Puget Sound Naval Shipyard begins major earthquake resilience upgrade
Seismic analyses have found that Puget Sound is particularly vulnerable to earthquakes (Source: Jelson25, wikimedia)
The US Navy has committed USD 377.7 million to strengthen Dry Dock 4 at Puget Sound Naval Shipyard & Intermediate Maintenance Facility. The work is designed to enhance the dock’s resilience to a major earthquake in the Pacific Northwest.
The contract has been awarded to Kiewit-Alberici Joint Venture under the Shipyard Infrastructure Optimisation Program (SIOP), the Navy’s 20-year, USD 20 billion initiative to modernise all four US public shipyards. Recent Government Accountability Office reports suggest overall costs could rise well above original estimates.
Puget Sound Naval Shipyard, located in Bremerton, Washington, is the primary West Coast facility for maintenance and overhaul of nuclear-powered carriers and submarines. Dry Dock 4 retrofitting began in 2023 with structural anchoring. The current phase will reinforce the dock further while long-term plans call for full replacement by 2040.
The site sits near the Cascadia Subduction Zone, a 700-mile offshore fault with a history of major seismic activity. Scientists estimate a 15% chance of an 8.0-magnitude or greater earthquake affecting the Seattle region within 50 years.
The Navy confirmed the upgrade is scheduled around fleet requirements. No submarines will be in dock during the retrofit, ensuring operational readiness is not affected.
