Northeastern’s Boston campus is about to be transformed. It will happen literally overnight.

Years of planning, investments, and a bold vision to reimagine Columbus Avenue in Boston will realize its next step when two spans of bridge, totaling 200 feet and 168 tons, are erected across the Amtrak and MBTA railroad tracks this weekend.

Early Saturday morning, as soon as the last orange line train has passed between the Ruggles and Massachusetts Avenue MBTA stations, electricity for the tracks will be shut off for as long as four hours. One of the largest cranes on the Eastern seaboard will lift the first span of bridge, 64 feet long, and thread its 47 tons into its place within the densely-occupied campus on the north side of the tracks.

And then, in the early hours Sunday, while the city is asleep, a similar action will be performed with greater weight and delicacy. This time the fire-engine-red Manitowoc MLC-650 crawler crane, which is 189 feet tall, will hoist another section of bridge that is twice as large as the first. The tension and urgency of this event will be underscored by the slow, cautionary path of the structure, 132 feet in length and 242,000 pounds, as it is raised, moved, and then lowered to its assigned location between the Interdisciplinary Science and Engineering Complex and the Ruggles Station.

The bridge will serve as a means of access to many destinations. In addition to furthering the university’s long-term plan to unify the campus, the state-of-the-art passageway will also link two neighborhoods that are home to the Boston campus.

Ralph Martin, Northeastern’s general counsel, said the new span expresses “an open university, where we invite people to travel in and across our campus.”

“What the bridge will do is bring two different communities together: the Roxbury side and the Fenway side,” he said.

The fusion of the Huntington Avenue side of the campus with the more recently-developed installations to the south was jump-started by Joseph E. Aoun. Not long after he became Northeastern’s seventh president in 2006 Aoun moved his office to Columbus Avenue.

“The challenge of having railroad tracks run through the middle of the campus is considerable,” said Kathy Spiegelman, vice president and chief of campus planning and development at Northeastern. “The addition of the bridge over the tracks, and the landscape that leads up to it from Columbus Avenue, is a corroborating part of identifying the fact that the campus is engaged with that part of the city.”

The new bridge extends Northeastern’s vision to reimagine Columbus Avenue. The development of International Village and the Interdisciplinary Science and Engineering Complex were followed in August by the reopening of the Carter Playground as a state-of-the-art recreational park, refurbished and maintained by the university at a cost of $108 million. Two months later comes the dramatic construction of a visually stunning bridge that promises to become a landmark for the 120-year-old university.

A vision of bridge-building

The assembly this weekend of the main pieces of the as-yet-unnamed bridge will be enhanced by further construction and landscaping, in order to be integrated with the communities it is meant to serve. The bridge is projected to be open for pedestrian traffic in 2019.

While the project will appear to have been framed in a matter of hours this weekend, the commitment to its design and construction began two years ago.

“It really is an art piece,” said Northeastern program director Cassandra McKenzie, who is directing the bridge project. “This is a statement from our university to the city of Boston to say we are on board for beautification, we are committed to art, we are committed to making these grand statements.”

After the two spans have been coupled on Sunday by Skanska, the Swedish-based construction firm hired by Northeastern, its crews will begin work on adding the upright steel fins as tall as 18 feet that will serve as the walls to the bridge. As pedestrians make their way across the structure, gaps between the fins will fan open incrementally to reveal views of the Boston skyline.

“They will open to only one side,” McKenzie said. “We want you to look at the city of Boston.

“Every fin has a different angle. When you start, you can’t see much. But then as you start crossing the railroad tracks, they open up a little more, a little more, so you can see the city. It will totally open up to you, and it will be a fascinating view.”

There could have been less aesthetic solutions to the construction of a bridge over the tracks. Within the narrow confines of the campus, the designers at the Payette architectural firm came up with a way of telling a story of Northeastern’s role as a unifier within the Boston community.

“People will have a safe and beautiful path to come through our campus and up to the Frederick Law Olmsted Emerald Necklace, which is a magnificent, beautiful resource,” said Spiegelman. “Alone, the bridge isn’t going to unite the neighborhoods and the university.”

But with International Village, Carter Playground, and other developments, a coherent message is being sent.

“People can start to say that Columbus Avenue is joining Northeastern,” said Spiegelman.

A means to experiential learning

Sammy Alshawabkeh, a graduate student in civil engineering, began a co-op last month with Skanska, just five weeks before the weighty events that will happen this weekend. He has spent that time working with Skanska project manager Andrew Pramberger, who at age 31 has worked on a variety of projects, including the creation of New York’s Second Avenue Subway. This is his first bridge.

Pramberger has taken it upon himself to be on top of the hundreds of crucial details that must merge without incident, like traffic on a rush-hour freeway, for this ambitious vision to be consummated. The crane had been located, moved to Boston piecemeal, and assembled on site upon a specially-constructed platform that would prevent it from sinking into the earth. There have been soil samples and weather forecasts and interstate delivery schedules. The Boston Red Sox will have a playoff game on Saturday night, and will it end in time for the tracks to be shut off?

At a final planning session Tuesday, Pramberger presided over discussions with managers of the project that included the eventual placement of emergency call boxes, handrails, an elevator shaft, and whether the upcoming parents’ weekend and homecoming celebrations will affect plans going forward. Throughout this project there has been a need to coordinate with the MBTA, which has been renovating the Ruggles Station while Northeastern has been transforming the neighboring parking lot on Columbus Avenue into a landing site for the new bridge.

“We struggled a lot in the beginning with getting everybody on the same page and really focusing that effort,” Pramberger said.

As they have worked through the details that have grown ever more immediate and urgent, Pramberger has been consistently receptive to the co-op’s questions. This has surprised Alshawabkeh. But it is understandable, in the same way that police detectives prefer to talk over the details of an investigation again and again, to make sure that nothing has been missed. It is a way of managing the tension, of making the unknowns seem familiar.

“You can definitely see that they’re excited,” Alshawabkeh said of the crews that have been on site. “They’re not a grumpy bunch. They’re usually pretty happy, and pretty cooperative.”

Alshawabkeh, who is the son of Akram Alshawabkeh, the George A. Snell Professor of Engineering at Northeastern, is experiencing teamwork as it should be. Workers from a variety of specialties are realizing how much they need each other, on behalf of this larger goal to unify by extension and to fulfill potential by way of a visionary dream. This is how bridges are built, indeed.

Tune in to watch it live

During the second stage of the installation, on Sunday, October 14 from 12:01 to 1:30 a.m., Northeastern will host a “Midnight Master Class,” including a lecture and expert interviews that will explain the details of the construction, to be followed by a live viewing of the bridge installation. Both the Midnight Master Class and the live construction will be streamed via Facebook Live from 12:01 a.m. to 4:00 a.m. at facebook.com/northeastern