Demolition work is to commence shortly for the remains of the Francis Scott Key bridge link in the US. The demolition of the existing structures of the Francis Scott Key Bridge is expected to begin on or about July 7, weather permitting, according to the Maryland Transportation Authority (MDTA). This will be a major stage for the bridge replacement project. Demolition and removal of the central portion of the bridge that had been blocking the channel was removed by Skanska.
The bridge collapsed in March 2024 when it was struck by a container vessel that had lost power. Although warnings from the vessel’s crew meant traffic could be stopped, six construction workers on the bridge at the time were unable to escape and were killed. Opened in 1977, the bridge had recently passed inspections at the time of the disastrous collapse but did not feature protection around its supports that more modern structures would now feature. The channel leads to a busy port and vessel sizes have increased considerably since the bridge first opened.
Carrying I-695, the bridge carried 11 million vehicles/year. Replacing the structure will help cut congestion around the Baltimore area, with traffic delays having increased considerably since the bridge collapse.
The demolition work is expected to take several months to complete and will involve carefully dismantling the remaining portions of the Key Bridge. The process will begin with removal of bridge deck over the river, followed by demolition of sections over Hawkins Point and then Sollers Point. This phase of work focuses on removing portions of the existing structure that interfere with the alignment of the new bridge. Controlled blasting will not be used during this phase of demolition.
The work will start with the removal of deck, barriers and parapets over the river from both Hawkins Point and Sollers Point. This will be followed by the removal of deck, barriers, parapets, girders and piers on the landside approaches, down to just below ground level, from both Hawkins Point and Sollers Point. The original north and south abutments will then be removed.
MTDA says that the work will require active tug and barge operations on the river, with heavy equipment and trucks using the remainder of the bridge structure. Barges will serve as protective shielding during demolition and must be avoided by waterway users.
The machinery used will include excavators, concrete saws, vacuums, cranes and trucks. An on-site concrete crusher will recycle materials for haul roads and staging areas, reducing truck trips and cost. Buoys will mark a safety zone, no entry area around active work areas.
Based on months of field investigations and engineering analysis, the bridge alignment is down-river of the original structure, remaining within MDTA’s existing right-of way. The new bridge will feature substantial protection measures around its supports to prevent collapse in the event of being struck by a large vessel.
To proceed with construction, the MDTA is requesting modifications to permits that have been issued by the Maryland Board of Public Works, Maryland Department of the Environment, US Army Corps of Engineers and the US Coast Guard in support of the Key Bridge Rebuild. The permit modification requests will reflect updates to bridge pier foundation design and pier protection elements, adjusted trestle configuration and a decrease in impacts to tidal waters, with some additional impacts to non-tidal wetlands and waterways.
A reevaluation of the project’s Categorical Exclusion will also be submitted to the Federal Highway Administration. No significant increase in environmental impacts is expected.
Visible activity will increase on the Patapsco River this summer. Schedules are still being refined, but MDTA will provide advanced public notice two weeks before major activities begin.
Mobilisation of marine equipment, the pile test frame and driving of test pile is scheduled to begin this summer and continue through the fall. Drilling and sampling will continue this summer both on the land and water to support detailed design.
Construction of the new cable-stayed bridge is expected to cost up to $1.9 billion. Measuring around 3.2km in total, the new bridge providing a safer crossing for drivers than the earlier structure spanning the Patapsco River.
A joint venture comprising STV and Michael Baker International will provide construction management and inspection services to Kiewit and Bridging Maryland Partnership, which is a joint venture of RK&K, JMT and WSP for the design-build project. The central span of the new bridge will be wider at 305m compared to the 213.4m of the collapsed structure. The bridge clearance will be 70m instead of the previous 56m.
