Coos Bay Bridge to get facelift

March 10, 2007 11:00 pm

The Associated Press

NORTH BEND, Ore. — It has arched majestically over Coos Bay since 1936, and the McCullough Bridge is seen by some as the grand dame of Oregon coastal bridges.

But the old gal is about to get a facelift.

It shares the fate of many other bridges created by master bridge builder Conde McCullough as U.S. 101, the Roosevelt Highway, was built along the coast.

Years of sea air have slowly corroded the structure, and state planners are trying to reverse the damage before it is too late.

Jared Castle, a spokesman for the Oregon Department of Transportation, said ODOT will begin coating the bridge's concrete limbs in zinc this fall or by winter of 2008 to protect them from further corrosion.

He said the agency has done similar work on other coastal bridges since the 1990s.

Repairs will include an asphalt overlay of the bridge deck and replacement of concrete bridge rails on the south side.

The whole project should take 10 years.

"She's old and she needs a touchup," Castle said.

He said the bridge is structurally sound, but the zinc treatment will help it last longer and is cheaper than building a new bridge.

Castle said the first leg of the project on the mile-long span will take about four years and cost $31 million in state and federal funds. Funding for the rest has not been secured.

"If we had to replace all three sections of bridge, it would be in $300 million to $500 million (range)," Castle said.

The bridge across Alsea Bay at Waldport, also a McCullough project built in 1936, had to be replaced several years ago.

Castle said when the Coos Bay project is done it will look about as it does but be brighter and cleaner.

Project Leader Mark Leedom said the concrete will be sprayed with zinc and that electricity will run through the bridge to draw corrosion away from supporting steel.

"They do the same thing on ships, where corrosion will attack the zinc instead of the steel," Leedom said.

But small pieces of metal in the concrete can interfere with the electrical current.

Castle said bridge workers in the Depression era weren't perfect craftsmen, and often swept nails or bolts into concrete molds.

Today's crews will have to inspect all of the concrete on the bridge. They'll chip out chunks near the surface and use magnets to help find errant pieces, Castle said.

Castle said single lanes on the two-lane structure will experience closures, usually at night when traffic is lighter.

Some daytime closures are expected but Castle said they should be short.

He said ODOT will hold public meetings this spring to advise residents of what to expect.

Castle said these projects typically bring substantial money and jobs to local communities.