In spite of heavy rain and wind, crews working on the Murray Morgan Bridge have finished the most technically challenging phase of the $57.4 million restoration project.
After a series of time-consuming setbacks, workers hoisted four giant steel pulleys – each more than 9 feet in diameter and weighing about 13 tons – to the top of the downtown Tacoma drawbridge, where they’ll be used to raise and lower the century-old lift span.
Assuming all goes well this week with cable work and removing temporary structures built to support the bridge during the lifts, the 1,760-foot-long bridge could be open to vehicles and pedestrians by the end of December, according to Tom Rutherford, the City of Tacoma engineer in charge of the project.
But Rutherford is sounding less confident about the opening date than he has in the past.
“That’s what we’re shooting for,” he said, “but it’s getting pretty tight. There’s still a lot of work left to do. It’s going to be a beehive of activity to get everything done by the end of the month.”
The bridge definitely will be open to traffic in time for its 100th anniversary, Rutherford said. The bridge originally opened Feb. 15, 1913, and the city plans a celebration on that date next year.
The Murray Morgan Bridge was known as the 11th Street Bridge or City Waterway Bridge until 1997, when it was named for Morgan, a much loved local journalist and historian who worked as a tender on the bridge in the 1950s.
The state Department of Transportation closed the bridge to vehicles in 2007 because of deterioration and structural deficiencies. The state transferred ownership to the City of Tacoma in 2009.
The bridge restoration contractor, PCL Construction, planned to replace the giant pulleys – or “sheaves” as bridge engineers call them – in August.
But just hours before the first lift was to take place, the lift span shifted slightly on its temporary support structure, tossing three 240-pound steel plates into the Thea Foss Waterway and twisting construction scaffolding.
No one was hurt in the incident, but redesign and replacement of the support structure delayed the sheave lifts for three months.
EARLIER TROUBLE
That was the second notable setback for bridge restoration.
On or about Thanksgiving 2010, copper thieves ransacked the powerhouse on top of the bridge, causing between $250,000 and $300,000 in damage.
The thieves pulled 300 to 400 pounds of copper wire out of conduits leading to the powerhouse, where electric motors and a series of gears raise and lower the structure. In the process, they ruined the century-old control center and left the bridge stuck in the down position.
2 PHASES
The bridge restoration work is being done in two phases. The first phase, which is close to completion, was financed primarily with state and federal grants.
One part of that work that won’t be completed this year is a pedestrian elevator to deck level from the northern side of the bridge at Dock Street, which will provide access required by the Americans with Disabilities Act.
Additional seismic work on the bridge will be required after this phase of rehabilitation is completed.
Work on the superstructure has improved its resistance to earthquakes, Rutherford said, but it hasn’t brought the bridge up to current seismic standards.
“We didn’t have enough money to do everything,” he said. “There will have to be some work done to the subsurface on both sides and probably some work on the piers themselves, to withstand seismic events.”
Engineers have not yet completed a cost estimate for the remaining seismic work.
The on-land portion – using stone columns and grout to reinforce the surrounding earth and make it more resistant to liquefaction – has been estimated at $2 million, Rutherford said.
Cost of work needed on the piers has not yet been estimated, he said.
Rob Carson 253-597-8693
rob.carson@thenewstribune.com
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