The process of lifting the deck sections onto the new Tacoma Narrows bridge was delayed for more than a month by mechanical damage some workers are convinced was sabotage.
Two workers aboard the Swan, the ship that carried the deck sections from South Korea, say 16 motors in hydraulic winches used to move the ship back and forth at anchor were ruined by handfuls of loose screws and washers placed in oil inlets.
The screws and washers mangled the insides of the motors used to move the winches, the workers said, stripping gears, shattering pistons and rendering them useless.
Each of four winches being used to move the Swan is powered by four hydraulic motors. All 16 of the motors were ruined and had to be replaced, the sources said.
Neither worker wanted to be identified, saying they feared losing their jobs. One of the men photographed the damage and delivered pictures to The News Tribune.
The photographs show several disassembled motors, gears with missing teeth and loose screws still stuck inside motor housings.
Erin Hunter, a spokeswoman for the bridge builder, Tacoma Narrows Constructors, said in an e-mail response to questions about the incident that it would be “inappropriate to speculate” about how the screws got into the motors.
TNC is not regarding the incident as sabotage, Hunter said, and did not report it to any law enforcement agency.
TNC moved the Swan into the Narrows on June 29, but the lifting operation did not begin until more than five weeks later.
TNC and the Washington State Department of Transportation attributed the delay in part to problems with the winches aboard the Swan, but did not provide details about the nature of the problem.
The Swan arrived from Korea on June 8 with 16 deck sections stacked four high. The on-board winches are being used to align the stacked deck sections under lifting equipment on the new bridge’s main cables.
Sources said the damaged motors were discovered during initial tension tests June 29 after the Swan was moved into position under the west-side span of the new bridge.
The winches are not part of the ship, but were supplied by the subcontractor Nippon Steel/Kawada Bridge and are specific to the deck-assembly operation.
A worker involved in repairing the motors compared the damage to what would happen if screws were dropped into the engine oil inlet of an automobile engine.
“It is obvious that the screws entered the motors through the hydraulic oil inlet,” he said. “That’s why the screws are lodged into the motor end cap.
“The person who dropped the screws in must have loosened the hoses and put the screws into the hydraulic hoses and waited for the system to be operated,” he said. “The hydraulic pressure would push the screws into the motor and damage the motors when the pressure built up.”
TNC successfully lifted the first deck section into place on the new bridge on Monday.
According to Department of Transportation spokeswoman Claudia Cornish, the bridge builder plans to lift the second section into place today.
TNC had hoped to have all 46 deck sections in place by October. The company’s current schedule calls for finishing the lifts in December.
Asked how long it took to get the motors replaced and reinstalled, Hunter said, “It took as long as required and we continue to target summer 2007 opening.”
The bridge originally was scheduled to open in April 2007, but that date was pushed back three months to July after wire intended used for the main cables corroded while in storage.
Rob Carson: 253-597-8693