Allentown arena starts to get its roof overhead

A milestone of sorts for Allentown's new arena has begun.

Three massive cranes this morning began lifting the seven 236-foot-long roof supports, called trusses, into place above the 8,500-seat PPL Center. Workers hoisted 85 feet in the air in high-reach cherry-pickers will use pneumatic wrenches to fasten the trusses into place with massive bolts.

Each truss, a curved structural support laced with a series of steel triangles, weighs between 125,000 and 212,000 pounds.

The first truss is expected to take 14 to 16 hours to install. The trusses were constructed on the arena floor last week.

Engineers and construction experts have been working for months with contractor Tri-City Erectors, whose workers weld and bolt the steel, plotting out the procedure and sequencing of the truss installation, painstakingly working through the process step by step.

Because of the tight, urban setting, everything was done inside the arena. The trusses, which will run north to south, were too large to transport intact from the Erie factory where their elements are being fabricated.

The trusses will be lifted into place in two or three pieces, a piece at a time, by cranes situated on the arena floor. As soon as one truss is lifted to the roof, workers on the ground will begin assembling the next truss.

At the same time, other workers will begin to extend the roof itself: a high-tech sandwich of steel decking, insulation and rubberized roofing membrane, following each truss as it is lowered into place. That will leave less and less room to maneuver each subsequent piece.

In all, the job will take more than 50 workers to complete.

Getting the roof in place is critical to provide shelter from the elements, allowing workers to begin building weather-sensitive elements of the interior. Roof erection could take as long as 10 weeks, once it gets started.

The $177 million arena — home of the minor league Lehigh Valley Phantoms and the centerpiece of a plan to revitalize downtown Allentown — has a completion target of fall 2014, roughly a year away. When complete, it is expected to hold up to 10,000 spectators for concerts. It has been funded using a special tax district called the Neighborhood Improvement Zone.

Source: The Morning Call