WASHINGTON — The U.S. Navy will immediately suspend submarine repair work at four dry docks in Washington state, following new concerns about their ability to withstand seismic activity, service leaders told Defense News.

The Navy identified new concerns related to dry docks 4, 5 and 6 at Puget Sound Naval Shipyard as well as the dry dock at Trident Refit Facility Bangor, two service officials told Defense News on Thursday.

They stressed there is “no immediate risk” and that this step is strictly preventative, allowing a team of more than 100 experts to more fully study the four dry docks and better understand what mitigation steps are required for longer-term safety.

All four dry docks are currently empty and do not have any imminent submarine maintenance availabilities planned, the officials said. The team has the support of Navy leadership to move as quickly and safely as possible to get the dry docks operational again and minimize the impact to the fleet.

This disruption comes at a time when the submarine force is already strained — 18 attack submarines fleetwide are in a maintenance period or pierside waiting to enter one, nearly double the number of subs that should be sidelined for maintenance, per Navy scheduling assumptions.

Puget Sound Naval Shipyard is the primary location for attack submarine and aircraft carrier maintenance on the West Coast. Trident Refit Facility Bangor tends to the West Coast ballistic missile submarine fleet.

The Navy routinely conducts seismic risk assessments on all ashore facilities in earthquake-prone areas. The service has previously performed several of these assessments at Puget Sound and took corrective actions based on the results.

This time, however, more modern scientific techniques and technologies cued the Navy to concerns of which they were previously unaware. So-called Level 1 and Level 2 seismic events “could potentially cause dry dock structural failures that pose a risk to our sailors and workforce and damage to our submarines,” an official explained.

Naval Facilities Engineering Systems Command and other commands conducted this study last year “with a goal of better modeling of potential outcomes of several types of major earthquakes,” one official said. The firm WSP USA conducted the engineering analysis and submitted its findings in late October, identifying “potential dry dock failure during a seismic event and the necessity to postpone docking submarines in the four affected locations as safety of the shipyard workers, the surrounding community, preservation of the environment are of utmost concern to the Navy.”

Since October, “short-term mitigations have been put in place, and it’s really important here that these were proactive steps taken in order to ensure the safety of our sailors, shipyard workforce, the public and the environment,” another official said.

The effort culminated in the decision, announced to the Puget Sound and Bangor workforce Friday, to cease operations at these four dry docks until further assessment and mitigation takes place.

The officials said all the dry docks in the area were built at different times and under different Navy construction codes. Other dry docks at the yard will remain active, including Dry Dock 2, which is currently working on the guided-missile submarine Ohio.

An official said the concern over these four particular dry docks is directly tied to the nature of their design and construction.

As for next steps — as well as potential timelines and costs associated with the mitigation work — an official said that “it’s too early to tell.”

“We’ve been asked and tasked this week to come up with mitigations to put in place to address some of the concerns the seismic study has put in place. But at this stage it’s just too early to tell” what will come of the discussions, the official explained.

The official added that more than 100 experts from the Navy, the Defense Department and private industry have gathered to look at the dry docks, put forward a range of mitigation proposals and select the right ones to pursue.

Given the top-level support, an official said, current-year money will be found to immediately fund these projects, rather than waiting to insert them into future budget year plans.

The officials also noted that “the shipyard’s workforce size and workload demands will not change because of these temporary measures,” largely because there aren’t any dry docking availabilities getting canceled or delayed in the near term.

Puget Sound Naval Shipyard and Trident Refit Facility Bangor “are working with the fleet to mitigate impacts to ship schedules. The work packages for each availability are being evaluated and structured to continue work pier-side when possible. As our mitigation plan moves forward, we will have a better understanding of future impacts to availabilities,” an official said.

Megan Eckstein is the naval warfare reporter at Defense News. She has covered military news since 2009, with a focus on U.S. Navy and Marine Corps operations, acquisition programs and budgets. She has reported from four geographic fleets and is happiest when she’s filing stories from a ship. Megan is a University of Maryland alumna.

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