The Connecticut River Bridge, built in 1907, is being replaced to improve reliability and reduce delays for trains and maritime traffic. The $1.3 billion project will feature a new two-track electrified bridge with modern infrastructure, expected to be completed by summer 2030. Funding from FRA, Amtrak and Connecticut.
O&G Industries photo
Constructed in 1907, the Connecticut River Bridge connects the towns of Old Saybrook and Old Lyme.
Constructed in 1907, the Connecticut River Bridge connects the towns of Old Saybrook and Old Lyme. In summer 2024, the O&G/Tutor Perini Joint Venture team broke ground on the new Connecticut River Bridge, which is expected to be completed in summer 2030.
Amtrak notes that more than 60 Northeast Regional and Acela trains, CTrail Shore Line East commuter service trains and freight trains cross the 117-year-old 1,600-ft. bridge daily. While the wood-supported bridge is serviceable, it's at the end of its useful life.
"The new bridge will enhance reliability, resiliency and reduce delays for all users of the bridge, according to Amtrak. "It is designed to support a maximum operating speed of 70 mph, a 55 percent increase from the current maximum speed of 45 mph. Maritime navigation and safety will also improve due to the increased vertical clearance compared to the existing bridge."
There's significant maritime activity on the Connecticut River, where the bridge is located (in southern Connecticut). The bascule bridge opens more than 2,800 times annually to allow boats to pass. The Connecticut River Bridge occasionally fails to open and close as designed, resulting in delays for Amtrak and maritime traffic.
"The amount of routine maintenance that Amtrak puts into keeping current bridge functioning is substantial given its age,' said Peter Spath Jr., senior project manager of O&G Industries. Spath is overseeing the Amtrak project.
The new Connecticut River Bridge will sit 52 ft. south of the existing bridge (centerline to centerline). The move was necessary to give the construction team space to work and not impact the current bridge.
The two-track bridge, projected to have a 100-year useful life, will be electrified and movable. It'll feature "a trunnion bascule span design with modern track, signal, catenary, power, communication and other supporting rail infrastructure."
As Spath and the team focus on building the new bridge, they have one eye on the old one.
"One of my biggest concerns is that the old bridge continues to function as intended during construction of the new bridge," he said.
The bridge was built on wood piles, granite piers and abutments.
While the age/stage of the bridge is a reason for concern, the more pressing concern is that the construction activities of the new bridge don't impact the old bridge.
"Construction activities on the new bridge have the potential to impact existing structures," Spath said. "We will be continuously monitoring the existing bridge's substructure, superstructure and tracks to ensure the structure doesn't move outside of tolerance."
Should this occur, the team would pause construction of the new bridge, evaluate the old bridge, and take any necessary actions to ensure the old bridge is secure.
The design team, including the consulting engineers, was aware of the sensitivity of the existing bridge. They considered this issue while evaluating the existing conditions and determining where to place the new bridge. Ultimately, the decision to put the new bridge south of the current one was best for both bridges.
The team has been (and will continue to be) engaged in prep/site work before construction. When teams work on water, they typically must engage in environmental tasks depending upon the aquatic and plant life.
"We had environmental requirements that we needed to attend to right out of the gate in order to maintain the schedule," Spath said.
The team had to treat phragmites and relocate endangered plant species. A delay in handling the environmental requirement would have put them eight months behind until the next planting season.
Getting equipment to and from the site and creating a work area also is part of the prep work. The O&G/Tutor Perini Joint Venture is leasing land near the bridge. The staging/laydown area will be used for temporary storage of materials and subsequent loading onto barges materials and equipment to be used in constructing the new bridge. Six of the nine approach spans also will be pre-assembled there, and moved onto barges to be floated into place, saving both time and costs.
Many of the craft also will access the water work from this location. The team also is building a temporary trestle on the east and west sides of the river for access to the approach land-based work, south of the existing bridge, as the river's edges can only be accessed from the north side of the existing tracks.
The team plans on fabricating a 204-ft.-long steel truss Bascule span off site. Upon completion, they're going to float it into its final position via barge and heavy lift equipment. As mentioned earlier, six of the approach spans also will be floated in place, however three of the spans are being stick-built in place. Spath said this is because the water is either too shallow restricting barge access for floating a preassembled span into place, or there are conflicting structures like the new control house and rear fender system.
It was decided that construction should occur on the south side of the project. The decision means the existing control house on the south side of the bridge must be relocated to the north side. The existing electrical infrastructure, such as submarine cables and the infrastructure signal, also are being relocated to the north side.
The team also is engaged in road work associated with the railroad approaches. The railroad bed must be realigned with the new bridge, which requires new retaining walls and the earthwork associated with these approaches, involving cofferdams, piles and or rock anchors and cast-in-place retaining walls and backfill.
Spath described some of the key work that needs to take place before.
"We have to drill six-foot and eight-foot diameter steel casings into the bedrock to support the east and west abutments, piers and bascule and resting piers. This and the concrete work for the east and west approaches are critical for the new bridge and will require us to monitor the old bridge."
The team is engaged in geotechnical investigations to check the quality of rock, sediment, and mudline to get a level of detail required for the installation of the foundations for the new bridge. The team also is doing additional boring and probes on the perimeter and landside.
The O&G and Tutor Perini team have a long history of partnership. Their first project was the Baldwin Bridge, just north of the Connecticut River Bridge. The team constructed the four-lane, 2,500-plus-ft.-long bridge 30 years ago. Over this time, the two companies have joint-ventured on 11 projects totaling more than $5 billion across numerous states. In addition to two ongoing projects in California and this Amtrak project, the team recently was selected as the Contractor for the Newark AirTrain Replacement Project.
The joint venture and its management team also have worked with Amtrak on multiple occasions.
"The people overseeing this project and the owner's rep are a great group of people to work with," Spath said. "They are always willing to come to the table and get through issues for the benefit of the project."
The $1.3 billion project is receiving funding from the Federal Railroad Administration (FRA), Amtrak, and the State of Connecticut. CEG
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