Francis Scott Key Bridge Rebuild Plans Minor Course Change

Maryland transportation officials have proposed altering the route of Baltimore’s new Francis Scott Key Bridge in an effort to accelerate construction and limit environmental impacts.

Originally planned to occupy the Patapsco River footprint of the original 1.7-mile steel bridge, which collapsed after being struck by a disabled container vessel in the early morning hours of March 26, 2024, the new two-mile-long cable-stayed structure will be built on a parallel alignment approximately 260 ft to the southeast.

According to the Maryland Transportation Authority, the move allows work on the new structure to ramp up while demolition of the old bridge’s remaining portions proceeds, removing a potential obstacle from meeting the currently scheduled fall 2028 completion date. Along with avoiding leftover debris from the collapsed structure, the agency hopes to minimize the disruptive effects of dredging the old bridge’s remaining piers from below the mud line, which could have downstream water quality effects on the Chesapeake Bay.

Because the proposed rerouting plan involves a change to the project’s environmental permit, it must be approved by the Maryland Dept. of the Environment, and the state’s Board of Public Works. MDTA has not said how long that process will take. Since getting underway in July, demolition work on the old bridge has focused first on removing remaining bridge sections extending into the Patapsco River. Once that work is complete, workers will remove the remaining ground level sections, followed by the abutments.

Designed by Kiewit Infrastructure Co. under the $73-million first phase of a progressive design-build contract, the new bridge will be longer and higher than its 1970s-era steel arch continuous truss predecessor, providing greater vertical and horizontal clearance to accommodate the increasingly large vessels calling on the Port of Baltimore. The design calls for the two 600-ft-tall main span pylons to be separated by more than 1,600 ft, with the bridge deck 230 ft above an approximately 1,000-ft-wide main deep-draft shipping channel.

The new pylons also will have a collision protection system in line with AASHTO-recommended standards for bridges of this type.

The National Transportation Safety Board, which continues to investigate the collapse that killed six construction workers, noted a March 18, 2025 vulnerability guidance document that the four 28-ft-diameter, rubber-fendered dolphins constructed along the old Key Bridge’s 700-ft-wide navigation channel were insufficient in both size and location to protect the structure’s piers from a collision from an off-course vessel.

Meanwhile, test piles are expected to be driven into the Patapsco River’s soft riverbed next month. The total cost for the replacement bridge has been estimated at $1.7 billion, though MDTA says it plans to issue a revised cost and schedule this fall.

The post "Francis Scott Key Bridge Rebuild Plans Minor Course Change" appeared first on Consulting-Specifying Engineer