Stabilizing the Port of Alaska

Just a couple of miles from the Port of Alaska’s visitor center sits a Manson trailer that serves as the home base for the North Extension Stabilization Step 1 (“NES-1”) project team. For the past three years, this team has worked to remove a deteriorating section at the port, reshaping the landscape as part of the Municipality of Anchorage’s 10-year Modernization Program—an initiative that will introduce new marine structures and re-shape the port to support both commercial and military vessels and strengthen the national economy in the Last Frontier.

The derrick barge VIKING at the NES-1 project.

The project spanned three work seasons, with a rotating crew from January 2023 through September 2025. In the spring and summer of 2023, Season 1—led by Project Manager Drew Paup and Construction Manager and Superintendent Erik Dolmseth—focused on earthwork and groundwork. Subcontractors Granite Construction (“Granite”) and Condon-Johnson & Associates collaborated to enhance and stabilize several sections of the site through excavation, deep soil mixing, and rock placement.

Manson field crews then mobilized to NES-1 the following spring to begin Season 2 dredging, pile extraction, and continued rock placement across the site. The team efficiently coordinated operations using the derrick barges VIKING, VALHALLA, and VULCAN to conduct production and relief digging, as well as pile extraction.

“The majority of the work for Season 2 involved excavating material and pulling out the old sheet piles that were installed from a failed project several years ago,” says Project Engineer Ian Walker. “Granite returned for another season of rock placement and also provided support during pile extraction operations.”

The derrick barge VIKING dumping material onto the flatbarge NORTHPORT.

Using the DB VIKING, the crew dredged material along the southern portion of the site in Season 2. Meanwhile, the VALHALLA and VULCAN crews worked together on pile extraction. The VALHALLA used a clamshell to remove the topsoil and expose the worn sheet pile walls, while the VULCAN performed relief digging to loosen the tightly packed material around the piles, often five to ten feet deep. Switching between an APE 200 and APE 250 vibratory hammer, the VULCAN extracted piles across various segments of the 6,200 linear feet of existing sheet piles. Thanks to the fast-paced dredging work, the VIKING eventually took over pile extraction from the VULCAN.

After pile extraction, Granite transported and placed revetment (a sloped structure composed of rock or hardened material designed to prevent erosion) along the shoreline to absorb wave energy and protect the landside of NES-1.

With so many moving parts, Manson’s project team emphasized the importance of clear communication and building trust among all parties involved.

Dozers perform rock revetment along the shoreline at NES-1.

“With all these features of work and equipment going on all at once, we made it a point to keep communications clear with Port of Alaska and Granite personnel,” says Season 3 Project Manager John Henriksen. “We’ve built an excellent relationship with everyone on the job and found it important to meet regularly to discuss what is going on for that particular week.”

As autumn 2024 approached and the weather changed, Manson demobilized from NES-1, looking forward to wrapping up dredging and revetment placement in spring 2025.

John and Ian returned to NES-1 in April 2025 along with Project Engineer Jeffrey Paup. With most of the dredge work nearly finished, the VIKING returned to complete the job, accompanied by the NORTHPORT and M58 and M70 flat barges.

Supported by tugboats HARRY M and PETER M, the VIKING dredged the remaining shoreline sections from April to September 2025. Both operations were deemed successful by the project team, who credits the crew’s experience for their achievements.

People like Leverman Brad Schwiger and the team on the VIKING are a big reason why the project was able to move along at an efficient rate, according to John. “The seasoned personnel are laser-focused on getting the job done and have even taken the time to teach some of the newer members of the crew on what to do.”

All machines on deck at NES-1: Derrick barges VALHALLA and VIKING clamshell dredging while the Manitowoc 4100 land crane pulls sheet pile.