Construction crews are beginning to drive massive cylindrical piles into the Patapsco River bottom, part of the next stage of the expedited rebuilding of Baltimore's fallen Francis Scott Key Bridge.
If everything goes right, some of the steel piles could later form part of the new Key Bridge, engineers said; primarily, though, the recent piles are merely test subjects.
Once they are positioned deep within the riverbed, workers will top them with a large yellow cap that functions as a hammer, striking the pile repeatedly to test its strength. Eventually, the blows will reach a maximum force of approximately 10 million lbs., according to Brian Wolfe, the director of project development at the Maryland Transportation Authority (MDTA).
"We know the piles can carry the load, just based on steel being a known material. What's unknown is that river bottom," Wolfe explained in speaking with Maryland Matters. "This is to verify how far down … we need to drive those piles … in order to get the load that we need to carry the bridge."
During a sampling effort in the Patapsco, engineers discovered that the first 60-70 ft. of the riverbed is "soupy," he said. In other words, it is much too soft to support an enormous cable-stayed bridge.
But beneath all of that muck is an "extremely hard" layer, Wolfe added, and the piles will need to burrow deep into that layer in order to hold up the bridge.
Each pile is more than 200 ft. long, 8 ft. in diameter and weighs approximately 340,000 lbs. Therefore, maneuvering them requires some of the East Coast's largest cranes, as have several other parts of the complex effort to demolish the old bridge and bring in the new.
Six piles have already been placed in the Patapsco River, and crews are busy cutting excess rusted steel from the top of each piece, leaving behind sections that have been coated to prevent water intrusion and degradation, said Jason Stolicny, MDTA's deputy director of project development.
Following that, a steel frame will be placed on the piles as they are carefully monitored during testing to see how they withstand the hammer blows.
As work continues with the piles, crews will employ a technology called a "bubble curtain" to soften underwater noise from the hammer blows, which minimizes impacts to fish and other animals in the river, the MDTA said. Using air compressors on a barge at the site, crews create Jacuzzi-like bubbles around the piles, capable of dampening sound waves.
Several weeks' worth of data from the hammer blows will determine whether the new bridge's foundation is strong, and construction can proceed apace, Wolfe said. So far, he indicated the pile installation has gone as planned and matches the contractor's expectations about the sediment at the bottom of the river.
"It's essentially confirming what we had anticipated from the boring program," he said. "[The piles] went through that soupy material right to that hard layer like we had anticipated."
On March 26, 2024, a cargo ship bound for Sri Lanka, carrying more than 4,600 shipping containers, struck one of the bridge's support columns after a mechanical failure on the ship, sending the structure careening into the water and killing six construction workers who had been working on the roadway above.
Still, reminders of the terrifying crash more than a year and a half ago remain on the site, including a large concrete pier, now surrounded by barges, cranes and construction equipment.
MDTA, Kiewit Working at ‘Breakneck Speed' to Build Bridge
Even though work is under way on the new bridge, which has a target completion date of fall 2028, crews are still removing large pieces of the old one. That demolition work is roughly halfway complete, according to engineers, and is expected to continue through early 2026.
Currently, crews are focused on removing the remaining bridge spans that run over the land. Stolicny said they hope to erect a temporary access trestle that will allow workers to easily reach the bridge site on the river.
Initial projections placed the cost for the bridge replacement at $1.8 billion, with a 2028 reopening date.
However, MDTA Chief Engineer Jim Harkness was less than certain about the completion date and told Maryland Matters that his team is still working with its contractors to determine the project schedule and estimate.
The agency's target for opening the new bridge is still the fall of 2028, he explained, adding that MDTA is moving at "breakneck speed" to get the structure built.
An official groundbreaking is likely in the next few months, Harkness added, who noted that the new bridge will have rigid fenders to protect its piers from potential ship strikes.
Nebraska-based Kiewit Corp. is approximately 70 percent finished in its design of the new cable-stayed bridge, with a projected completion date at the end of November. Engineers began working on the plans in September 2024.
"We're expecting to have 2,000 plan sheets make up the design for this bridge. If you printed all that out, you'd have a stack of paper nearly 8 inches tall," he said. "Something that would normally take a team years, we've been able to accomplish in 14 months."
One potential hurdle that has cropped up in recent months is the federal government, which pledged during the last months of the Biden administration to fully fund a Key Bridge replacement. President Donald Trump has hinted that his administration may not decide to do so, although Maryland leaders note that the funding agreement was written into law.
"We will continue to work with the Trump Administration to find ways to reduce costs and rebuild faster," Maryland Gov. Wes Moore said in a statement. "We anticipate the price estimation process to be finalized in the coming months and we will provide regular updates."
