Portal North Bridge: Behind the delivery of three bridge arches down the Hudson River

On an average day, more than 300,000 people travel by train across New Jersey’s Portal North Bridge, many of them commuting to and from New York City. That kind of use is hard on public infrastructure, and our team is now replacing the 115-year-old bridge with a new modern version.

Currently, Skanska is building 2.5 miles of double track, including a 3,660-foot-long approach span located on the west side of the Hackensack River, a 2,540-foot-long approach span on the east side, and a 1,200-foot-long center span crossing directly over the river.

Once complete, the modernized transit route will have a huge impact on the local New Jersey community, as well as the greater Metro New York region. Improved reliability and operating speeds will increase the number of trains per day that cross the bridge.

A focus on safety and efficiency during this milestone moment

For our team to successfully deliver three 400-foot-long, 500-million-pound bridge arches down the Hudson River, they had to develop a plan that was both safe and efficient, which led them to Upstate New York.

Our team preassembled the network-tied arch bridges in Albany at the Port of Coeymans—a decision made early in the planning process. Assembling the arches at Coeymans would save time, money and improve safety.

Throughout assembly, our team installed 60 cable hangers per arch, and each cable hanger consisted of 31 strands of cable. They utilized an innovative approach in conjunction with VSL to preassemble the cable anchor heads, which eliminated the need to pick and set each strand at the anchor in the arch segments.

Our team optimized the construction schedule and access to each of the arches by incorporating the electricians and carpenters in the prefabrication process, which saved time and reduced exposures to hazards. They installed the sidewalk brackets on the bridge during prefabrication, laying the foundation for formwork and concrete placement.

“We ran the electrical through each of the arches, so every bit of the electrical systems were installed at Coeymans, which reduced exposures on the river,” explained Laszlo Borhi, project executive.

Once the arches were prefabricated, our team used Mammoet's heavy lift equipment to drive them up onto barges so they could be floated down the Hudson and Hackensack Rivers. It took about 30 hours for one arch span to reach our site because they had to navigate under 18 different moveable and fixed bridges along the way.

After each arch arrived onsite—typically in the middle of the night to not disturb daytime commuters—our team would bring it through the existing Portal Bridge before jacking it 60-feet-high into place and onto the piers.

“I would equate the process to a dance because everything was heavily planned and coordinated ahead of time, especially with the weather we experienced during the arch float ins,” said Michelle Miyaki, superintendent II.

The first arch float took place in November 2024, the second occurred in January 2025 and the final arch float took place in February 2025. Having to navigate freezing winter temperatures as well as wind coming off the river was unavoidable.

“The Coast Guard had to use an ice breaker to break up the ice down the river before we could start the voyage. When we were jacking, the wind also had to be below 15 or 20 MPH, so we were constantly keeping an eye on the weather three to four days in advance,” explained Michelle.

Even while dealing with tough weather conditions, erecting the arches upstate and floating them down the Hudson River as opposed to building them onsite proved beneficial in several ways.

“In addition to it being more affordable from a labor perspective, building the arches on land versus over water is much safer. There are so many safety hazards that come with working over water at height,” said Michelle.

“It also took less time to build them upstate because if we were to build them onsite, we would have been essentially stick building the arches over the river,” she continued.

Lessons learned throughout the process

Our project team learned several lessons from their experience floating the first arch that they applied to the following two arch floats to improve the process.

“For the first arch, we worked around the clock to complete that milestone. We realized that for the second and third arches, we could be just as efficient working staggered shifts,” explained Michelle.

This was particularly true for the jacking process.

“During the jacking process of the second and third arches, we added more chain falls to help erect the bracing. Seeing space is always limited on barges, so we had to configure two of the sides with manual 5-ton chain falls. For the other two sides that had more space, we used a telehandler to assist with installing the jacking elements. As our team started learning the system, we became faster at it,” said Michelle.

“The first time we jacked, it took two 12-hour shifts—by the second and third arches, we were able to complete the entire jacking process in 14 hours,” she continued.

Now that our team has completed these three major arch floats, they are looking ahead to the next major milestone for Portal North Bridge, which will involve moving the existing trains over onto the new tracks.