July 2020
Safety and technology lead installation of BNSF bridge segments over I-294
WESTERN SPRINGS, IL – Interstate 294, also known as the Central Tri-State Tollway, runs through the western portion of Chicago’s massive metro area. It is a major arterial expressway—averaging 220,000 vehicles per day--connecting people and goods to some of the region’s most important commercial and residential nodes. In Western Springs, Illinois, I-294 is crossed by the Burlington Northern Santa Fe (BNSF) Railroad via a three-track bridge. The BNSF is not only the largest network of railroad freight in the United States but also the owner of the railway used by Chicago’s busiest commuter rail line, the Metra BNSF.
This pulsating junction is the site of Walsh Construction’s BNSF Bridge Replacement project, a three-year undertaking, at the direction of the Illinois Tollway, to not only increase the number of tracks from three to four but to lengthen the bridge to accommodate planned upgrades to I-294 below. The conundrum for the project team: how to safely carry out these essential infrastructure improvements with the least possible disruption to the flow of people and goods that rely on unobstructed passage?
The team found the answer by using advanced construction technology techniques. Rather than rely on a lengthy schedule to construct a temporary bypass, or build the bridge in place, segments would instead be assembled in nearby staging areas and moved into place by Mammoet's self-propelled modular transporter (SPMT). An SPMT is multi-axle platform vehicle with precision, computer-controlled operation. Each axle of the SPMT is controlled independently, allowing the segments to placed with pinpoint accuracy. Crews will then be able to remove and replace the existing bridge without disruption to train traffic.
“Steel Erection can be very dangerous work especially working around live traffic at night,” said Project Manager Brian Keller. “To have the ability to reduce that risk by building the bridges off the roadway, implementing safer MOT configurations, and using a different technology to erect the girders in a shorter span of time is a huge benefit to the employees, traveling public, and our company. The exceptional teamwork put into the intensive planning of this operation and our commitment to safety provided the path to a successful SPMT bridge erection.”
Phil Griffith, Operations Manager at Walsh Construction appreciates the capabilities of the SPMT technology and it’s ability to help benefit the project schedule. “All six sets of girders were installed over I-294 in a matter of hours overnight [in a single weekend]. The heaviest segment was approximately 467,000 pounds and had only inches to spare,” he said.
The safety implications of this methodology are huge, as crews were able to effectively build the shoofly bridge during the day and away from traffic at the staging areas, rather than depend on overnight construction and numerous commuter impacts.
“The original plan was to build the bridge in place over I-294 and would have required many nightly lane closures,” said Nick Everson, Program Manager at Walsh overseeing the project. “The method of moving preassembled segments into place required only a few closures; reducing impacts to the traveling public and reducing risks to the trade workers.”
The BNSF Railway Bridge Project is being coordinated with Metra, BNSF Railway and Cook County, along with local municipalities, park districts, as well as police and fire departments. The railway bridge is one part of the Illinois Tollway’s 15-year, $14 billion capital program, Move Illinois: The Illinois Tollway Driving the Future.
“This was a tremendous team effort, Area Equipment and Mammoet brought first class expertise and professionalism; and we are grateful to the Illinois Tollway for the opportunity to deliver this critical piece of infrastructure in a safe manner while reducing impacts to the Tollway users,” added Griffith.
The BNSF Bridge Replacement is scheduled for completion in 2022.