By: Roads & Bridges
A project was undertaken just north of Niagara Falls, N.Y., to replace the existing surface of the Lewiston-Queenston Bridge. It is a four-lane divided structure between the U.S. and Canada with a pedestrian sidewalk. Its span stretches 1,600 ft between abutments and hovers 370 ft above the Niagara River. In 2004, it was decided to replace the existing surface with a fifth lane by eliminating the pedestrian access route and middle barrier wall.
Since this bridge is a link across the border between Canada and the U.S., an international effort was joined between Rankin Construction in Canada and Oak Grove in the U.S.
They would both begin at the center of the bridge, signifying the border between the nations. It was imperative that the bridge remain balanced, so each would remove the slabs, working toward their respective riverbanks.
Oak Grove had been using the Kenco Slab Crab for about 10 years. According to Bob Spengler, Oak Grove superintendent, “The Slab Crab is safer and much less labor-intensive than other methods of removing slabs.” Based on their suggestions, Rankin purchased a Slab Crab to use for this project.
First, the 7-in.-thick concrete was saw-cut into pieces of about 6 ft by 10 ft. The teeth of the Slab Crab were slipped under the slab and the bond was broken. Each piece was secured and lifted onto a waiting truck. By using this technique, the cooperative effort was accomplished in just eight days.
