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Skyway will be lifted 1 inch to make repair

It's a job involving a thin sheet of Teflon. And jacking up the Sunshine Skyway by 1 inch. During the next several weeks, the Skyway will be closed briefly on Saturday mornings while a contractor jacks up the bridge and replaces crucial sliding bearings that allow the huge structure to expand and contract.

Engineers say switching out bearings is not unusual. Similar jobs are done frequently by the state in the routine maintenance of expansion mechanisms. But the top Department of Transportation official for the Tampa Bay area acknowledges that this job is out of the ordinary.

"It is a major undertaking," said Bill McDaniel, district secretary for the Pinellas, Hillsborough, Pasco and Hernando counties. "Anytime you do even the smallest thing on a bridge of that stature, it brings an awful lot of attention."

The $181,000 job is expected to begin Saturday and last for three more Saturdays.

"Though it is a lot of weight and something to respect, we're just going to move very slowly," said Andrew King, who is managing the job for contractor Tom Quinn Co. of Palmetto. "It's all been pre-engineered. We don't anticipate any problem. In fact, it'll be pretty boring."

Eight bearing assemblies are located on the four piers that connect the cable-stayed Skyway with the approach bridges. The bearings allow the main span to expand and contract. As the temperature changes, the Skyway moves back and forth up to 1{ inches a day and about 14 inches a year. Like almost all bridges, the Skyway has expansion joints to accommodate the movement.

"You have to have a mechanism for the bridge to be able to expand and contract," said Joe Blasewitz, project manager for the DOT. "If you don't it would tend to tear itself apart."

King, vice president of Tom Quinn Co., said workers will use two 260-ton hydraulic jacks to raise the bridge deck from the pier by 1 inch. The bearing assembly will be removed and new parts substituted. The Teflon pads that have corroded and slipped part of the way out will be replaced. The two plates that hold the Teflon pad also will be replaced with a new design intended to prevent the problem from recurring.

The bearing pads wore out after three years even though they were designed to last 36 years.

Specifications for the job set forth 24 detailed steps for the jacking operation and replacement of the bearing assembly. Traffic will be stopped during jacking but will resume at lower speeds while the bridge is raised, engineers said. The contractor is required to put down a steel plate over the crack that will be created when the bridge is raised.

An engineering marvel that combines three bridge types, the $244-million Sunshine Skyway opened in April 1987. Seven years earlier one span of the old Skyway was knocked down by a freighter in a rainstorm.

King worked on the construction of the Skyway and also has done similar bearing replacement jobs on the Keys bridges.

"Aside from being high, it's really no different," he said. "You have a procedure. You follow it. You get in and get out and that's the end."