10″ Pipe Line Constructed Across Turnagain Arm in Alaska’s Cook Inlet.
Associated’s crews were strongly challenged by nature in laying a 10 inch pipeline across Turnagain Arm, near Anchorage. This dead end waterway, which once frustrated the famous Captain Cook on his search for a passage to India, has the second highest, tide fluctuation in North America, reaching 38 feet at certain periods. At each low tide, our lay barge came to rest on the sea floor, dramatically halting construction. But, as the picture illustrates, we were able to see the underwater trench and to daily note our progress along the right-of-way. Naturally, these extreme tidal conditions resulted in incredibly strong currents. As the waves advanced or retreated, our lay barge required extra strong moorings to hold our position, to prevent separating from the pipeline. Despite these unusual conditions, our crews successfully completed this Alaskan pipeline.
Associated Builds Important Segment of Trans-Alaska Pipeline.
Right-of-way preparation was an essential phase in the construction of the trans-Alaska pipeline project. Environmental requirements and governmental regulations dictated that all operations be performed from a work pad. A year before start of actual pipeline construction, tons of gravel were hauled in, spread, and leveled to grade in the construction of the work pad. An all-weather steel-girdered bridge crossing the Yukon was completed in 1976. This bridge paralleled the pipeline right-of-way. We installed the 48-inch pipeline on the side of the bridge for the aerial crossing of the Yukon the same year. Prior to completion of this bridge, we operated a 130-ton hovercraft as a ferry in the summer and as an air-cushioned transport after the river iced over in the winter.
We encountered many varied and unusual conditions during the construction of this remarkable pipeline system. Temperatures ranging from +90° F to below -60° F. Permafrost, mountainous terrain with over 30 degree slopes, hard rock, dense forests, caribou migratory trails, and hibernating bears were among the more memorable problems we faced. At the end of 1975, we had completed 60 percent of the pipe laying activities required in Section 4.
In 1976, we completed all pipe laying operations, including the installation of 46 miles of above ground pipeline and 12 miles of buried pipeline. In addition to the 127 miles of 48-inch pipeline that we installed in Section 4 over the two-year period, we also constructed 16,154 vertical supports, 27 mainline valves, and installed 94.4 miles of insulation on the above ground sections of the pipeline. Now in full operation, the trans-Alaska pipeline system transports two million barrels of crude oil per day from the wells on the North Slope to the pipeline terminal and ice-free port at Valdez, Alaska. We felt gratified to have been chosen as one of the execution contractors in the construction of this great pipeline system. We are especially proud of all our personnel assigned to this project who worked long hours under very difficult conditions to establish our company as the leading contractor on the entire system. The experience that our people gained on the trans-Alaska project has been invaluable in our company’s subsequent pipeline projects.
Doyon Associated, LLC
Doyon Associated, LLC (DAL) was established in 2006 when Associated Pipe Line Contractors along with Doyon Oilfield Services, a subsidiary of Doyon, Limited, an Alaska Native Regional Corporation, formed a strategic partnership that specializes in arctic pipeline construction and associated infrastructure. DAL’s corporate culture places a high value on safety; embodies respect for employees, subcontractors, vendors, and customers; and ensures compliance with state and customer requirements and regulations.
This partnership provides extensive knowledge and collective experiences from multiple projects spanning many years, including valuable expertise on Alaska’s North Slope. DAL has a proven track record for successful completion of projects under challenging conditions, while maintaining corporate commitment to workplace safety, protection of the environment, and quality of service. DAL’s continued effort to improve construction efficiency have led to innovative implementation of unique solutions to problems affecting pipeline productivity in the extreme arctic environment.