The USS Pennsylvania, an Ohio-class ballistic missile submarine, enters Dry Dock 4 at Puget Sound Naval Shipyard in Bremerton, Wash., in May 2023. The dock can be drained of water, allowing workers access to the entire hull of submarines. (Puget Sound Naval Shipyard)
BREMERTON, Wash. — The U.S. Navy plans to invest $377.7 million to strengthen Dry Dock 4 at Puget Sound Naval Shipyard & Intermediate Maintenance Facility, enhancing its survivability in the event of a major earthquake in the Pacific Northwest, the Navy announced Tuesday.
The project, awarded to Kiewit-Alberici Joint Venture, is part of the Pentagon’s 20-year, $20-billion Shipyard Infrastructure Optimization Program (SIOP) to overhaul all four of the nation’s public shipyards in Puget Sound; Pearl Harbor, Hawaii; Norfolk, Va.; and in Kittery, Maine.
Recent Government Accountability Office surveys have indicated the cost of the SIOP program could be significantly higher; retrofitting the Pearl Harbor Naval Shipyard alone could cost up to $21 billion.
The shipyard on the Kitsap Peninsula just west across Puget Sound from Seattle is the “primary provider for the maintenance, repair, modernization, inactivation and disposal of ships, submarines and nuclear-powered aircraft carriers in the Pacific Fleet,” the Navy said in a statement.
Naval Facilities Engineering Systems Command Northwest is providing oversight on the project.
In early 2023, the Navy temporarily closed three dry docks at the shipyard after seismic assessments revealed vulnerabilities to major earthquakes. A delta pier at the nearby Trident Refit Facility in Bangor, home to ballistic missile and attack submarines, was also shut down.
The Puget Sound Naval Shipyard is the Navy’s top facility for maintenance of nuclear-powered submarines of the Pacific Fleet. (Joseph Paolucci/U.S. Navy)
Initial retrofitting began in 2023, with anchors installed through Dry Dock 4’s walls to reinforce its structure. The Navy ultimately plans to replace Dry Dock 4 by 2040.
The shipyard is located about 100 miles east of the offshore Cascadia Subduction Zone — a 700-mile fault stretching from British Columbia to Northern California.
According to the Pacific Northwest Seismic Network, the zone has produced seven major earthquakes in the past 3,500 years, with recurrence intervals of 400 to 600 years. Other estimates have that number at as little as 250 years.
The last occurred in 1700. The National Seismic Hazard Model created by the U.S. Geological Survey estimates a 15% chance of a magnitude 8.0 or greater quake in the Seattle area in the next 50 years.
A magnitude 9.0 event could trigger tsunami waves up to 100 feet. Most Navy installations in Puget Sound are shielded from direct wave impact. However, the earthquake shaking would damage facilities and lead to flooding in low-lying areas around the shipyards.
“The Navy is committed to investing in its infrastructure to ensure it remains operational and resilient,” said Capt. Preston Taylor, commanding officer of NAVFAC Northwest.
The retrofit is being conducted during a period when no submarines are scheduled for dry dock, ensuring that the work does not impact strategic deterrence or fleet readiness, the Navy said.
Aerial view of Puget Sound Naval Shipyard and portions of the adjacent Naval Base Kitsap. (U.S. Navy)
