The hydraulic jacks that will be used to straighten and adjust the Liberty Bridge's fire-damaged structure are in place, the bridge project's contractor said Thursday. Crews planned to test the equipment before they start the actual jacking process. Jim Wilkinson, executive vice president at West Deer-based Joseph B. Fay Co., described the process in a written statement as “very methodical” and said it could take multiple days. PennDOT officials in a written statement said crews will use “lateral and longitudinal” jacks to rotate and realign a damaged joint on the bridge's truss. Once the joint is realigned, the longitudinal jacks will lengthen and straighten a damaged chord, “which will redistribute the bridge loads back to their pre-fire loading conditions.” The jacks will require a minimum of 2 million pounds of force to move the bridge between 1 and 2 inches in slow increments of about an eighth of an inch while engineers read gauges attached to the structure and monitor whether the repair requires adjustments. The bridge has been closed since a fire Sept. 2 damaged 30 feet of a crucial compression chord while Fay crews worked on an $80 million, multi-year bridge rehabilitation project.
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