Gantry Cranes Help to Solve Engineering Problems On I-481 Bridge Construction in Syracuse, N.Y.

Mon March 10, 2025
Syracuse Post-Standard & NYSDOT

Interstate 481 over the CSX rail yard in DeWitt, N.Y., just outside Syracuse, is being widened as part of the ongoing $2.25 billion I-81 viaduct project.

The $384.5 million design-build contract focuses on constructing the southern interchange of Business Loop 81 and I-81, modifying the new I-81 interchange with New York Highways 5/92 in DeWitt, and expanding the corridor between I-690 and Kirkville Road.

As part of the effort, a pair of gantry cranes have been dispatched to the work site to carry steel beams into place between existing bridges on the freeway.

The bright yellow machines have caused plenty of motorists to slow down to gawk at the three-story tall structures. In fact, they are so big they had to be assembled on site, the Post-Standard reported March 10, 2025.

For the uninitiated, gantry cranes can usually be found working at rail and shipping yards, where they can lift a shipping container.

But their use on the I-481 project is all about providing an engineering solution to a tricky construction dilemma.

Picture two existing 2,100-ft.-long bridges side-by-side over a functioning railroad. The northbound and southbound bridges are separate structures with a little space in between.

Contractors with CNY Alliance, a joint venture made up of three construction firms based in the state, are working on the design-build project. With the gantry cranes, they are adding one lane to each side of the bridge structures, as well as building new lanes in the middle space, the Syracuse news source noted.

As a result, there is not much room to maneuver construction equipment between the two bridges, said Jim Harmon, the engineer in charge for the New York State Department of Transportation (NYSDOT).

Enter the gantry cranes, each with wheels taller than a human being.

The two cranes will roll over the lanes with one wheel on each existing bridge. In their giant hooks, the Post-Standard said, they will carry the heavy steel beams needed to support 15 spans of new bridge deck.

"It's very tight down in the middle where the cranes would have to sit to set the beams, so these [machines] carry the load differently than a traditional crane," Harmon said.

Over the next six or eight months, he added, the cranes will roll back and forth with 60 beams, each one weighing 68,000 lbs., roughly the weight of 19 Subaru Outback cars.

It took approximately a week for workers to haul in the crane parts and build them on site, according to Harmon, and several more days for operators to learn how to run the cranes in this unusual configuration, he said.

One critical advantage to using the gantry cranes at this specific site on the I-481 project is that the machines can walk the beams into place above the bridges without touching the fragile wetlands or the railroad lines below.

The idea to use the gantry cranes in this manner came from CNY Alliance, which is responsible for this particular section of the project, said TeNesha Murphy, a NYSDOT spokesperson.

The companies making up the joint venture are the Rifenburg Companies, in Troy, N.Y.; A. Servidone/B. Anthony Construction, located in Castleton; and Cortland-based Economy Paving Company Inc.

The work is part of the massive effort to tear down the elevated Interstate 81 in downtown Syracuse and build up I-481 to handle more high-speed traffic around the east side of the city.

Drivers will continue to have a close-up view of the DeWitt work for at least the next two years until that portion of the overall I-81 rebuild is completed. In the meantime, traffic will continue to flow on two lanes north and south during the construction, according to NYSDOT.

This story also appears on Construction Equipment Guide.