Mackinac Bridge Painting Project Earns Engineering Award
At the Structural Engineers Association of Illinois 2019 Excellence in Structural Engineering Annual Awards, Ruby+Associates took home the Best Neighboring State Project Award for the bridge painting platforms.
"As this is the first time in the bridge's history when the towers have been stripped to bare metal and repainted, it makes sense that Ruby+Associates, Moran Iron Works and Seaway Painting would need new, innovative equipment to get the job done," said Mackinac Bridge Authority Executive Secretary Kim Nowack. "We congratulate them on the award and thank them for their work preserving this infrastructure icon."
The platforms were custom designed and built for Seaway Painting crews to enclose and move up and down the bridge's towers above the roadway deck, first during the 2017-2018 project to strip and repaint the bridge's north tower, then again during the current 2019-2020 project to do the same on the south tower. The platforms encircled the tower legs and allowed workers to adjust it to accommodate the tower tapering near the top. Another platform allowed access to the struts joining the tower legs.
The award nomination noted that the design needed to withstand winds regularly exceeding 100 mph and allow for the enclosure and capture of paint and sandblasting materials. The original paint is lead-based, and Seaway is required to contain 100 percent of the paint as it is removed and ship it to an appropriate landfill facility. The new paint, which is zinc-based, is expected to last at least 35 years, with periodic maintenance.
The south tower contract is for just less than $6.5 million, with Seaway required to complete the project by December 31, 2020. The contract to repaint the north tower was just less than $6.3 million. Installation and removal of the platforms has required brief closures during the overnight and early morning hours on several occasions.