The Navy finished interim seismic repairs to a dry dock at the Puget Sound Naval Shipyard & Intermediate Maintenance Facility (PSNS & IMF) in Bremerton, Wash., with two more left to be finished, the service said this month.

The mitigation repairs were finished on Dry Dock 4 at PSNS & IMF and the Navy said it has already been tested and recertified, with the USS Pennsylvania

(SSBN-735) docked for its extended refit period on May 11.

U.S. Navy Sailors and Puget Sound Naval Shipyard and Intermediate Maintenance Facility (PSNS-IMF) workers shift the aircraft carrier USS Nimitz (CVN-68) from its homeport pier in Bremerton, Wash., to a dry dock in PSNS-IMF on March 1, 2018. (Photo: U.S. Navy by Mass Communication Specialist 3rd Class Bethany Woolsey)
U.S. Navy Sailors and Puget Sound Naval Shipyard and Intermediate Maintenance Facility (PSNS-IMF) workers shift the aircraft carrier USS Nimitz (CVN-68) from its homeport pier in Bremerton, Wash., to a dry dock in PSNS-IMF on March 1, 2018. (Photo: U.S. Navy by Mass Communication Specialist 3rd Class Bethany Woolsey)

“The mitigation efforts updated existing emergency response plans to better address the chance of a catastrophic earthquake, along with improved early-warning employee notification systems in the dry docks,” the Navy said in a May 12 news release.

The Navy said construction efforts include “drilling holes for the installation of anchors inside the dry dock walls to enhance structural integrity and ensure the safety of the workforce, community, environment, and submarines. The mitigation efforts updated existing emergency response plans to better address the chance of a catastrophic earthquake, along with improved early-warning employee notification systems in the dry docks.”

In January, the Navy first announced four dry docks at PSNS & IMF and the Trident Refit Facility (TRF) in Bangor, Wash., were being closed due to concerns they could not withstand earthquakes after the service conducted a seismic assessment as part of the Shipyard Infrastructure Optimization Program (SIOP) refurbishment effort.

Then, by February, the Navy started mitigation efforts at one dry dock at PSNS & IMF and another at TRF. The Navy had said after those first two dry docks are returned to full service then the other two would undergo repairs.

In March, the Navy awarded the Kiewit–Alberici joint venture a $71 million modification to install and construct risk mitigation measures at Dry Docks 4 and 5 at PSNS & IMF and the TRF dry dock, added on top of a previous $76 million task order for work at these three dry docks (Defense Daily, March 10).

Later that month, Navy officials told congressional committees the repairs to dry docks at PSNS & IMF and the Trident Refit Facility were due to be finished by June (Defense Daily, March 30).

Chief of Naval Operations Adm. Mike Gilday said the first one at TRF Bangor would be finished by June while two of the other dry docks were to be finished by April and May.

The Navy release said mitigation work is continuing at Dry Dock 5 in Bremerton and the TRF.

“This seismic mitigation project is a huge undertaking with a lot of moving parts. The Navy is working as quickly and safely as possible to return our dry docks to full functionality, and I extend my sincere gratitude to everyone who has been involved thus far,” Capt. Jip Mosman, commander of PSNS & IMF, said in a statement.

The dry dock at Trident Refit Facility Bangor (TRFB) in October 2022, used to conduct hull maintenance on ballistic missile submarines and other work requiring a submarine to be out of the water. (Photo: U.S. Navy by Michael Hatfield)
The dry dock at Trident Refit Facility Bangor (TRFB) in October 2022, used to conduct hull maintenance on ballistic missile submarines and other work requiring a submarine to be out of the water. (Photo: U.S. Navy by Michael Hatfield)

The service noted immediate modifications are no longer needed to Dry Dock 6 because “based on future planned improvements to Dry Dock 6 and differences in ship design and the size of aircraft carriers, it was determined immediate seismic mitigations are not required. Aircraft carrier maintenance at PSNS & IMF remains unaffected.”

The Navy said the need to mitigate the remaining docks will be determined once the current work is complete. Other mitigations “may include stability enhancements for submarine availabilities.”

The service underscores experts from Naval Sea Systems Command, Naval Facilities Engineering Systems Command, PSNS & IMF and private industry will keep continuing to plan and implement these structural upgrades “with an eye on the Navy’s future needs and in support of the PSNS & IMF mission to deliver modern, fully-mission capable warships on-time, every time, preserving our national security.”

In 2016, New Yorker staff writer Kathryn Schulz won the Pulitzer Prize for feature writing and a National Magazine Award for a story on the risks of a major earthquake and tsunami in the Pacific Northwest.