MacArthur Lock, Michigan
LOCATION Sault Ste. Marie, Michigan
CLIENT Detroit District Army Corps of Engineers
PARTICIPANTS Abhe & Svoboda, Inc.
SCOPE OF WORK Concrete Repair & Restoration
VALUE $2.56 million
SCHEDULE December 1998 - April 1999
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A system of channels, canals, and waterways make the Great Lakes accessible to the Atlantic Ocean, and every year hundreds of millions of tons of cargo are transported through the Great Lakes region. Between Lake Superior and Lake Huron is a series of locks known as the Sault Locks. The Sault Locks, which include MacArthur Lock, are the busiest in the world, despite the lakes being frozen and closed to shipping for three months each winter. During winter months the locks are drained and maintenance is performed during an annual shutdown period from December 15th - March 15th. In the winter of 1998/1999 Abhe & Svoboda, Inc. performed major renovations on MacArthur Lock. The MacArthur lock is 800 feet long, 80 feet wide and 30 feet deep, and large enough to handle ocean going vessels. The project involved extensive concrete repairs to the south wall and vertical monolith joints. The concrete repairs consisted of saw cutting around the perimeter of the marked repair areas, chipping out the concrete to a depth of 12 inches, preparing the substrate surface, and forming and pouring the repair areas with a fiber reinforced acrylic polymer modified concrete. Following concrete repairs, the monolith joints were injected with hydrophobic polyurethane resin foam grout, and sealed with an elastomeric joint sealant. During removal of the initial concrete monolith joint, a lead water stop was discovered within the joint, so a change order was issued to excavate the monolith joints the full length of the lock wall to remove all the lead stops. The original contract was designed to excavate the joints halfway down the vertical lock wall, therefore the change doubled the quantity of monolith joint that needed to be removed and replaced within the original contract time. In addition to the concrete repair, abrasive blasting and painting of four lock tainter valve gates, three overlook platforms, and two lock fender booms was performed. Miscellaneous steel repairs were also done, including the removal and replacement of more than 650 steel machinery cover plates, and repairs of damaged/corroded lock wall ladders. About 85% of the work was completed during the winter shut down period of December 15th - March 15th. The remaining work, which involved blasting and painting the tainter valve gates, was performed without interfering with river traffic. The remaining blasting and painting operations took place inside the tainter valve gate chambers within the confined spaces of the lock monolith walls. Despite the major change orders the MacArthur Locks renovation project was finished ahead of schedule and without any injuries. |
