Logo

Lifting Gear Hire

Bristol, PA 19007

5.0

Company Info

  • Est. 1990
  • Size 100-249 Employees

Featured Project Return to Projects List

Rehabilitating the Congress Parkway

Project Information

Project Location:
Chicago, IL
Status:
Completed - May 2015
Structure Type:
Bridge

Scope Of Work

THE SITUATION

Rehabilitating and reconstructing a 60 year old bridge can sound pretty daunting, especially if it hasn’t experienced significant repairs since its creation. And that’s exactly what Walsh Construction had to do for the Congress Parkway Bascule Bridge in Chicago, IL.

 

The bridge was constructed in the 1950s as part of the national highway development. It had received minor repairs since then, but no major overhauls had ever been conducted. Due to its poor state, in 2010, the Illinois Department of Transportation reached out to Collins Engineering and two subcontractors – Delgado Construction and Walsh Construction – to rehabilitate the four structural steel bascule leafs of the eastbound and westbound bridges.

 

Included in the repairs was a complete replacement of the decking system and the components that open the leafs, which included ensuring the leafs remained balanced, so they may properly open and close controllably.

 

THE CHALLENGE

In reconstructing an aged conduit, Walsh had to lift 112’ bridge leafs, lock them in at a 70 degree angle, and then lower them back down in a controlled slow manner. Walsh’s Project Manager, Joe Q., said there were additional challenges that presented themselves during the course of the two-year project.

 

“The real challenge was keeping traffic open,” Joe explained, “while trying to do the rehabilitation because the eastbound and westbound bridge would have traffic on one set of bridges while we worked on the other. During the construction, we had to maintain boat traffic. During the summer, sailboats passed through twice a week – Wednesdays and Saturdays – we had to ensure that the bridges could be lifted upwards to allow the boats to cross. Keeping the bridge balanced proved challenging, too. Every time we put a piece of steel onto the bridge, the piece of 10 pound steel that was 100 feet away from the pivot arm acted the same as a 1000 pound piece of steel that was 10 feet away from the pivot arm on the back side. So, all these little things because of the nature of the project became exasperated and had to be taken into account and reviewed.”

 

Aside from a few unexpected issues, all bascule bridges in Chicago have two long trusses that have floor beams that run transverse along the road and grating that goes from floor beam to floor beam. So, pieces of the open grated decking have deteriorated over time, which only made replacing the steel that much more challenging.

 

THE SOLUTION

To rehabilitate the bridge, Walsh installed an Orthotropic Deck System. While it’s still a structural steel system which consists of two truss arms and floor beams, the steel is of a lighter weight and the floor beams are smaller, so the weight is transferred into the decking system itself. ½ inch flat metal plates and steel webbings underneath give it its structural support. Being a closed system, it’s not exposed to deterioration and doesn’t allow salt or chemicals to fall into the river or down the structural steel and makes for a more maintainable bridge.

 

During boat session, in order to let the boats pass, Walsh raised three out of the four bridge leafs, locked them in an upwards position while they continued to rehabilitate the bridge as it hung 220 ft in the air. Using a scaffolding system and a crane, Walsh replaced the steel piece by piece.

 

During the winter months, Walsh jacked the leafs the opposite way to where it could not lift upwards.  The 500 ton jacks were used to lift the bridge leafs up a quarter of an inch, so all the weight would go into the temporary support system whereby they could do all the repairs that could not be done while in the up position.

 

To complete the task, through (the former) Delgado Erectors, Walsh contacted Lifting Gear Hire to figure out what equipment might be needed for the project. The initial idea was to try and find a winch that could pull the bridge down at a slow and controlled manner, in consideration of the teeter tauter effect, that the bascule bridge functionally operates. It was Walsh’s desire to either co-op or buy a winch that LGH did not offer for rental during that time. LGH informed Walsh that the winch in question was extremely slow in speed (7ft per minute) and recommended something better that they could rent instead. The winch they ultimately chose was faster but achieved the slower desired speeds by multi-parting the line through some double sheaved blocks. In addition, because they now were using this mechanical advantage, they would not require as large of capacity winch as was initially sought.

 

Walsh rented and employed the use of two air-powered winches (Thern, TA7-24) by attaching them to a barge on the Chicago River 150’ below the tip of the bridge. Additionally, they used four high tonnage double-sheaved blocks (Shookum, 20-ton WLL, 14” diameter) and telemetry crane scales (supplied by AWS Load and Torque Load Systems) that monitored the forces.

 

“When we got most of the rehabilitation done,” Joe continued, “we lowered the bridge using the air winches at a controlled measure and finished the project with them down. It was a constant struggle to keep the bridge balanced in order to properly open and close the leafs. We went through a lot of different sized jacks. Different kinds, different apparatuses, different setups, when the team (Lifting Gear Hire) eagerly jumped in and provided not just what we were asking for but other items that were available that could make the job easier.” 

Share URL copied!
https://www.thebluebook.com/iProView/1551342/lifting-gear-hire/material-suppliers/
Facebook
LinkedIn
Request Brochure

We will send a link to your email address that will download our FREE PDF brochure.