Feds: Heat Caused Fatal Bridge Collapse
Record heat was to blame in a fatal train derailment last summer that collapsed a bridge, sending the entire structure and dozens of loaded freight cars crashing onto the street below, a federal report found.
On July 4, 2012, a Union Pacific coal train traveling about 15 feet south of the Shermer Road Bridge along the Glenview-Northbrook border in Illinois derailed, sending cars and the bridge plummeting to the road below.
The Federal Railroad Administration released its Accident Investigation Report on July 19, which determined the probable cause of the derailment was "thermal misalignment of the track due to an elevated rail temperature." The temperature was a record high of 103°F for the northern Chicago suburb of Northbrook.
Burt and Zorine Lindner, ages 69 and 70, respectively, were driving under the bridge at that moment and were killed.
Originally, it was thought that no one had been hurt in the collapse. However, when crews began to sift through the wreckage the following day, they discovered a car with two bodies under the rubble.
Abnormally High Temperatures
At approximately 1:30 p.m. CT on July 4, 2012, 32 freight cars derailed, each carrying an average of 75 to 85 tons of coal, piling up on top of the overpass, which then collapsed onto the street below.
Due to the abnormally high air temperature, the rail at the point of derailment was in compression, making a track buckle more likely to occur, the FRA report concluded.
The 86-foot-long bridge structure consisted of two open deck, steel spans per track. Each track had a seperate superstructure, supported by separate steel pile piers in the center of the road and concrete abutents at each end.
Under the bridge is Shermer Road, a two-lane road with one lane in each direction on either side of the center bridge pier. After the accident, the only remaining portions of the underpass were the two concrete abutments and a small portion of the steel pile pier, according to the report.
It appeared that the span anchor bolts had been sheared off or pulled out. Three of the four steel spans and other portions of the bridge were found in the wreckage. According to the FRA report, none of the beams showed evidence of serious corrosion.
Morning Problem Reported
On the morning of the accident, a UP signal maintainer responded to a reported signal problem at the track when he spotted an anomaly in the south side of the track on the Shermer Road Bridge. He walked across the bridge to investigate and saw what he believed to be a bent weld. Since the signal maintaner was not qualified in track inspection, he called a track supervisor to report what he saw.
The track supervisor was already working his way down the track performing inspections, but he never made it to the bridge before it collapsed.
|Reader photo by Tony Nielson submitted to the Chicago-Tribune|
Over a year after the accident, the road where the bridge collapsed remains blocked off.
Because of the extremely hot temperatures in the area, the train was operating at 38 miles per hour; maximum allowable speed under the heat restriction was 40 miles per hour.
Two crew members were on the train, and both were subjected to toxicological testing, which came back negative. The FRA also concluded that operator fatigue was not a factor in the accident.
The estimated track and structure damages totaled $3,704,500 and estimated equipment damage was $1,514,329, according to the FRA report.
Over a year since the accident, the road remains blocked, frustrating local business owners. Union Pacific selected a contractor to build the new bridge earlier this month. Construction is expected to last until at least December.