SPARROWS POINT, Md. (WAVY) – WAVY News was invited to tour the new Midtown Tunnel Element Fabrication Facility in Maryland Thursday.
Erin Kelly was up in Sparrows Point on a tour with the Elizabeth River Tunnels Project Team. There, the group learned how the tunnel elements are being made and how they’ll make the journey down the Chesapeake Bay to Hampton Roads.
The tunnel tube will be placed parallel with the existing tube. This will create two additional lanes of travel for motorists crossing the Elizabeth River at the Midtown Tunnel.
According to Elizabeth River Tunnels, the new tube will consist of 11 concrete tubes, called elements. The elements are being built in a dry dock. Once complete, a tug fleet will tow the elements 220 miles to the project site in Portsmouth.
Project Engineer Daniel Francis explained the timeline for construction.
“We have the first six elements of 11 elements that we have to cast to build this tunnel,” he said. “We will be floating these elements out here in June, and we’ll be casting another five of those as we finish these up, so these will float out and then we will start casting operations again, working right in the same dock, building another five elements.”
The nearly completed sections weigh 16,000 tons each, but they’ll have to be buoyant to get to the Elizabeth River, where they will be lowered to about 100 feet below the water’s surface and into a trench. Crews have to make each section work like vessel for transport, Francis said.
“These elements have temporary walls. That will allow the elements to actually float,” he said. “They’ll float about three feet above the water, and actually we’ll tow them down. And then we’ll actually add water inside of them to allow them to be heavy enough to immerse under water.”
Project Director Wade Watson said the tunnel will include a new safety feature for drivers in need of an escape hatch.
“It’s a separate corridor outside the roadway behind concrete walls and there’s doors about every 350 feet, so if an incident occurred in the tunnel, a motorist could leave his car, walk into a doorway that’s within 350 feet, exit into a portal behind the concrete wall,” he said.
Engineers said there is enough waterproof coating on the tunnel to cover six football fields, and enough concrete that you could build a sidewalk from the facility outside Baltimore to Portsmouth.
The tunnel project costs $1.5 billion and is expected to be finished by December 2016, according to project leaders.