By John Kuka
Engineered Rigging’s unique Cantilever Segmental Bridge Lift helped speed construction of the new 6,236-foot Cline Avenue Bridge in East Chicago, Indiana. The bridge straddles the Indiana Harbor and Ship Canal, a critical commercial shipping lane. Blocking this vital shipping passage with a massive construction crane traditionally used in bridge replacements was out of the question. Engineered Rigging’s new lift system enabled crews to move 19 concrete bridge segments, each weighing 75 tons, in just 16 days — all while keeping a commercial waterway open.
Prior to its closure in 2009, the Cline Avenue Bridge was a popular route for 35,000 vehicles a day. Located less than 10 miles from the Indiana-Illinois border, the bridge will be heavily used by the significant interstate truck traffic traveling on nearby I-90, I-80 and I-94.
“We were able to leverage our knowledge of strand jacks, skidding and tensioning to design and build a safe, economical lifting solution that also allowed commercial cargo vessels to continue using the canal,” explained Engineered Rigging President, Christopher Cox, P.E.
Strand Jacks Perform the Heavy Lifting
The Cantilever Segmental Bridge Lift features four strand jacks, each with a lifting capacity of 17 to 1,405 tons. The strand jacks act like linear winches. Each features a bundle of steel cables or strands that are guided through a hydraulic cylinder. Above and below the cylinder are anchor systems with wedges that grip the strand bundle. By stroking the cylinder in and out while the grips are engaged in the anchors, a lifting or lowering movement is achieved. Diesel or electric hydraulic packs supply the power. Used together, the strand jacks allow for precise, synchronous lifting. Engineered Rigging can simultaneously operate up to 60 strand jacks via computerized controls to lift very large loads.
“Because of their compact footprint, strand jacks are ideal for use at construction sites — such as the Cline Avenue Bridge — that cannot accommodate a crane,” explained Cox. “In addition, a single operator can remotely control the strand jacks, which improves safety on site,” he added.
Floating Barge Positions Bridge Segments
Engineered Rigging’s Cantilever Segmental Bridge Lift attached to the bridge’s edge and extended horizontally over the water, with strands hanging below the platform. Crews then positioned each 75-ton concrete segment on a small barge below the lift.
This cantilevered design enabled Engineered Rigging to lift each span thus enabling crews to secure it in place over the waterway. Once secured, Engineered Rigging repositioned the Cantilever Segmental Bridge Lift to the newly installed span so that the next concrete section could be hoisted into position.
The configuration for this project supported a lifting speed of 60 feet per hour. “Once positioned, it took only 2 hours to lift a single segment” said Cox.
Skid Track Slides Lift into Position
After each lift, Engineered Rigging’s onsite team had to reposition the system. It used specially designed half pieces of skid track, which matched the geometry of the bridge. This approach enabled the track to go down without delay. The team then used a split flow pump to operate the skidding system, which moved the Cantilever Segmental Bridge Lift into position for the next lift.
The split flow pump also powered the side shift hydraulic cylinders used to position the concrete span side to side when aligning with previously installed segment. The pump also operated the main long stroke cylinders, which pushed the platform out on the cantilever beams and pulled the segment into place longitudinally after it was lifted and buttered with epoxy. All of the systems were critical to aligning the new bridge span along the X and Y axes and used in conjunction with strand jacks in the Z axis.
“The hydraulic cylinders and split flow pump enabled us to easily orient the bridge segments so that we could lock them into place with post tensioning equipment,” Cox explained.
Engineered Rigging’s team faced several unique challenges when designing, fabricating and operating the lift. First, the engineers had to factor in Mother Nature. Autumn weather along the shores of Lake Michigan can be extremely windy and cold.
“We designed system to work in temperatures below freezing and in winds that matched the capability of the crane onsite,” explained Cox. “This weatherproofing allowed us to meet our schedule of installing at least one segment per day.”
To reduce costs, the customer asked that Engineered Rigging use the steel beams that it had already purchased to construct the lift. To accommodate that request, Engineered Rigging carefully inventoried and accurately modeled the materials on hand. The lift’s design comprised approximately 50 percent existing material and 50 percent new.
Using the existing beam inventory caused additional issues. The Cantilever Segmental Bridge Lift needed to weigh less than 75,000 lbs., otherwise the pier and cantilevered segments would not be able to support it during erection.
“Some of the existing beams were oversized and added unnecessary dead weight,” noted Cox. “To solve this issue, we optimized all new fabrications to minimize weight and counter the heavier, oversized components.”
Custom Design and Fabrication
Engineered Rigging provided engineering design, fabrication, heavy lifting equipment rentals and onsite technical support for this complex project. It spent 12 weeks designing and fabricating the Cantilever Segmental Bridge Lift at its facility in Arkansas. Its team worked hand in hand on-site personnel during the planning and engineering phases.
“Once onsite, that cooperation continued,” said Cox. “We worked very closely with the bridge developers, construction teams and contractors during execution of the project. We were especially cognitive of safety, as that’s of paramount importance whenever lifting anything so massive.”
The company’s engineers and equipment technicians were onsite at the bridge for about a month, which included set-up and teardown of the lift system. Active lifting took approximately 16 days. The bridge opened on December 23, 2020.
“Working on the Cline Avenue Bridge allowed us to apply our specialized lift expertise to a project that will have a significant, positive impact on the economic development of Northwest Indiana,” added Cox. “The new bridge will be a lifeline to nearby Chicago and beyond for commercial and industrial businesses along Indiana’s Lake Michigan shoreline.”
The Cantilever Segmental Bridge Lift system can be customized for bridge projects of any size in North and South America. In addition, Engineered Rigging has an array of heavy lifting equipment available for rental and sale, including the powerful and compact strand jacks. For more information, visit www.EngineeredRigging.com.
John Kuka is Director of Business Development at Engineered Rigging.