The Navy has finished seismic repairs to one of its Puget Sound Naval Shipyard & Intermediate Maintenance Facility dry docks, the service announced late last week.
Ohio-class ballistic missile nuclear submarine USS Pennsylvania (SSBN-735) is now in Dry Dock 4 for a refit after the dry dock received a new certification, according to a news release from the facility.
“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 release reads. “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.”
Following a seismic assessment, the Navy in January announced it would temporarily close three dry docks at Puget Sound in Bremerton, Wash., and the delta pier at the Trident Refit Facility in Bangor, Wash., for overhauls so the infrastructure could better sustain earthquake damage. The service subsequently issued a $76.35 million task order to Kiewit-Alberici SIOP MACC JV for the work in February.
“Mitigation work continues at Dry Dock 5 in Bremerton and the Trident Refit Facility Delta Pier in Bangor. 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 release from Puget Sound reads.
“The need for mitigations in the remaining docks will be determined once current efforts are complete and may include stability enhancements for submarine availabilities.”
The dry docks and the Trident Refit Facility are near a major fault line that runs from Northern Vancouver Island to Cape Mendocino, Calif.
“We’re focused on those portions of the dock that are closest to the nuclear power plant in the submarines,” Chief of Naval Operations Adm. Mike Gilday told the Senate Appropriations defense subcommittee at the time.
“That’s the most substantial work that we’re doing, essentially repairing both sides of the entire dry dock.”