It was going to take a special crane to handle the project to replace the isolated Wildwood Bridge located in Hampton Township, Pennsylvania, near Pittsburgh. How about one that could perform both the demo of the old bridge and assist with construction of the new one? ALL Crane Rental of Pennsylvania, a member of the ALL Family of Companies, had just the tool for the job: a 330-ton capacity Manitowoc MLC300 crawler crane equipped with VPC-MAX.
VPC-MAX is Manitowoc’s Variable Position Counterweight® proprietary technology to actively engage all counterweights and eliminate the need for passive carbody weights. The design results in a dramatically reduced transport configuration and better center of gravity for reduced ground bearing pressures.
Because of the railroad tracks and a mine water treatment facility right in the lift zone, there was only a small strip of land where the crane would fit.
“The lifting capacities enabled with VPC-MAX are unique for the MLC300’s size,” said Mark Damich, sales representative with ALL Crane Rental of Pennsylvania. “It lets the counterweight cantilever and move as it picks heavy loads. With that ability, the MLC300 in this configuration can lift with cranes in the 660-ton class, but with a smaller footprint that was ideal for this job, being in a confined space. For its size, it was still able to perform the heavier lifts well within safe capacity.”
The project, from ALL customer Mekis Construction, involved replacing the existing superstructure of the five-span bridge carrying State Route 4070 (Wildwood Road) over Willow Run, railroad tracks, a mine treatment facility, and a private drive. Work included new hammerhead pier caps, abutments, a concrete bridge deck, approach slabs, and a bridge barrier.
First came demolition of the old bridge, which took about a month. The MLC300 was first used to lift off the old beams and bridge deck, with the bridge deck portion left on top of the beams as they were lifted out. The heaviest piece lifted was a 350,000-pound pier cap approximately 50 feet across.
Due to the isolated location, delivery of the crane was a consideration as well. Because the MLC300 with VPC-MAX packs a powerful punch in a smaller package, it could be delivered in about half the truckloads of a higher-capacity crane.
“Mekis has a sizable lay down yard next to the site. We were able to build the crane there then walk it just 250 feet to its final set up,” said Damich. “Configured with 217 feet of main boom, the crane is able to work from one spot, as required by the site confines.”Where the old bridge used precast adjacent box beams, the new structure is made of steel girders. The same MLC300 has remained on the job site to set four of the five spans, ranging in weight from 37,000 pounds to 85,000 pounds. When its work is complete, the unit will have been at the job site for three months.