Die Frau Floats!
An innovative German-made Demag CC1800 hydraulic crane was floated by steel-erection subcontractor Abate-Irwin to help build the longest curved girder bridge in Pennsylvania.
The crane was equipped with a 200-foot boom and a 88,200-pound, suspended "superlift" counterweight, giving it a rated lift capacity of 186 tons at a 30-foot radius.
Trumbull Corporation of Pittsburgh was awarded the $17.3 million prime contract for the Ford City Bridge on State Route 128 over the Allegheny River, forty miles north of Pittsburgh. The contract called for replacement of an outdated, two-lane, through-truss bridge by a modern, continuous plate girder bridge. A total of 44 prefabricated sections were field-spliced to make up the 1060-foot continuous plate girders of the three-span bridge. Of these sections, 28 had to be set from river.
Robishaw Engineering designed a 6,800 square-foot Flexifloat Series S-70 spud barge to support the 614,000-pound Demag crane working on the river. The "T"-shaped barge assembly was comprised of 12 Quadrafloats and 10 Duofloats and utilized 24-inch diameter Spuds and Spudwells for positioning and anchoring. The barge was designed to draft only 3.5 feet and to trim less than 2 degrees while the crane lifted and set 150-foot girder sections weighing 149,000 pounds at a 65-foot load radius to heights of 65 feet above the river.