Mystery Solved. Ice Harbor
by Annette Cary
Boats are once again moving through Ice Harbor Dam on the Snake River after engineers investigated a persistent popping noise in the lock's machinery
The dam's lock reopened just before midnight Thursday, according to the Army Corps of Engineers.
The lock was at one of the eight dams on the Snake and Columbia rivers that closed locks for an extended maintenance outage Dec. 12.
The Ice Harbor Dam was supposed to reopen by late Monday, but officials were concerned about unusual popping sounds and then a reverberation through the gate-hoist drum. The 18-foot-diameter drum is used for winding the wire rope that lowers and raises the lock gates.
Machinery for the drum was refurbished during the maintenance outage.
Engineers determined there was no cause for concern after analyzing data gathered using advanced instrumentation, the Corps said.
A slight movement in machinery components was fixed to the extent possible, it said.
People on boats going through the lock may still hear the popping sound, but the Corps said it is a "nuisance noise" and not a safety concern.
Dams at seven of the eight dams have now reopened. The opening of the lock at Little Goose Dam near Starbuck was delayed. It should return to service April 3.
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