Work on G.I. bridge planned for next year

by Sherry Hamilton - Posted on Oct 10, 2018 - 02:05 PM

Gwynn’s Island residents learned during a meeting with VDOT officials on Thursday night that work is being planned on the island’s bridge for next year.

Fredericksburg District Bridge Engineer Annette Adams with the Virginia Department of Transportation told a packed house at the Gwynn’s Island Civic League building that the center bearing on the pivot pier is slated for replacement because of wear from repeated openings and closings.

In addition, the steel trusses and mechanical support members are due for rehabilitation work, along with the bridge’s mechanical and electrical systems. Adams said that one of the diesel engines will be replaced with an electric motor. One diesel engine is required to remain in place because of the possibility of electrical outages, she said.

The problem that caused the bridge to become stuck open on hot days this past summer had to do with the clearance on the island side of the swing span, she said. After successively long hot days, followed by warm nights, the metal on the bridge was expanding and didn’t have a chance to cool down and contract. When the bridge was in the process of being closed, Adams said, the swing span was hitting up against the “rest bent,” or the place where the swing span sits when it’s in the closed position, and “it was really hard to cool it down” and get it into a position to lock it. Workers also discovered during the last construction project that the nosing had been welded into one position, and they corrected that, she said. If the problem occurs again next summer, she said, “we can move quickly to address it.”

Adams said the Commonwealth Transportation Board is investigating funding avenues for special structures such as the Gwynn’s Island bridge, with a report due in December. The work is expected to be advertised sometime in the spring, said Adams, and the projected cost is $5 million-$6 million.

In response to a question from an audience member, Adams said the repair work would likely take nine months to a year, during which time there may be a need for single-lane traffic. She said the work may not be continuous, but may be completed in increments of three months each.

Another audience member suggested that there would be an increase in truck traffic on the bridge once an oyster-processing business on the island ramps up expanded operations. Adams said she had just heard about the oyster operation that day, but that the bridge is not load-posted. She said the goal is not to have a weight limit during construction, although there might have to be a restriction on special-use vehicles that are overweight.

A resident who identified himself as a captain with the fire department asked if a radio could be placed in the tender house so the tender knows when a situation might require an emergency vehicle to cross the bridge, and Adams said she would make that happen.

She said she was committed to the project. “If you have to shut it down in either direction, boats can’t get out of Hole in the Wall or traffic can’t get off the island,” Adams said. “We’ve got to make sure we’ve got the power to do what we need to do. We can’t treat it like other bridges. There is no other way.”

Bridge facts

Adams said that the Gwynn’s Island bridge is the oldest moveable bridge in Virginia and that it opens the most. Records show the bridge opened 1,787 times in 2014, 3,030 times in 2015, and 2,031 times in 2016. Because the bridge crosses over the water under a U.S. Coast Guard permit, it is required to open on demand 24 hours a day, seven days a week.

The channel over which the bridge passes was established by the 53rd U.S. Congress, which served from 1893-1895, said Adams. It was improved in 1899 by the 55th Congress at a cost of $12,500.

Built in 1938, the bridge is 732 feet long and has 24 feet between the curbs. The moveable span is 207 feet long. The vertical clearance for boats passing under the bridge is 11 feet when closed; the horizontal clearance is 80 feet.

The general condition of a bridge is rated on a scale of 0-9, with nine being the best, said Adams. A five is fair and a six is good. The Gwynn’s Island bridge deck and substructure are rated at six, she said, while the superstructure is rated at five.

Adams gave a quick rundown of work that’s been done on the bridge over the years, including the addition of a walkway for workers in 1954; deck replacement in 1964; installation of pile jackets to protect the concrete pilings in 1967; numerous repairs to the tender house; refurbishing of the machinery in 1986; repairs to the electrical system, swing span and concrete in 1996; painting in 2000; repairs to the roadway’s substructure and superstructure in 2006, small structural steel repairs in 2009, and repairs to the tender house and traffic gates, along with improvements to the signal and an electrical upgrade since 2013.

“It shows we have been paying attention to this vital structure,” said Adams.