HRCP photo
The article below originally appeared in and is posted with permission from:
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Before choosing Hills Machinery to supply it with the Hitachi machines, HRCP did its due diligence and, in the end, the decision to go with Hills and Hitachi came down not just to cost, but quality.
Crews began onsite work more than four years ago to build the largest highway construction project in Virginia's history. When they are finished, the result promises to have a major effect on vehicle traffic in the populous and often-congested Tidewater area of the state.
In 2019, in an effort to increase capacity, ease major congestion and enhance travel time reliability, construction started on the $3.9 billion expansion of the 3.5-mi.-long Hampton Roads Bridge-Tunnel (HRBT).
To reach the project's goals, a team of U.S. and European contractors are collaborating to widen the current four-lane segments along almost 10 mi. of the Interstate 64 corridor in Norfolk and Hampton and dig new twin tunnels to create eight lanes across Hampton Roads, one of the world's largest natural harbors where three major rivers, including the James, come together just west of the mouth of Chesapeake Bay.
The massive job is being done on behalf of the Virginia Department of Transportation (VDOT) by Hampton Roads Connector Partners (HRCP), an international construction joint venture that includes Dragados USA, a subsidiary of its Spanish parent company, two France-based firms — Vinci Construction Grands Projects, and Dodin Campenon Bernard — and Flatiron Constructors, headquartered in Colorado, one of the U.S.'s top infrastructure contractors.
A second joint venture of engineers and designers is also working on the effort, made up of HDR Inc., a worldwide engineering firm based in Omaha, Neb., and Mott MacDonald, a company headquartered in the United Kingdom.
In addition to the new tunnel construction, the HBRT project will replace five bridge structures, widen another 20, build new marine trestles, and install a drivable shoulder lane in each direction between Norfolk and Hampton.
Although originally projected to be completed in late 2025, VDOT said that delays have pushed the bridge-tunnel expansion to either 2026 or 2027.
Gigantic Tunnel Boring Machine Hard at Work
The state transportation agency entered into a design-build contract with HRCP four years ago to expand the I-64 tunnel, which first opened in 1957 as an immersed tube connecting two human-made islands and linking Hampton, on the north shore, to Norfolk on the south, via trestle bridges.
The new project is expanding the I-64 HRBT by adding a new pair of two-lane tunnels, each 8,000 ft. in length, which will link the existing North and South islands — also being broadened to handle the new lanes — with trestle bridges off the shores of Hampton and Norfolk.
The tunnels are currently being carved under the seabed with a 46-ft. diameter tunnel boring machine (TBM), according to the construction joint venture. The 430-ft.-long, 4,700-ton behemoth is powered by up to 16 electric motors, with its main drive delivering over 7,500 hp. Depending on soil conditions, the project's builders noted, it is expected to mine up to 50 ft. per day.
"The TBM actually bores and places segment linings as it goes," said Megan Pym, project manager of the construction's joint venture and an employee of Flatiron. "As it progresses, because of the soil present, the TBM also injects a slurry mix into the ground to help strengthen the tunnel before we come in with our crews to build the roadways and the walls."
The 21,492 segment linings slated to be placed in the tunnels are cast in Cape Charles, Va., on the eastern shore of the bay, and are sent to the project site by barge.
As it moves along, the TBM will reach a depth of 101 ft. under the seabed — channel depth is 72 ft.
The scale of the Hampton Roads Bridge-Tunnel expansion project is so immense that even a veteran construction professional like Pym is in awe of its size.
"Not only is it quite large due to the size of the contract, but it is also impressive when you consider the scope of the work," she described from her office near the work site. "At least for me, the scale of it is unlike anything I have ever seen before, and we are all proud to be a part of it."
Work Under Way to Finish South Island Expansion
Pym's team was given the critical task of enlarging the artificial islands where the I-64 roadway enters into and emerges out of the I-64 tunnel.
Their initial work began on the North Island near Hampton, she noted, by building 14 acres onto the existing structure, a job completed in 2022. To do so, the construction team brought in thousands of tons of rock, most of it on floating barges, and used Hitachi excavators to lift and place the material in the water to increase the island's volume.
Starting in spring 2024, they began building the South Island off the Norfolk coast, a smaller structure encompassing only 3 acres, but one that is much more complex than the one to the north, Pym said.
"That is because it is scheduled to take almost double the amount of time due to unique challenges that involve not only the tunnel construction but also bridge structures all coming together in one small area," she said.
It was from the South Island that the TBM started its work in 2023 while slowly heading for the North Island, where Pym said a receiving pit was built to meet the machine. Once the boring machine arrives, crews rotate it on a turntable and drive it back to the south to complete the tunneling process. The project's slurry treatment plant is also found on the South Island.
A unique set of challenges were put in front of Pym's team as they planned their work on expanding the artificial islands in the middle of Hampton Roads.
The most critical was fitting the needed construction equipment into a tight working space while also being extremely cautious about keeping her crew safe as they worked just feet away from the live I-64 traffic driving past on a temporary bridge. Another was putting safeguards in place to make sure the work could be performed without harm to people and machines on the water, where unpredictable winds and currents can become a hazard.
"All those normal construction challenges seem to be magnified because we are also working next to the tunneling team, which is bringing in slurry barges, and transporting the segment linings to the site," according to Pym. "We have an entire marine logistics group that sits next door to help us coordinate all these barge moves, and equipment transports on the water, and there is a second group that does the same for the land work as well."
If that were not enough for her team to keep in mind, Pym noted that the existing tunnel's medium electric voltage line runs through the area where her team works, "so our Hitachi operators have to work very carefully."
Hitachi, Hills Machinery Dependable Project Partners
The one thing Pym does not have to worry about is the reliability of the Hitachi excavators that HRCP acquired from Hills Machinery, the Charleston, S.C.-based equipment dealer well known in four Southern states, including Virginia.
In fact, the construction team's decision to use the highly maneuverable and rugged Hitachi 890LC-6 and 1200-7B to expand each island has proven to be an inspired choice, she added, due to the tight quarters within which their operators must work.
"These machines work well here because of the unique nature of the area where we have the road traffic, the tunnel, and its approaches to the north of us, plus the new bridge structures coming in. That means we need this specialty equipment in order to place rock from a very confined space. They are very large pieces of equipment, yet these excavators give us more maneuverability," she said.
Before choosing Hills Machinery to supply it with the Hitachi machines, HRCP did its due diligence and spoke to other dealers, but Pym said that in the end, the decision to go with Hills and Hitachi came down not just to cost, but quality.
"Our superintendent has had some experience with Hitachi overseas, so he was on board with it, and Scott McDougle and his team at Hills provided maintenance service and warranty agreements, which are especially important in marine work," she said. "The conditions here are very tough on construction equipment with the ever-present salt water. If you don't have the right setup or the proper maintenance, these machines will break down."
The assistance provided by McDougle and Hills Machinery to the contractors extended beyond finding the right machines for the project, Pym said, as the dealership also helped spec what booms, buckets and grapples were required to help prevent the excavators from knocking into passing vehicles or the site's permanent structures.
"Just because of the uniqueness of the arm and the size of the material we are working with, when you get into construction like this there are not a lot of standard parts and pieces that you can use, so the right specialty attachments are extremely important. That's why working with Hills Machinery is great because in looking at what we were building and how we were doing it, they helped make sure we had the attachments that fit our needs."
Hills Machinery also assembled the large Hitachi 1200, which has an operating weight of approximately 264,600 lbs. when equipped with a bucket.
"They did a great portion of assembling this machine at our pre-cast yard," Pym said. "I was a little scared about seeing it in person, but when I finally did, I found it to be amazing. Seeing the Hitachi 890 is impressive too, but when I saw the 1200, that was a ‘wow' moment for me because I am tall, but there is a chunk of the boom on that machine that is taller than me."
Hitachi Excavator Models Perfect for Job
The construction team's 760-hp. Hitachi 1200 excavator does its job from a barge and transloads its rock by swinging it toward the Hitachi 890, which will then be used to place the final shape, she said.
"We are moving rocks that make up three different sizes," Pym added. "For example, the largest rock has a medium weight of 6.5 tons, and the range goes all the way down to our small rock, which is our 3-inch to 9-inch stone, so the excavators not only had to carry the large capacity rock but the smaller ones as well."
To do so, the Hitachi excavators each use separate attachments, she added, just as each rock size is handled by specific attachments.
To increase the size of the existing South Island, its rock layers are built on either side of a coffer dam. The Hitachi excavators are working close to a series of permanent and temporary bridge bents, Pym said, "so we have to place rock all around because the piles will be in place as well as some of the cap beams."
With the seabed reaching a varied but maximum depth of about 30 ft. where the contractors are working to build the island, the Hitachi 1200 was outfitted with a special long-reach boom so it could not only reach across its barge, but also swing over a coffer dam and set the rock in order for the Hitachi 890, sitting on the rock platform it built, to place the rock in its final position.
"And to add another unique challenge, most of it is done underwater, so folks don't even get to see the beautiful and complex work the Hitachi machines are doing," Pym said. "But survey equipment aboard the Hitachi helps us see the rock placement in a 3D view."
By using the efficient Hitachi excavators, she anticipates the South Island expansion part of the overall project to be finished in 2025.
HRBT One of Two Tunnel Expansions in Tidewater
The Hampton Roads Bridge-Tunnel is the fourth bored roadway tunnel project in the United States, along with similar ones in Seattle and Miami. In addition, just a few miles east of the HRBT, an expansion is currently underway on the Parallel Thimble Shoal Tunnel between two human-made islands, part of the enlargement of the Chesapeake Bay Bridge-Tunnel that connects Virginia Beach to the Eastern Shore of Virginia.
Each of the Tidewater tunnel projects are needed to keep up with the ever-growing traffic concerns in southeast Virginia. The busy region encompasses seven cities with populations exceeding 90,000 residents, including Virginia Beach, Norfolk, Chesapeake, Newport News, Hampton, Portsmouth and Suffolk.
Besides being a top tourist destination, with beaches and historic sites nearby — like Williamsburg, Jamestown, and Yorktown — the area is also home to the largest U.S. Navy base in the world, and one of the Atlantic Coast's top commercial shipping ports. CEG
