March 11, 2008

Boston crews reinforce Longfellow Bridge’s deteriorating beams

BOSTON

The Red Line thunders overhead as construction workers perched on a platform repair the gritty underbelly of the Longfellow Bridge, using bolts and clamps, cutting torches, and steel to patch the worn bridge piece by piece.

Their job is not to reconstruct the bridge — that massive task comes later, at a much greater cost — but to shore up beams so deteriorated they are no longer reliable. The shiny new stretch of metal they installed overhead relieves a crusted and corroded beam of its load, a story in the Boston Globe reports.

It might as well be a big steel Band-Aid.

“We’re doing the repairs to make the bridge last until we can get the major rehabilitation,” said Dave Lenhardt, supervisor of parkways and bridges for the Department of Conservation and Recreation (DCR), which manages the Longfellow Bridge.

“It’s about 10 years overdue for a major rehabilitation,” he added. “We didn’t have the money.”

They still don’t.

The long-postponed restoration of the Longfellow is at least three years away, while state officials, shaken by the collapse of an interstate bridge in Minneapolis last summer, inspect and bolster the bridge with interim fixes.

Officials are certain that the Longfellow will not collapse; it has hundreds of redundant steel segments that would shoulder the bridge’s load if one should falter. But just in case, they have been under the bridge since August, all night, most nights, checking the structure and duplicating weak sections with new steel supports.

The 100-year bridge carries 49,500 vehicles, 84,000 Red Line passengers, and countless pedestrians and bicyclists each day. They don’t need a degree in civil engineering to know the bridge needs help. The steel arch ribs are coated with rust. The concrete curbs are crumbled in spots. And the elaborate granite towers that give the bridge its “salt and pepper” nickname look sooty and worn, more pepper than salt. The Longfellow has only had two major overhauls — in 1959 and 2002.

“It’s a shame when they don’t do these things,” said Catherine Despujols of Somerville, who takes the Red Line over the bridge. “The ironwork is gorgeous.”

On a frigid Wednesday night, contractors Dave Miller and the aptly named Toby Bridges worked on the bridge, cutting steel to bolt on to a weakened post. Each segment must be custom-cut to fit. It is slow and tedious work that cannot be done any faster. And the Longfellow has 100,000 steel components like it.

The main problem with the Longfellow is the water and road salt seeping through longitudinal joints and corroding the steel below. Those joints are like seams that run the 1,700-foot length of the bridge along the MBTA’s train tracks that will need to be removed to plug the leaks.

“That’s why water’s still leaking,” Lenhardt said.

When the restoration begins, the state wants to keep the Red Line running. The ambitious Longfellow restoration is now expected to cost US$200 million. Comparably, the Longfellow cost US$249 million — in today’s dollars — to build a century ago, according to a report issued by the Pioneer Institute last summer.

DCR hopes to pay for some of the reconstruction with money from the governor’s proposed transportation bond bill, which includes US$250 million for Charles River Basin bridges. But that bill needs legislative approval.

“Again, that’s not enough to pay for everything. But it is the first time any governor’s administration has identified a significant amount of money to make repairs to structures,” said DCR Commissioner Richard K. Sullivan Jr.

Since the Minneapolis bridge collapse in August, the state has stepped up oversight of the Longfellow, spending up to US$4 million to repair problems identified in a 40-day inspection; DCR has not released the consultant’s report, saying it is not yet final, though it is making repairs based on the report.

DCN News Services

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