InfraStructures - August 2011 - Manitowoc 888 RINGER well-suited for dam replacement

Manitowoc 888 RINGER well-suited for dam replacement

A Manitowoc 888 crawler crane mounted on a RINGER® attachment helped replace a navigational lock gate at the John Day Dam on the Columbia River between Oregon and Washington. The downstream navigational lock gate is 34.4 m tall, making it the tallest lock in the United States.

The 900 kg gate was removed and replaced in four sections, with the heaviest load for the Model 888 weighing 260,000 kg. The contractor faced various challenges when performing these heavy lifts because the crane was mounted on a barge.

Advanced American Construction, Inc., the contractor for the project, chose a Manitowoc 888 RINGER to reduce the load radius that would otherwise be required when lifting on land. Essex Crane Rental Corp. rented the Manitowoc 888 to Advanced American.

Advanced American chose the Manitowoc 888 not only to meet its capacity requirements, but also for its reach. The project required removing and replacing two components weighing 59 t each from the roof of the lock towers more than 40 m above the barge.

The inherent instability of working on a barge also presented several challenges. The contractor used a self-contained ballast system to transfer water between hull tanks to steady the barge as the crane hoisted each load. Maintaining balance was critical because, for the crane to complete the picks, the bow of the barge needed to be secured within six inches of the dam.

Kainan Bodenlos, project superintendent for Advanced American Construction, Inc., said that support from Essex and Manitowoc made the project a success.

The Manitowoc 888 RINGER has a capacity of 600 t and a maximum jib capacity of 250 t. It has a 132.5 m maximum radius and a 13.7 m diameter ring. For this project, the crane was rigged with 76.2 m of boom and 635 t of counterweight.

The work on the John Day Dam is part of a larger maintenance and repair initiative including the John Day, Dalles, and Lower Monumental dams along the Columbia-Snake rivers. The project, which includes replacement of the gates, drive machinery, and electrical systems, began in October 2010 and was completed in March 2011.

Source: The Manitowoc Company, Inc.