Did MnDOT miss a potential failure?
On July 28, Mark Rosenker, chair of the National Transportation Safety Board, said that his agency has not ruled out the possibility that MnDOT missed a signal that led to the I-35W bridge collapse. Rosenker said photos of the gusset plates, which were one-half-inch thick and warped, were overwhelmed with the weight on the bridge.
His comments reversed statements he gave in January that MnDOT officials could not have known about the defected gusset plates.
The final report, to be released within 90 days, will address whether MnDOT approved the loading of heavy construction materials on the bridge, as well as whether high temperatures and vibration from repaving work and heavily corroded bearings played a role in the collapse.
MnDOT has a new process for bridge inspection to ensure that inspection reports receive internal review by specifically designated personnel.
A walk to commemorate the first anniversary
On August 1, 11 a.m., about 400 people attended an interfaith service at the Basilica of St. Mary, Minneapolis, to remember the victims of the I-35W bridge collapse. The service began with Buddhist monks’ chants, followed by a Native American drum circle and prayers from Islamic, Jewish, Hindu, and Christian leaders.
At 5:30, about 500 people – including state political leaders, bridge workers, police, medical personnel, families of the victims, and Minnesota citizens – followed a procession of fire trucks, ambulances, police vehicles, and the Minneapolis Police Pipe Band as they marched on West River Road from Gold Medal Park to the Stone Arch Bridge.
At 6:05 p.m. everyone bowed in silence to remember the moment the bridge collapsed a year ago. Then a police inspector read the names of each victim. A dove was released after each name was read.
A construction crew then unfurled the American flag on the west side of the replacement bridge, facing the Stone Arch Bridge.
Victims’ families boarded a river boat and, escorted by Sheriff’s deputies, scattered flowers and wreaths into the Mississippi River. An eagle, not part of the program, circled above the crowd during the ceremony.
Bridge is 90 percent complete
Construction crews finished paving all eight lanes of the highway leading to and from the new bridge on both sides of the Mississippi River. This week they are paving ramps, shoulders, curbs and gutters along the main highway; pouring concrete on Span 4 of the bridge deck; and preparing the area between Abutment 5 and the Second Street Bridge to be poured.
Other construction activities during the week of August 4 are installing signal poles and fences along the ramp at Washington Avenue, installing lighting and anti-icing equipment along the highway to and from the bridge, and building barriers, rails and curbs on the sides of the bridge’s main span.
In addition, crews will excavate a holding pond south of the river, seed and sod the holding pond on the north side of the river, and begin to restore the area on West River Parkway.
Peter Sanderson, bridge project manager, said the bridge is 90 percent complete. Of the estimated 670,000 hours needed to work on the bridge, less than 90,000 hours of work remain, including administrative work that will continue after the bridge opens to traffic, he said.