Mammoet Helps Install Pittsburgh Bridge in Under 24 Hours

By Simon West

Mammoet played a central role in replacing one of Pittsburgh’s busiest bridges in less than 24 hours, using a specialist skidding system to slide a new 10,000-ton span into position after the old structure was demolished.

The operation formed part of the replacement of the Commercial Street Bridge, which carries more than 100,000 vehicles a day. The new bridge was assembled alongside the existing crossing over several months before being moved 102 feet sideways into its final position in a single continuous shift.

“We moved the entire bridge structure whole — the deck and the main support structures,” said Mark Lane, engineering team lead at Mammoet. “Our skidding system allowed for this type of solution to be feasible and provided the quickest means of replacing the bridge.”

The project used accelerated bridge construction (ABC) techniques, reducing traffic disruption from what Mammoet said could have been nearly four years of intermittent lane closures under conventional construction methods to a 17-day continuous closure. The existing bridge remained open until shortly before the replacement operation began.

Mammoet used 42 hydraulic skid shoes across four support points to move the entire bridge, including its deck and main support structure, while maintaining alignment within a one-inch tolerance. Engineers carried out a five-foot test slide before completing the final installation.

The original concrete bridge, built between 1948 and 1951, had undergone three rehabilitation programs before being replaced to accommodate modern permit loads.

According to Mammoet, the project marks the heaviest bridge it has moved in the U.S. using its specialist skidding system, which was previously used in 2016 during the installation of the New Safe Confinement structure at Ukraine’s Chernobyl nuclear site.

Mammoet will be exhibiting at Breakbulk Americas 2027.