2nd RSW at Ice Harbor Dam Walla Walla Army Corps of Engineers

2nd RSW at Ice Harbor Dam Walla Walla Army Corps of Engineers | 2004-2005

The Ice Harbor Dam RSW is the first production Removable Spillway Weir to be installed on the Snake River. The 1100 ton fish bypass structure was installed in spillbay 1 on the upstream side of the dam. As with the prototype, the RSW is hinged on the dam face and rotates to an up or down position using ballast tanks and a computerized ballast system.

Underwater installation tasks included drilling 16′ x 3.5″ core holes for grout injected anchor bolts using the drill pictured, undercut anchor bolt installation for bearing pads, and side seals. Concrete demolition was also required and state of the art wire saw techniques were utilized to remove portions of the pier nose. The specialized underwater wire saw is shown below. Remove drills, sonar, and sub-sea cameras were used to install the various components required to install the weir.

AUS performed hundreds of dives in depths of up to 135 FSW to complete the project. The project was completed under severe time constraints, on time, and with no lost time accidents. The RSW is operational for the 2005 spring fish migration.

Click here for more information on RSW’s

Sunken Vessel Inspection Pago Pago Harbor, American Samoa CH2M Hill

Sunken Vessel Inspection Pago Pago Harbor, American Samoa CH2M Hill | 2006

The USS Chehalis, a Patapsco class gasoline tanker, commissioned on December 5, 1944, caught fire and sank in 1949 with more than 400 gallons of petroleum cargo and thousands of rounds of artillery shells on board. The American Samoa Environmental Protection Agency is conducting an environmental impact study led by CH2M Hill. The vessel is lying in approximately 150 feet of water about 350 feet off the Fuel Dock at the main port facilities of Pago Pago, American Samoa.

The Port of Pago Pago not only provides virtually all economic viability for the Territory. but also plays an important role in fisheries and recreational activities for surrounding villages. ASEPA must understand potential threats to port operations, to environmental health, and to human safety.

AUS divers conducted an external inspection and provided video images of the orientation, attitude and condition of the vessel; a qualitative description of the character of the sea floor; provided water and debris field samples; identified locations, size and number of gun turrets and guns; identified impediments and entanglement hazards in potential future salvage operations.


From Maritime Magazine by David Cleary

Elm Road Generating Station Wisconsin Electric Power Company

Elm Road Generating Station Wisconsin Electric Power Company | 2005-2007

The Elm Road Generating Station is located on the shore of Lake Michigan in the city of Oak Creek, Wisconsin, approximately 12 miles south of the city of Milwaukee. The project involves the construction of two new coal-fired electric generating units and common facilities to accommodate up to 3,000 megawatts of generation at the site. Offshore construction will affect 22 acres of Lake Michigan through dredging, fill, stabilization, and placement of structures. AUS is the marine subcontractor assisting in the installation of four offshore water intake shafts, 12 foot in diameter. These shafts are 8,000 feet from shore in Lake Michigan.

The AUS divers contribute offshore experience to the heavy lifting and rigging involved in barge mobilization and anchor procedure; rigging and placement of platforms, piles, drill rigs and casings; welding operations on piles, platforms and barges; and drilling operations. The project began in June 2005, with a 2007 completion date.

BP Cherry Point Refinery Piling Inspection and Repair

BP Cherry Point Refinery Piling Inspection and Repair | Annual Contract

BP’s Cherry Point refinery has provided a significant portion of U.S. energy needs for more than 30 years. It is located along Pacific coastal waters in northwest Washington state and is the fourth largest refinery on the U.S. west coast.

The refinery processes a large share of Alaska North Slope crude oil, more than 225,000 barrels a day, into transportation fuels. That’s enough gasoline to keep one million cars on the road each day. It provides about 20 percent of the gasoline market share in Washington and Oregon, 85 percent of the jet fuel at Seattle International Airport, and is the largest west coast supplier of jet and diesel fuel to the U.S. military. Gasoline and jet fuel are also supplied to Vancouver, Canada, and markets in California, Arizona and Nevada. It also produces multiple diesel fuels, propane and butane, and about 2,700 tons a day of anode grade calcined coke used by aluminum smelters, making it one of the largest calcined coke producers in the world.

The refinery once processed Alaska North Slope crude oil exclusively. But with the decline of Alaska crude oil production, the strategic thrust today is to create crude oil processing flexibility with the ability to process low-cost crude oil stocks from a variety of sources. BP employs about 560 full-time workers and 375 contractors, one of which is Associated Underwater Services.

AUS has been inspecting, installing, and maintaining the protection on the pilings that support the many ship docking structures at the BP Cherry Point refinery for as long as AUS has been a company and before. BP’s emphasis on safety is witnessed by their membership in the ISNetworld safety consortium, of which AUS is also a member. The photos show pilings in need of repair and the occasional pleasant encounter with a baby seal.

Round Butte Dam, or Selective Water Withdrawal

Round Butte Dam, or Selective Water Withdrawal | 2007-2009

Round Butte Dam is located about 90 miles southeast of Portland, OR on and adjacent to the Warm Springs Reservation. Portland General Electric determined that a selective water withdrawal and fish bypass structure was necessary to ensure the survival of Summer Steelhead and Spring Chinook Salmon in the Upper Deschutes, Metolius and Crooked rivers. Partially due to unusual currents in Lake Billy Chinook, the downstream fish passage facilities constructed in the 1960’s failed to work properly.

The new system will be a 270 foot structure delivered to the site in pieces and assembled in and on the water. Associated Underwater Services will provide the underwater assembly and installation, topside support and underwater survey and inspection.

AUS will be using the long range Falcon “Sea Eye” with sonar capabilites, as pictured above, to guide and monitor the underwater activities. Barnard Construction is the general contractor, assisted by Dix Corporation. The project will take 3 years and involve drilling and grouting 11 piles 50 feet into the lake bottom, 320 feet below the water surface. The steel structure to be installed is made up of 3 parts. A Selective Water Bottom Structure will be submerged to 270 feet deep and attached to the existing powerhouse intake. A floating Selective Water Top Structure will be positioned directly above the Bottom Structure and connected by the 40 foot diameter Vertical Steel Conduit.

This new structure is designed to draw water in a more natural way to attract fish that will then be screened and released downstream on their way to the Pacific Ocean. Pictures of the actual construction shown include an overview of the site and the structure that will be used to lower the Selective Water Bottom Structure. The red iron is the lift barge, the black iron is the permanent pile structure that gets lowered to the bottom.

Brightwater Conveyance System


Brightwater Conveyance System | 2006 – 2010

King County conceived Brightwater as a major improvement to the regional sewerage treatment system in response to rapid population growth in greater Seattle. The project also will bring important environmental benefits, such as controlling untreated overflows into Lake Washington and Puget Sound, and recycling sewage into irrigation water.

The conveyance system portion of this project consists of 13 miles of new bored soft-ground tunnels. The tunnels extend from Woodinville to Puget Sound. These tunnels will connect about 335 miles of existing sewage pipes to a new 36-million-gallons-per-day treatment plant. From the plant, treated wastewater will flow to a new outfall in Puget Sound. Tunnel construction, currently underway, employs four 14- to 20-foot diameter tunnel boring machines, launched and retrieved via deep shafts in glacial tills well below the water table.Topographic conditions along the tunnel alignment range from hills to intervening valleys, resulting in external groundwater pressures that vary greatly, up to a maximum of 7.3 bars. This geologic factor significantly influenced the design of the tunnel lining system—bolted and gasketed precast concrete segments—and type of tunnel boring machines used for excavation—earth pressure balance (EPB) and slurry shield. In fact, the Brightwater Conveyance System marks the first specified use of slurry shield technology in the United States on a competitively-bid contract.

AUS provides diving services for the East Tunnel Contract and performed a sonar survey to determine configuration and dimensions of shaft. Diving services include, but are not limited to, installation of shear key dowels and rebar mat in the IS and IPS shafts

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