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NTSB’s findings on bridge collapse have political consequences

WASHINGTON, D.C. — The National Transportation Safety Board (NTSB) released its preliminary findings today (PDF) on the likely cause of the I-35W bridge collapse, and the report has some immediate political consequences.

WASHINGTON, D.C. — The National Transportation Safety Board (NTSB) released its preliminary findings today (PDF) on the likely cause of the I-35W bridge collapse, and the report has some immediate political consequences.

The likely culprits in the Aug. 1 collapse were faulty steel plates that held together the bridge’s beams, the NTSB said. A final report won’t be finished until this fall, but the indication that it was a design flaw (PDF), not bad upkeep, has political implications. If the bridge was poorly designed, not poorly maintained, some pressure comes off of Gov. Tim Pawlenty’s administration to account for the collapse. That, in turn, could take the air out of renewed DFL efforts to raise the gas tax during this year’s legislative session.

Some DFLers have tied the bridge collapse to Pawlenty’s veto of a transportation and gas-tax bill last year. But the governor said today that the report helps separate transportation funding from the bridge issue.

“It shifts the debate where it should be, which is: have that debate about those needs, do it in a respectful, factual manner, and quit exploiting the bridge tragedy to advance their political agenda,” Pawlenty said.

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“I would hope people would at least have the decency to correct their statements,” he said of those who said his veto helped bring down the bridge.

‘Serious design error’
NTSB Chairman Mark Rosenker told reporters that gusset plates about the size of a small sidewalk square may have been too thin to keep the bridge together. The plates near where the bridge first broke apart were half an inch thick, half the thickness of some other plates. Sixteen of the half-inch plates, at eight spots on the bridge, broke apart, while all others remained relatively intact.

Rosenker called the plate thickness a “serious design error,” but said the original calculations used in designing the bridge, which opened in 1967, could not be found. “We cannot determine whether the error was a calculation error, a drafting error or some other error in the design process,” he said.

“What caused the failure is yet to be determined,” Rosenker said, noting carefully that the plates show how the bridge fell, but may not fully explain why. Repairs in 1977 and 1998 had thickened its concrete bed by 2 inches, to 8.5 inches, and the bridge was being repaved when it collapsed. The final report will reveal what Rosenker called “the straw that broke the camel’s back.”

DFLers suggested that bad maintenance still could be a culprit if poorly maintained expansion joints led to increased pressure on the gusset plates.

Minneapolis Mayor R.T. Rybak, a DFLer, issued a statement today saying the bridge collapse “was not an act of God, but a failure of Man. Our state and country have not invested as we must in roads, bridges and transit — and that lack of investment has serious consequences.”

Bridge cost $400 million
The news comes on the heels of Pawlenty’s Monday announcement of a $965 million public works bond package, with $225 million of that amount dedicated to bridge repair statewide.

The DFL says the state ought to raise the gas tax, not more bond debt, for road repairs. Last year, DFLers pushed through a 5-cent increase in the 20-cent-per gallon gas tax that Pawlenty ultimately vetoed. Now that DFL Rep. Jim Oberstar chairs the U.S. House Transportation Committee, he has argued that Minnesota stands to reap a federal transportation spending windfall if the state could pony up dollars for the feds to match.

The gas tax generates more than $600 million a year for Minnesota, of which about $135 million gets matched by federal dollars, according to congressional sources. An increase would raise the amount that Congress could match.

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In December, Congress included $195 million in emergency funding for the I-35W bridge repair in its year-end spending package, bringing total federal funding to $373 million.

Pawlenty said the bridge would ultimately cost about $400 million, and predicted it would be open by the end of the year. Construction of the fallen bridge took about three years to complete.

The $225 million in bonds would be designed to replace about 600 bridges, about a third of the reported 1,800 deficient bridges in Minnesota.

The news also comes atop the release of a report today calling for a federal gas tax boost of up to 40 cents per gallon. Given rising gas prices — already a presidential campaign issue — and increasing talk of recession, an attempt to boost the tax this year at any level will be politically challenging, to say the least.