Numerical Simulation of the Caldecott Tunnel Fire, April 1982.
Numerical Simulation of the Caldecott Tunnel Fire, April
1982.
(444 K)
McGrattan, K. B.
NISTIR 7231; 21 p.
, December 2005.
Keywords:
tunnel fires; tank trucks; simulation; geometry; thermal
environment; gasoline; spill fires; fire models;
experiments; highways; gas temperature; surface
temperature; wall temperature
Abstract:
In the early morning of April 7, 1982, a gasoline tanker
truck travelling westbound in the No. 3 bore of the
Caldecott Tunnel overturned and caught fire as a result
of a multi-vehicle accident. The tunnel connects Oakland
andWalnut Creek, California. The National Transportation
Safety Board (NTSB) and the California Highway Patrol
(CHP) conducted investigations of the accident. In
addition to a detailed account of the events leading up
to the fire, their reports contain information about the
tunnel, the damage to the vehicles, walls and fixtures,
and various other details. As part of its on-going study
of the safety of waste transportation casks, the US
Nuclear Regulatory Commission (NRC) requested that the
Building and Fire Research Laboratory of the National
Institute of Standards and Technology (NIST) perform
numerical simulations of the fire to assess the thermal
environment within the tunnel. The results of the
simulations were used as boundary conditions for a
detailed thermo-structural analysis of a transportation
cask. The simulations described in this report were not
intended to replicate every detail of the fire, since
the information about the gasoline spill, tunnel lining
materials, etc., was not known to a high enough level of
certainty to permit an exact reconstruction of the
event. The approach taken was to use what information
was known about the incident as a starting point for the
calculations, and then to vary the unknown parameters to
ascertain the range of possible outcomes. A similar
study to that presented here was conducted by NIST to
estimate the thermal environment of the Howard Street
Tunnel in Baltimore, Maryland, following the derailment
in July 2001 of a freight train and the burning of
spilled tripropylene and the contents of surrounding
rail cars. The similarities and differences between the
Caldecott and Howard Street Tunnel fires are discussed
in this report.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899