Copper thieves ransacked the powerhouse atop the Murray Morgan Bridge around Thanksgiving, causing between $250,000 and $300,000 in damage and dealing a heavy blow to the City of Tacoma’s effort to repair and reopen the historic structure.
The thieves pulled copper wire out of conduits leading to the mechanical room on the bridge, where electric motors and a series of gears raise and lower the structure.
Because of the damage, the bridge is stuck in the down position, unable to accommodate tall vessels passing in and out of the Foss Waterway.
The thieves probably got away with between 300 and 400 pounds of copper, which has a salvage value of about $3 a pound, said Tom Rutherford, the city engineer in charge of the bridge rehabilitation project.
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The heavy expense, Rutherford said, is because of the damage the thieves did to equipment in removing the wire.
“They damaged the control center, and that thing is vintage,” he said Wednesday. “There are no parts for it anymore and no wiring diagrams.”
Construction on the bridge began in 1911 and it opened to traffic in 1913.
The city, which owns the bridge, recently let out contracts to repair it, a $57 million project scheduled to be finished by December 2012.
Most of the control mechanism would have had to be replaced anyway, city spokesman Rob McNair-Huff said, so the damage won’t directly add to the project’s capital cost.
The problem, McNair-Huff said, is that because the raising and lowering mechanism will take the longest to design and build, the replacement was to have come at the end of the construction project.
Now, he said, the city and the contractor are stuck with no way to move the bridge.
The contractor needs to operate the bridge to do the repairs, he said, and the city needs to operate it to maintain the Foss Waterway as a navigable channel.
“Unfortunately,” McNair-Huff said, “because of age of the equipment, there’s really no way to replace what had been damaged outside of buying new equipment, which is not a small cost.”
McNair-Huff said the city has notified businesses and boat owners, alerting them to the problem.
The Martinac Shipbuilding Corp., located on the Foss, particularly depends on the drawbridge, he said, because it routinely works on large vessels.
The city is looking into several temporary fixes, Rutherford said, including attaching winches to the two 500-ton counterweights and hauling them down manually; bringing in a crane to do the lifting, and replacing one of the two damaged electric motors with a lighter (and much slower) emergency drive motor.
Another option, Rutherford said, is reactivating an old capstan wheel mounted on the bridge, which was once used to raise and lower the bridge manually.
The capstan once operated by county prisoners who walked in circles, turning the wheel, Rutherford said. He calculated it would take about 1,000 revolutions of the wheel to raise the bridge to its open position.
Rutherford, who discovered the copper theft, was unsure of when it occurred, but he said it was between Nov. 22, when the bridge was last raised and lowered, and Dec. 7, when he made an inspection visit.
The thieves gained access by cutting padlocks and climbing a steep stairway, he said. They put plastic tarps over windows to block the light as they worked, and they avoided touching the hot lines bringing 480 volts into the control panel.
“They knew what they were doing,” he said. “If they’d touched those, they’d be goners.”