Imagine a construction project that takes you to one of the coldest and most remote places on earth—a project site about 730 miles from the tip of South America across the treacherous Drake Passage and 1,750 miles from the south pole that is accessible only by sea for nine months out of the year with average temperatures typically near freezing or below. It may not sound like the ideal location to build anything.
However, the mission-critical pier at Palmer Station was at the end of its useful life and replacement was inevitable. Palmer Station is a research facility on Anvers Island in Antarctica and is the only U.S. Antarctic station north of the Antarctic Circle. Originally constructed in 1968, the station is operated by the National Science Foundation’s United States Antarctic Program (USAP). The station’s location is ideal for biological studies of the region’s marine ecosystem. The facility also houses year-round monitoring equipment for global seismic-, atmospheric-, and UV-monitoring networks.
Replacing a pier in Antarctica’s extreme climate presented unique challenges for designers and builders, such as planning for a potential encounter with a 40,000-ton iceberg imparting up to 600,000 pounds of impact force. Durability was also a major concern. The new pier needed to accommodate modern mooring and berthing elements for high winds, snow, and ice to safely accommodate existing and future Antarctic research and support vessels.
The project involved replacing the existing cellular cofferdam sheet pile bulkhead with a new high-capacity steel pile founded concrete pier for resupplying the station. The pier will support long-term USAP Antarctic operations and research for the next 50 years.
To succeed, the project required a design resistant to operational loads; extreme environmental forces; and a construction strategy for planning site access, supply chain logistics, and teamwide collaboration. At the start, the team evaluated how the pier structure, fender elements, superstructure, and substructure responded to global loading and specific loading, including ice crushing and berthing impact. Designers then worked closely with the contractor to determine the construction techniques, sequencing, and equipment to be used, including barge and land-based cranes. Planning included accommodating construction during a single construction window (6 months maximum), including scheduling, fuel, supplies, and upland remodeling.
Due to the remote location, the construction team had no access to re-supply or repair facilities, and with no air strip, all necessary personnel, materials, and equipment had to be transported by barge to the site during the summer. Careful planning for the logistics of pre-fabrication, mobilization, shipping, construction sequencing, and demobilization was paramount.
The project’s logistics trail began with component fabrication in Vancouver, British Columbia prior to barge loading in Seattle, Washington. With a final fuel and supply stop in Punta Arenas, Chile, the one-way trip covered approximately 8,700 nautical miles and took two months for the barge tow.
Modular prefabricated components were used to minimize complex, on-site construction and included precast, prestressed, and post-tensioned concrete pile caps and deck panels supported by drilled and rock socketed galvanized steel pipe piles. Connection methodologies included onsite welding, post-tensioning, cold-temperature grouting, and additional weldable reinforcing steel for unforeseen construction conditions.
The Palmer Station pier replacement took six years to design and five months to construct in one of the harshest environments on earth. The new pier has seen its first winter season since construction and is proving to be durable, robust, and capable of resisting extreme environmental conditions and ice impact loads. The project leveraged simplified construction techniques and modern long distance communication technology to design and deliver a pier that will support USAP operations well into the future.
A timelapse video of the pier construction can be viewed here.
For questions or additional information on this project, please contact us at publicrelations@moffattnichol.com.
