Experiments and Modeling of Multiple Workstations Burning in a Compartment. Federal Building and Fire Safety Investigation of the World Trade Center Disaster.
Experiments and Modeling of Multiple Workstations
Burning in a Compartment. Federal Building and Fire
Safety Investigation of the World Trade Center Disaster.
(5569 K)
Hamins, A.; Maranghides, A.; McGrattan, K. B.;
Ohlemiller, T. J.; Anleitner, R. L.
NIST NCSTAR 1-5E; 158 p. September 2005.
Keywords:
World Trade Center; high rise buildings; building
collapse; disasters; fire safety; fire investigations;
terrorists; terrorism; experiments; compartments; fire
behavior; mass loss; heat release rate; gas temperature;
carbon monoxide; carbon dioxide; oxygen; vapor phases;
thermal environment; combustion; fire models; flame
spread
Abstract:
A series of large-scale experiments were conducted in
the National Institute of Standards and Technology
(NIST) Large Fire Laboratory from November 4 to December
10, 2003, to assess the accuracy with which the NIST
Fire Dynamics Simulator (FDS) predicts the thermal
environment in a burning compartment. In addition, the
experiments established a data set to validate
prediction of the heat release rate associated with the
burning of office furnishings similar in type to those
found in the World Trade Center (WTC) towers. The
experiments were designed to recreate aspects of the WTC
fires including issues associated with limited
ventilation, fire spread and growth on real furnishings,
and the effects of debris and jet fuel on the heat
release rate of fires burning under conditions believed
to be similar to those occurring on September 11, 2001.
Within a steel-frame compartment (nominally 3 m by 7 m
by 4 m high) lined with calcium silicate boards were
placed three computer workstations (office modules or
workstations) composed of tables, desks, fabric-lined
partitions, carpeting, a task chair, paper-filled filing
cabinets and bookshelves, as well as a personal
computer, keyboard, and monitor. The same configuration
of furnishings was used in all experiments except one in
which the workstation components were rearranged into
component pieces to represent a disrupted non-standard
configuration, which may have occurred as aircraft
entered the WTC structure. In some of the experiments,
several liters of jet fuel were distributed about the
workstation components or ceiling tiles within the
compartment until a large percentage of the horizontal
surfaces of the furnishings were covered. A 2 MW
hydrocarbon fire generated by nozzles spraying onto a 1
m by 2 m pan was used to ignite the compartment
furnishings. The fuel was a commercial blend of heptane
isomers. Six fire experiments were conducted and nearly
70 instruments were used to measure a number of
important variables including the heat release rate of
the fire and the vertical profiles of gas phase
temperatures.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899