Detailed Numerical Simulation of the Graniteville Train Collision Page: 2 of 6
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
WSRC-MS-2005-00635
October 2005
Detailed Numerical Simulation of the Graniteville Train Collision
R. L. Buckley
Savannah River National Laboratory
Aiken, South Carolina 29808 (USA)
robert. buckley @srnl.doe.gov
Abstract-An unfortunate accident occurred in Graniteville, South Carolina on 6 January, 2005 when a train carrying a
variety of hazardous chemicals collided with a stationary train parked on a siding rail (spur). The Savannah River National
Laboratory (SRNL) runs prognostic atmospheric simulations of the Central Savannah River Area (CSRA) on an operational
basis in the event of such airborne releases. Although forecast information was provided at 2-km horizontal grid spacing
during the accident response, a higher-resolution simulation was later performed to examine influences of local topography
on plume migration. The Regional Atmospheric Modeling System (RAMS, version 4.3.0) was used to simulate meteorology
using multiple grids with an innermost grid spacing of 125 meters. This report discusses comparisons of simulated
meteorology with local observations and applications using two separate transport models. Results from the simulations are
shown to generally agree with meteorological observations at the time. Use of a dense gas model to simulate localized effects
indicates agreement with fatalities in the immediate area and visible damage to vegetation.I. INTRODUCTION
The unfortunate accident involving two trains in
Graniteville, South Carolina during the early morning of 6
January, 2005 resulted in nine fatalities. A stationary train
sitting on a siding rail (spur) was impacted by another
train carrying a variety of hazardous chemicals, including
liquid chlorine (Cl2). The switching mechanism was
inadvertently set to send trains to the spur, rather than
northward and out of town. At 2:40 LST (0740 UTC), the
train carrying these chemicals collided with the stationary
train resulting in train derailment and compromise to one
the cars containing the Cl2. Upon contact with the
atmosphere, the chlorine vaporized and thus became an
airborne threat to the immediate vicinity.
The Savannah River National Laboratory (SRNL)
runs prognostic atmospheric simulations of the Central
Savannah River Area (CSRA) on an operational basis in
the event of such airborne releases. Forecast information
available at 2-km horizontal grid spacing was available
during the time of the incident and used as a supplemental
aid to consequence assessment. However, because the
accident scene is situated in a valley where topography
could strongly influence the movement of a dense gas
(Cl2), it was decided to run more detailed simulations of
the wind conditions around the time of the incident. The
Regional Atmospheric Modeling System (RAMS, version
4.3.0)1 was used to simulate meteorology using multiple
grids with an innermost grid spacing of 125 meters. This
paper discusses the model attributes, comparisons of
observed and modeled wind direction and speed during
and after the accident, as well as application of this wind
information to two separate transport models.II. DESCRIPTION
A collision involving Norfolk Southern Railroad
trains occurred at 02:40 LST (0740 UTC), 6 January 2005
in downtown Graniteville, South Carolina (33.5617 N,
81.80880W). Typical SRNL simulations are run every 3
hours and provide 6-hr forecasts of meteorology in the
Central Savannah River Area (CSRA) at an inner grid
spacing of 2 km. A prognostic atmospheric model
(RAMS) is used to generate three-dimensional
atmospheric conditions, with initial conditions provided
by the Rapid Update Cycle (RUC). Surface conditions
require land-use features such as topography, vegetation
type, and soil type. Variable input soil moisture
conditions are also used. The lowest atmospheric level
above ground is -20 m. This grid system is designed for
emergency response needs at the Savannah River Site
(33.256 N, 81.7500W), located to the south-southeast of
Graniteville by -30 km (see Fig. 1).
Since the train collision occurred in a valley oriented
in the north-south direction and involved dense gas
releases to the atmosphere, it was decided to run a much
higher resolution RAMS simulation in an attempt to
capture the near-surface wind fields very near the crash
site. The original two-grid system was modified to
incorporate a third and fourth nested grid at 500 and 125-
m horizontal grid spacing, respectively. In addition, the
vertical grid spacing was reduced such that the lowest
vertical level above ground for the two outer grids was ~
15 m AGL, while for the inner two grids it was -7 m
AGL (resulting in 14 atmospheric levels below 300 m).1-
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Buckley, R. L. Detailed Numerical Simulation of the Graniteville Train Collision, article, October 24, 2005; Aiken, South Carolina. (https://digital.library.unt.edu/ark:/67531/metadc876766/m1/2/: accessed April 23, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.