Tacoma’s beloved but crumbling Murray Morgan Bridge might need to be locked in the upright position later this year to relieve tension on its cables, according to the state Department of Transportation.
But city officials want to make sure every alternative is considered before such a drastic step is taken. The bridge was closed to vehicles in October but remains open to pedestrians and bicyclists.
Jim Parvey, the city’s interim engineer, said he plans to meet later this week with a DOT official to talk about the bridge, including possible alternatives to cutting off pedestrian access.
Earlier this month, state officials informed city officials that the bridge needs to be raised in the upright position. With the lift span so locked, engineers could relieve the weight of the counterbalances, which would take tension off the cables.
The recommendation to keep the bridge up was included in a 2007 study of the Murray Morgan paid for by the state. It recommended that the bridge be inspected within six months and out of operational service within 12 months, said Kevin Dayton, DOT regional administrator.
“There is no reason to think the findings they made are no longer necessary,” Dayton said.
Raising the bridge is the most cost-effective solution – about $1 million – to the cable problem, and it doesn’t interfere with Tacoma’s plans for eventually rehabilitating the span, Dayton said.
Locking the bridge in the upright position is one of the first steps the city would take to rehab it, he said.
The only alternatives, according to Dayton, are replacing all of the wire ropes, or replacing both the wire ropes and the shivs and the trunnions. Those options cost at least $2 million.
“All that would give us is the ability to open and close it to marine traffic,” Dayton said.
State officials conducted a pedestrian count and found about 40 people per day use the bridge, Dayton said.
City officials don’t dispute the condition of the cables.
“We hate to lose the pedestrian access, but there clearly is a problem with the cables,” Parvey said. “It’s a pretty drastic action,” he said of locking the bridge in the upright position.
Since the bridge was closed to vehicles, a consultant working for the City of Tacoma has concluded it can be rehabilitated for approximately $80 million.
About $40 million has been set aside for the work. The cost of locking the bridge upright or replacing any cables would come from that fund.
It’s not clear when the bridge might close completely. It likely would happen late this year or early in 2009, Dayton said. Parvey predicted it could happen as early as November.
Jason Hagey: 253-597-8542
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