for architectural purposes?
The slide showed that the stiffness of the spandrel takes the
load. It really does distribute the load. What was the reason
for the number of grades? Was it to keep the columns the same
size for architectural purposes?
A: The exterior part of the columns was the same size. My understanding
is that the large number of steel grades was used to keep the
weight down.
Q: Usually the dead weight of steel is not that important.
First you set the architectural enclosure so you can use the
most efficient and cost-effective solution. I suspect fine-tuning.
Did they vary the steel weights around the perimeter at a level
or does it vary from top to bottom?
A: It varies everywhere and in every which way. It tends to
be ¼-inch steel for the perimeter columns in the upper
floors.
Q: Where does the load really go? Are there any flaws in using
high-strength steel?
A: We are looking at this issue. We’ve read that the
design tried to make the stresses in the columns and the core
equal. This is part of the baseline analysis.
C: (NIST) We haven’t yet found the rationale for using
the many high-strength steels. We’re trying to determine
the rationale.
Q: Is there a difference in weldability? Are there any subtle
metallurgical issues?
A: It is an issue with high-strength steel. There has been
a lot of work done by the Japanese on weldability [referring
to the perimeter columns, where steel was supplied by Yawata
Steel].
Q: How are you adjusting the ASTM loads with the dead loads
of the building?
A: There’s a factor, maybe 3.5 kips per square inch or
something on that order, and we have one for each steel to
take it to a static test. When you have different strain rates,
in this case for the estimated properties, we took all the
data we had from the literature and accounted for the strain
rate used in order to adjust them to the properties that you
would have measured at the strain rates they used for mill
testing. In that case, we probably have to modify up some test
results because they tested a faster strain rate at the steel
mills, but you have to have some equal basis to do that. But
if you have a static load in a building, you may want to bring
that down to account for the strain rate.
C: I wish you had told Bob Hanson or me that you had to do
that. We did a lot of work following the Northridge earthquake,
and there are reports that would give you that.
C: The report was FEMA 355.
C: (NIST) We have a complete set of the documents here at NIST
and are using them.
C: Regardless of what data you are going to generate, I would
have a problem using these numbers for the Project 2 analysis.
There is too much variability with data from different mills,
etc. I encourage using it as the reference point for the analysis.
Spend more time doing literature searches and getting the typical
properties for steel and use that for materials properties.
Take the mean of the error bar.
A: We are using test data generated by NIST as a checkpoint
to confirm that we don’t have anything out of the ordinary.
We have taken your advice on the use of data reported in the
literature.
C: I have a problem
justifying the need for triaxiality data on welds. I don’t
think it is a triggering mechanism and will take too long
to complete.
Back to agenda
Public Comment Period
Mr. Fitzgerald stated the ground rules for public comments.
Each speaker has 5 minutes to address the Committee. Members
of the public may submit their comments in writing at the meeting
or at any time. Mr. Fitzgerald read into the public record
the comments of Mr. Donald Bliss, who submitted a prepared
statement.
Donald
Bliss, National Association of State Fire Marshals’ Partnership
for Safer Buildings
STATEMENT (.pdf;
download Acrobat Reader)
Mr. Fitzgerald called the first speaker to the podium, Mr.
Arthur Scheuerman.
Arthur Scheuerman, retired FDNY Battalion Chief
I appreciate the
opportunity to speak to you today. The main problem as I
see it is building codes. I can’t believe
that they are still reducing the timeframes for how long columns
and beams must be protected. You all are doing a great job.
I can’t believe the job you all are doing.
I have a different
opinion on the collapse mechanism. I read a report by a British
engineer, Usami. He comes to the opposite
conclusion that the columns failed from a sudden release of
compression when the columns buckle. In other words, as the
columns are being pushed out, they’re building up compression
and when they buckle, the sudden release of the column pushes
them in further and they collapse. His graphs show just the
opposite. His graphs show that the floor joists pull the columns
inward as they sag. I don’t know whether it’s from
thermal bowing or loss of strength, but his report is very
interesting. As shown in the overhead, the columns are very
stiff, so floor 4 is under compression and floor 3 is in tension
because this is acting just like a lever. The two buckling
floors are putting the columns in floor 4 under compression
and floor 3 is under tension. There were several reports or
pictures of an explosion out of the side of the building. That,
I think, was floor 3 or like the 79th floor exploding outward
and pulling the floor with it. It may have disconnected from
the core columns. Usami did a finite computer element analysis,
like you did, and concluded that the buildings failed as the
columns collapsed inward. In no case do the columns go outward.
Thank you.
Mr. Fitzgerald called the next speaker, Mr. Ray Scott.
Ray Scott, Battalion Chief, Prince William County, Virginia
STATEMENT (.pdf;
download Acrobat Reader)
Back to agenda
Mr. Fitzgerald thanked the presenters, attendees, and speakers.
He adjourned the meeting at 5:40 p.m.
December 3, 2003
Back to agenda
Mr. Fitzgerald called the meeting to order at 8:10 a.m.
Status of The Station Nightclub Investigation
Dr. William L. Grosshandler, Chief, Fire Research Division
PRESENTATION (.pdf;
download Acrobat Reader)
Dr. William Grosshandler is leading the NCST investigation
of the fire at The Station nightclub that occurred in West
Warwick, Rhode Island on February 20, 2003. He presented information
on the status of the investigation. NIST has about 75 percent
of the building geometry identified, including the floor plan,
vent locations, doors, windows, and ceiling heights. NIST is
still seeking more construction drawings of the building and
fire alarm system plans as well as photographs or videos of
the outside or inside of the building prior to the fire.
Dr. Grosshandler described the tests that have been conducted
thus far, including samples of 8-foot by
4-foot wood panels covered with a common non-fire-retarded
foam. Videos recorded the flame spread in an exterior and interior
corner arrangement and various measurements were taken. NIST
is also analyzing the evacuation process by using commercially
available software models. Other tasks include documentation
of emergency response to determine how the fire department
was notified. NIST is collecting emergency response data in
cooperation with the local fire department to document procedures
and operation of equipment.
C: You indicated that it is difficult to get information on
the wall covering. From the viewpoint of improvement to codes,
it is of interest to do tests of fire-retardant foam to the
extent funds are available. You may be able to learn something
by varying the parameters.
C: (NIST) Even if
we can’t get the exact foam used in
the club, it is important to move forward. There is a lot to
be learned in any case. There are no funds for additional full-scale
tests. There are no codes for use of this type of material
as a wall covering (fire-retardant or not); maybe looking at
the fire spread is worth doing. We’ve been doing this
for many years. We need to be able to reproduce the fires better
than we’ve shown. We have not tuned the experiments.
We’re not moving at the pace we would have liked. We
have waited for access to data. However, we feel we are still
in a position where we will be able to apply findings with
confidence.
Q: One of the criteria
you mentioned for when NIST would be involved in an investigation
was the quality of the analytic
team—it will never be the case where a state or local
investigation could match NIST’s qualifications.
A: This was taken from the implementation rules. There are
statewide, county, and local investigations of the Chicago
fire. We have confidence they will reach the same conclusions
we would. That is one of the reasons we chose not to investigate
the Chicago fire.
C: Even if there are other investigations ongoing, they may
have different objectives relative to an NCST investigation.
I understood that the Chicago decision was mostly a resource-driven
decision.
C: (NIST) Resources were not the only driver.
C: (NIST) We want to make a difference and not duplicate other
efforts. We want to be able to make a broad recommendation
that would affect national practices.
C: I would argue
that all of those conditions are met in Chicago. Another
point, it should be up to the team to conduct interviews
and to gather all the data. Assume that information is not
available from other sources in a timeframe that is useful.
It should be in the team’s mind to obtain information
directly in any future investigation.
C: (NIST) You’re right, certainly we’re learning.
We need to start gathering information from day one.
C: From a social
science point of view, this (the Rhode Island nightclub fire)
is an important event. Evacuation and the thought
processes of occupants are important to understand. Panic is
a controversial subject and there seems to be an assumption
that it played a role here. It will be very important to look
into the extent that it did happen. I’m not saying there
was panic; I’m not saying there wasn’t. As we saw
on the film, there was a delay in the response of people as
they were normalizing. Maybe they thought fire was part of
the act. It is important to have good social science input
when people are interviewed. I would encourage NIST to seek
out that kind of support when developing the questions that
will be asked. Beyond that, NIST should have in-house social
science capability for conducting these kinds of investigations.
Q: (NIST) Agreed. However, interviews will be investigative
and are not addressing these issues. In this case, we don’t
have the funds or access to do what you suggest and will be
unable to fulfill this desire within the timeframe available.
Could such a study be done as a follow-up, say six months from
now?
A: (Committee Member) interviewing the survivors? Yes, it could
be done and it’s essential. This is central to understanding
decision processes and group dynamics in these rapid evacuations.
As you aptly pointed out in your presentation, current models
don’t capture this type of behavior. How do we improve
them if we don’t get a deeper understanding of the behavior
involved?
C: We may need to call upon you when we draft that part of
the report to make sure we get the right recommendation.
C: (NIST) We are operating on an ad hoc basis. Until we get
appropriated funding, this is about where we are. Other capabilities
are necessary to conduct investigations. We need to take these
recommendations seriously, and of course, we also need the
resources to put those recommendations into action.
C: We wouldn’t expect this in 2004. These recommendations
should be considered in the long range. We have the responsibility
to help in the overall competency of future investigations.
*Recommendation: The Committee recommended NIST develop in-house
social science capabilities to perform egress studies for future
investigations.
Q: There is no competent model for the behavior of people
in fire evacuations. This makes Project 7 of the WTC Investigation
so important (first-person interviews). Can you tell us the
number of survivors in the Rhode Island fire?
A: There were 430 people in the club. One hundred people died.
There were 330 survivors.
Q: Do you have information on when the building was constructed
and for what purpose?
A: The building was originally a restaurant.
A: Yes. It was converted to a nightclub in 1980 or 1981.
A: (Committee Member) According to the public records, the
building was constructed in 1950. Anecdotally, the initial
building may date back to World War II.
Q: The building may actually date back to 1941 or 1942. Were
there changes to the floor elevation?
A: There was a subfloor added near the front of the building,
and the stage was added at a later time. The building permits,
which are filed publicly, provide some information, but don’t
match the structure itself.
Q: The plan is presently
for about one investigation per year. Historically, that’s probably good. If you have three
events in a year that are within what we’re supposed
to do, how do you choose which one to investigate?
A: The approach was to address upset conditions mostly based
on natural phenomena that statistically would average out to
be one a year. This does not take into account manmade events
such as terrorist acts and other events. There is a lot of
concern that NIST would investigate beyond what the act envisioned.
If we had three serious events in a given year, we would request
the authority to investigate all events within the scope of
the act.
C: I would like to see NIST have the funds and manpower to
support three investigations, if there are that many in a year,
and want to recommend that funds be made available.
C: I have a comment with regard to the safety of first responders
that is also part of the charge. Future investigations should
address communications criteria. It may have been a problem
at The Station. This is an ongoing issue that should be highlighted.
In Chicago, there was great confusion on the fire ground.
C: (NIST) NIST has been asked by the Governor of Illinois
to assist with the Chicago fire, and we will assist to the
extent that our limited resources allow.
Back to agenda
NCST Act and Requirements
Dr. James E. Hill, Acting Director, Building and Fire Research
Laboratory
Dr. James Hill discussed the NCST rules published in 15 CFR
Part 270. When the act was passed, NIST was told by Congress
to publish rules within 90 days. The final rule addressing
the collection and protection of information was published
in May 2003. An interim final rule with additional procedures
was published on November 28, 2003, requesting public comment
(68
FR 66703 pdf file). Dr. Hill asked the Committee to comment
on this rule during the public comment period on the Federal
Register notice, and said that NIST would also welcome comments
individually. He began the discussion by highlighting four
items in the November 28 interim final rule.
1. Section 270.2 adds a definition of credentials. This includes
photo identification and badges, deemed appropriate by the
Director similar to the National Transportation Safety Board.
2. Subpart B addresses the establishment and deployment of
teams generally. The expectation is that NIST will conduct
one investigation per year. NIST could investigate more than
that.
C: More realistically, I think we are looking at three to
four investigations per year of the scale of The Station nightclub
fire and one at a fraction of the scale of the World Trade
Center. It may be better to put this into the rule to help
with public expectations.
C: (NIST) In terms of the procedures, there are things that
we can do as NIST and things that you can do as an Advisory
Committee. Perhaps these thoughts could be compiled and included
in your report.
C: We prefer incorporating that in our report.
C: (NIST) I’m not sure I’m in full agreement with
the earlier comment on three to four investigations. The Station
nightclub fire is a once in a generation event. It depends
upon your interpretation. Three to four may benefit from our
investigation, but it’s not clear that that was the intent
of the act.
3. There is a section called Preliminary Reconnaissance. This
section simply gives NIST the flexibility to establish a team
before doing preliminary reconnaissance or send staff out before
a team is established.
4. On page 66705, Part 270.102 sets the conditions to establish
and deploy teams. Paragraph (a) comes directly out of the act.
Paragraph (a)(1) deals with major failure of one or more buildings
due to a natural event, a fire that resulted in a major building
failure, failure of a building at less than its design basis,
and an act of terrorism that results in a Presidential declaration
of disaster. Then the third element is spelled out in the next
paragraph, which states that the investigation will likely
result in significant or new knowledge or building code revision
recommendations to reduce public risk or economic loss.
Some of the issues that came up as NIST was pulling together
this rule are stated, whether there are sufficient funds available
to support the investigation, whether the investigation warrants
the advanced capabilities and experience of a team, if the
cause is readily apparent, whether the investigation is likely
to result in relevant knowledge, and whether the investigation
will be duplicating some other investigation.
C: Shall we discuss this now?
C: (NIST) The rulemaking
schedule versus the report to Congress—how
does the report affect rulemaking?
C: The Committee should respond separately on the rule in a
letter to Dr. Hill.
C: (NIST) the concern is that the Committee has had the rule
for only one week.
C: (NIST) The Advisory Committee as individuals are free to
comment on the rule. The diversity of comments may be better
than a consensus. As an Advisory Committee, consensus advice
must be reached in public session.
The Committee took a break to read the interim final rule.
When the meeting resumed, Dr. Hill went through the interim
final rule section by section, asking the Committee members
for comments.
C: (NIST) Refer to the second page, middle column toward the
bottom. Any issues on credentials? None. The third column,
one-third of the way down. Are there comments on natural disaster
frequency?
C: I suggest replacing
the last “than” with “more
than.” If you look at earthquakes, in Northridge, there
were four to five classes of building structures that could
warrant investigation. Consider the number of events versus
the number of investigations.
C: I second that comment.
C: (NIST) The statement refers to building failures, not investigations.
C: As well as potential for loss of life.
C: Integrate potential. Resource and organizational planning
should assume three to four investigations at The Station level
over more serious events.
C: (NIST) There was a suggestion to say “more than”.
C: Three to four is more than one. That’s okay by me.
I can live with “more than.” Resource planning
is a separate issue.
C: Suggest we use the words “more than.”
C: (NIST) It may be more appropriate to say two to three.
C: Bound it. Say less than 10.
C: (NIST) Setting expectations is the issue.
C: I would suggest several times per year.
*Recommendation: The Committee recommended that wording in 15 CFR 270.100(a)
be changed to read: Historically in the United
States building failures from fires, earthquakes, hurricanes,
tornadoes, and other disasters that have resulted in a substantial
loss of life or that posed significant potential for substantial
loss of life have occurred “several” times per
year.
The recommendation was agreed to unanimously by the Advisory
Committee.
Section
270.101, Reconnaissance. No issues.
Section 270.102, Conditions for Deployment.
C: On (iv), the Federal Response Plan, it is about to be superseded
by the National Response Plan.
Q: Section 270.101. Meaning of a team?
A: Team is the team to do the reconnaissance.
C: The same team would do the investigation?
A: The section gives the flexibility to either do reconnaissance
or establish an investigation team.
C: In section 270.102, paragraph (a), the list does not capture
the idea of investigating building fires. Fires may have potential
for loss of life without building failures.
C: (NIST) The logic goes hand-in-hand with everything else
here. The incident would have to meet the loss of life plus
a type of fire criteria.
C: (NIST) Section 100, paragraph (b) defines a building failure.
C: The criteria may be too restrictive on when a team may be
active.
C: (NIST) This section is out of the act.
Q: (NIST) Are specific scenarios not listed?
C: The Chicago high-rise had the potential for loss of life
without building failure.
C: The earlier suggestion may be the way out.
*Recommendation: The Committee recommended that wording in 15 CFR 270.102(a)(1)(ii)
be changed to read: “a fire
that resulted in a building failure of the building of origin
and/or spreads beyond the building of origin.”
C: Under the list of five items that the Director will consider:
number three (15 CFR 270.102(b)). If the technical cause is
readily apparent, sometimes the cause is not the issue. Understanding
is needed to have some impact on codes, standards, and practices.
Add the appropriate mitigation measures clause.
C: There were comments during the Rhode Island presentation
relative to duplication [of local investigations].
C: (NIST) The intent is not to duplicate state or local investigations.
C: That is highly unlikely. I recommend striking that requirement.
C: I support that.
C: I don’t think you want a clause like that in the rule.
*Recommendation: The Committee recommended that 15 CFR 270.102(b)(4)
be deleted because it is highly unlikely that the NIST investigation
would duplicate local or state capabilities.
*Recommendation: The Committee recommended that a new section
15 CFR 102(b)(4) be added that the Director will consider whether
an investigation is likely to result in relevant knowledge
for mitigation of the building failure.
C: First page, middle
column. Purpose of investigations (15 CFR 270.101(b)(1)).
Other purposes. Add: “…, safety
of building occupants, and it emergency egress and response
measures.” Life-safety is a preeminent criterion. NIST
is charged with looking into egress issues and activities of
first responders.
C: I support that. It is consistent with section 270.100.
C: On page 66705
(15 CFR 270.104(b)(5)): after “civil” add
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