Merwin Trash Rack Replacement

We demolished the existing upper 40 feet of the trash rack at Merwin Dam Unit 2, performed underwater surveys to accurately fabricate a new upper steel section of the trash rack, and installed the new trash rack during elevated lake levels using a combination of our crews and divers.

We had to specially engineer a mobile crane plan on top of the dam due to spatial constraints and modularization of the steel installation. A detailed modular installation plan was formulated based on crane constraints and water elevations to minimize the amount of dive time required for installation.

We also addressed several project challenges. For example, the existing concrete conditions of underwater connection points, which were not found until the existing trash rack was demolished, required expedited material ordering and planning to repair the concrete prior to the new installation. Space constraints on top of the dam limited the size of crane and size of modular steel sections that could be installed.

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