LOWER SNAKE RIVER, Washington – Ice Harbor Dam's navigation lock, located at Snake River Mile 9.7 near Burbank, Washington, returned to service at 11:59 p.m., on Thursday, March 23, according to U.S. Army Corps of Engineers officials in the Walla Walla District.
The Corps investigated and analyzed the unusual “popping” noises and associated reverberation through the gate-hoist drum that occur while the downstream gate machinery of both gate-hoist towers at Ice Harbor’s lock is in operation.
By analyzing data gathered using advanced instrumentation, engineers were able to determine that there was no cause for concern of machinery failure. A slight movement in machinery components has been mitigated to the greatest extent possible; the gate was cleared to return to full, unrestricted operation; and a long-term monitoring plan is being developed from which future recommendations can be made.
Vessel operators and occupants may be able to hear the “popping” noise while the lock gates are in operation, however this “nuisance noise” is not a cause for safety concerns.
The Corps of Engineers conducted an extended navigation lock maintenance outage, December 12, 2016, through March 20, 2017. The coordinated 14-week-long closure affected all eight Corps navigation locks on the Columbia and Snake rivers, during which time critical, non-routine repairs and maintenance, plus routine maintenance and scheduled improvements were completed.
As previously announced, Bonneville, McNary, John Day, The Dalles, Lower Monumental and Lower Granite dams returned their locks to service prior to the targeted March 20 extended outage end date. Ice Harbor and Little Goose dam's navigation locks, on Washington's Snake River, could not be returned to service by March 20 because of on-site work complications. Little Goose Lock and Dam, located at Snake River Mile 70.3 near Starbuck, Washington, is currently estimated to reopen their lock at 11:59 p.m. on April 2.
For more information about the 2016-2017 Columbia-Snake Rivers Extended Navigation Lock Outage, visit the Corps’ webpage http://www.nww.usace.army.mil/Missions/Navigation/FY17LockOutage.aspx.
Release no. 17-039