BALTIMORE, Md. — It only took a few seconds for the ship to take down the Key Bridge, and now it'll only take a few seconds to remove the steel truss resting on its deck. "Precision pressure charges," a type of explosive, will do the job.
The Unified Command says this is an industry-standard practice, and is the safest and fastest way to get that piece of the bridge off the Dali.
The steel is under a "tremendous amount of pressure and tension," meaning, if crews themselves were to make the final cuts, the steel could bounce back like a spring.
As for the safety of the crew on board the ship, Darrell Wilson, a spokesperson for the Dali's owner says one option that was discussed was for the crew to remain on board in a designated safety area, adding the company will take guidance from the experts at Unified Command. Wilson also said the crew "will eventually be allowed off the ship," but they're currently busy with normal duties as well as assisting with response efforts.
Unified Command provided us with an animation, demonstrating how the demo will work.
This narrated animation video shows how the controlled demolition is going to work, and what it will look like. @WMAR2News pic.twitter.com/VeTYZeLaXY
— Elizabeth Worthington (@ElizWorthNews) May 8, 2024
"This highly controlled process enables surgical precision. It consists of 4 steps," the narrator in the video says.
The first two steps are already done. Engineers analyzed the steel, strategically marking where to make cuts. Then, using diamond saws and torches, operators cut into the steel.
They're now on the third step, described by the narrator: "Third, the charges are placed within the cuts, and then encased with a wrap similar to a large piece of tape."
Unified Command says demo crews are 40-50% done with that process.
"Finally, the charges are initiated and the steel is separated by precision cuts that are merely millimeters in width. Upon execution, the steel structure will be thrust away from the Dali," the narrator explains.
The Army Corps of Engineers provides further details: "Because of the pressure charge’s high velocity upon detonation, the copper casing of the shaped charge is briefly turned into a plasma jet that will literally cut through critical portions of the remaining iron truss. The detonation sequence is timed so the pieces will fall into the water for later retrieval by salvors, and in a manner that’s unlikely to cause additional damage to the M/V Dali. After the pressure cutting is complete, the Unified Command will inspect the vessel and re-survey the riverbed for wreckage, so the M/V Dali can ultimately be re-floated and moved out of the federal channel."
Barring any delays, the controlled demolition is expected to take place this Sunday. The Unified Command hopes to provide us with a safe spot on the water to observe, so we can bring you images of that demolition.
