14-026 UPDATE #2: Corps progress to fix Little Goose navigation lock gate on track

Published April 18, 2014
Contractor workers at Little Goose Dam remove components of the cracked gudgeon arm assembly on top of the navigation lock’s south gate leaf. The 50-year-old pins required use of an air-arc cutter to remove them.

Contractor workers at Little Goose Dam remove components of the cracked gudgeon arm assembly on top of the navigation lock’s south gate leaf. The 50-year-old pins required use of an air-arc cutter to remove them.

Contractor workers at Little Goose Dam remove components of the cracked gudgeon arm assembly on top of the navigation lock’s south gate leaf. The 50-year-old pins required use of an air-arc cutter to remove them.

Contractor workers at Little Goose Dam remove components of the cracked gudgeon arm assembly on top of the navigation lock’s south gate leaf. The 50-year-old pins required use of an air-arc cutter to remove them.

Contractor workers at Little Goose Dam remove components of the cracked gudgeon arm assembly on top of the navigation lock’s south gate leaf. The 50-year-old pins required use of an air-arc cutter to remove them.

Contractor workers at Little Goose Dam remove components of the cracked gudgeon arm assembly on top of the navigation lock’s south gate leaf. The 50-year-old pins required use of an air-arc cutter to remove them.

Contractor workers prepare Little Goose Dam’s downstream south navigation lock gate leaf for removing the old, cracked gudgeon assembly. This requires installing retaining brackets on the top, and jacking and shoring equipment under the bottom of the gate to keep it stabile against the navigation lock wall during work.

Contractor workers prepare Little Goose Dam’s downstream south navigation lock gate leaf for removing the old, cracked gudgeon assembly. This requires installing retaining brackets on the top, and jacking and shoring equipment under the bottom of the gate to keep it stabile against the navigation lock wall during work.

Contractor workers prepare Little Goose Dam’s downstream south navigation lock gate leaf for removing the old, cracked gudgeon assembly. This requires installing retaining brackets on the top, and jacking and shoring equipment under the bottom of the gate to keep it stabile against the navigation lock wall during work.

Contractor workers prepare Little Goose Dam’s downstream south navigation lock gate leaf for removing the old, cracked gudgeon assembly. This requires installing retaining brackets on the top, and jacking and shoring equipment under the bottom of the gate to keep it stabile against the navigation lock wall during work.

Workers on the gate and in a crane-suspended man basket adjust the diagonal-tensioning nuts on the downstream north navigation lock gate leaf.  Correct tensioning of each gate will help prevent the massive structures from twisting.

Workers on the gate and in a crane-suspended man basket adjust the diagonal-tensioning nuts on the downstream north navigation lock gate leaf. Correct tensioning of each gate will help prevent the massive structures from twisting.

Workers on the gate and in a crane-suspended man basket adjust the diagonal-tensioning nuts on the downstream north navigation lock gate leaf.  Correct tensioning of each gate will help prevent the massive structures from twisting.

Workers on the gate and in a crane-suspended man basket adjust the diagonal-tensioning nuts on the downstream north navigation lock gate leaf. Correct tensioning of each gate will help prevent the massive structures from twisting.

Workers place hydraulic jacks between the downstream north gate leaf and the navigation lock wall to use while adjusting the diagonal tensioning of the gate. Correct tensioning of each gate will help prevent the massive structures from twisting.

Workers place hydraulic jacks between the downstream north gate leaf and the navigation lock wall to use while adjusting the diagonal tensioning of the gate. Correct tensioning of each gate will help prevent the massive structures from twisting.

Contractor workers at Little Goose Dam install the new gudgeon arm assembly on the top of the navigation lock’s downstream south gate leaf.

Contractor workers at Little Goose Dam install the new gudgeon arm assembly on the top of the navigation lock’s downstream south gate leaf.

Contractor workers at Little Goose Dam install the new gudgeon arm assembly on the top of the navigation lock’s downstream south gate leaf.
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Contractor workers at Little Goose Dam install the new gudgeon arm assembly on the top of the navigation lock’s downstream south gate leaf.

Contractor workers take apart the old, cracked gudgeon arm assembly. The pieces were sent to a metallurgy laboratory for a failure analysis.
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Contractor workers take apart the old, cracked gudgeon arm assembly. The pieces were sent to a metallurgy laboratory for a failure analysis.

Contractor workers used liquid nitrogen to shrink the new, bronze bushing, allowing it to fit into the new navigation lock gate gudgeon arm assembly.
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Contractor workers used liquid nitrogen to shrink the new, bronze bushing, allowing it to fit into the new navigation lock gate gudgeon arm assembly.

STARBUCK, Wash. – UPDATE #2 -- Work to replace the cracked gudgeon arm assembly on the top of Little Goose Dam’s navigation lock downstream south gate leaf remains on track to reopen for service by the end of April, according to U.S. Army Corps of Engineers’ Walla Walla District officials.

Work milestones completed to date include securing the gate leaf in place to keep it stabile during repairs; removing the old, cracked gudgeon arm assembly; and painting and installing the new gudgeon arm assembly.

The remainder of the work to be done relies heavily on the use of cranes and man baskets and includes adjusting diagonal tensioning on the gate leafs; preparing the hydraulic power unit for reattachment to the south gate leaf; removing work-related equipment from the site and final alignment testing  prior to returning the navigation lock to service.

For safety, Little Goose Lock and Dam’s navigation lock will remain closed to all river traffic until repairs are completed.

“Many of the tasks involved with this repair have been and will be performed concurrently wherever we can to maximize efficiency and keep this lock outage as short as possible,” said Steve Hartman, Corps project manager. “The Corps is committed to meeting our obligations under the BiOp (Biological Opinion), and to providing safe commercial and recreational navigation services at our locks.”

 

BACKGROUND: The Corps awarded an emergency contract on April 1 to Knight Construction of Deer Park, Wash., to install a new gudgeon arm assembly -- the metal arm at the top of the downstream south gate leaf that hinges and holds the gate leaf to the navigation lock wall.

With the Little Goose lock out of service, the 2014 Federal Columbia River Power System Supplemental Biological Opinion (BiOp) fish transportation scheduled to begin sometime in late April may be delayed. Coordination of fish transportation operations and related research will be addressed through BiOp adaptive management processes.

Little Goose Dam’s navigation lock has a downstream miter gate resembling a giant set of French doors. One gate leaf is about 118 feet tall, 43 feet wide and weighs 334 tons -- from 1986 through 2013, the gate performed 35,713 lockages. A gate gudgeon assembly is a key component of this style of gate, holding the gate into position at the top while the gate pivots to open and close (a hinge-like assembly). The steel gudgeon assembly is an original component of the lock and has not been removed since installation in the late-1960s.

The Corps has notified commercial navigators, fish managers and other stakeholders, and will continue to provide updates as they become available. Public Notices and other navigation lock information are available on the Walla Walla District website at www.nww.usace.army.mil/Missions/Navigation.aspx.

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Contact
Public Affairs Office
509-527-7020
cenww-pa@usace.army.mil

Release no. 14-026