Remaining Key Bridge structures will be blasted, demolished to make way for new span

Hayes Gardner, The Baltimore Sun
·3 min read
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BALTIMORE — The container ship Dali is gone. So, too, is the bulk of the 50,000 tons of wreckage that tumbled into the Patapsco River when the Francis Scott Key Bridge collapsed on March 26.

Some of the last vestiges of the Key Bridge and its demise are the two existing ramps — which led to the bridge’s main span — still standing in the water. They, too, will be gone soon as authorities make way for a rebuilt Key Bridge by October 2028.

The Maryland Transportation Authority’s request for proposals (RFP) for the new bridge states that it “desires to remove the existing portions of bridge structure still standing as early as practicable, permittable, and approvable.”

Those portions cannot be reused as part of the new bridge, a transportation authority spokesperson said.

Parts of those bridge ramps, as well as the “dolphins” — artificial islands, 25-feet in diameter, designed 50 years ago to serve as bumpers protecting the felled span from ship strikes — will be destroyed via mechanical demolition and explosives, according to two letters from the transportation authority to the Maryland Department of the Environment.

Some of the process, which will take about 10 months, won’t be dissimilar from work done by crews to clean up the shipping channel in the months after the bridge collapse. The bridge deck that still stands over the water, for example, will be “cut into manageable pieces, lifted by crane onto trucks and transported for disposal,” according to a May 31 letter from transportation authority Director of Project Development Brian Wolfe.

Portions of the existing bridge over land will be “dropped to the ground and removed,” the letter stated.

Substructure and piers will be mechanically broken apart or blasted — at which point pieces would be recovered from the river bottom, per the letter. Those portions then would be transported by barges out of the river.

Destroying three of the remaining piers will require “three separate blast events,” according to a June 7 letter from Julie McCarthy, the transportation authority’s natural resources lead.

The June 7 letter specified that removing the bridge’s parapet walls and deck will be done so “mechanically.” However, the removal of land spans and land piers, as well as the remaining water piers and “dolphins” would require explosives, at least partially.

For the dolphins, portions above the water will be “mechanically demolished” while those submerged in the water will be destroyed with explosives. The debris will be removed later from the river bottom with excavators and a clamshell dredge.

It won’t be the first time the Key Bridge recovery has required explosives. The 984-foot Dali, which lost power and crashed into a Key Bridge support, killing six men, was stuck in the Patapsco River for nearly two months. Authorities used explosives to cut up a large piece of bridge that sat on the ship’s bow, which later allowed the vessel to be pulled and pushed to the Port of Baltimore by tugboats.

Destroying the ramps could have environmental impacts, from affecting water quality to introducing pollutants. It also could decrease the ability of fish to pass through the water because of the increased noise and the movement of equipment. But the transportation authority said any environmental impacts will be temporary and that it will “limit impact to water quality to the greatest extent practicable.”

The demolition is scheduled to begin this summer or fall and take roughly 10 months. During that time, however, efforts to build the new span will be ongoing.

The transportation authority will select the builder of the new Key Bridge by the end of this summer and the span will be constructed using a “progressive design-build” — an expedited process that allows the chosen team to build as it continues planning. The bridge is expected to cost roughly $1.7 billion and be, at least primarily, federally funded.

The Maryland Department of the Environment will host a public informational hearing regarding the demolition project Aug. 1 from 4:30 to 7:30 p.m. at the Baltimore County Public Library, North Point Branch.

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