The US Navy Portsmouth Naval Shipyard (PNS) has completed an extended docking selected restricted availability (EDSRA) of Virginia-class attack submarine USS California (SSN 781).
The nuclear-powered vessel was delivered back to the fleet on 15 June.
USS California entered drydock to undergo the extensive overhaul at PNS in May 2019.
According to a US Navy estimate, EDSRAs require 200,000 days of labour and much longer in practice.
The availability includes performing maintenance, repairs, and upgrades on the submarine in dry dock. It mostly focuses on the vessel’s hull, propulsion, and other systems.
The Virginia-class maintenance cycle was adjusted by the US Navy. Before 2015, the maintenance cycle was only four years.
California Project Superintendent Dave Simoneau said: “The workforce at Portsmouth Naval Shipyard and the crew of California have proven what teamwork, respect, and ownership can accomplish.
“The success achieved in maintaining the EDSRA schedule is the direct result of these men and women leaning in and owning it every day.
“They are the reason we are able to win the ‘Race to Combat Readiness’ and return California to the Fleet in record time to help protect our nation.”
California is the seventh navy ship and first submarine to be named after the US state and the eighth Virginia-class boat.
According to Navy policy, the service’s four public shipyards must deliver majority of maintenance on US nuclear-powered fleet.
The other three shipyards are Norfolk Naval Shipyard in Portsmouth, Puget Sound Naval Shipyard in Bremerton and Pearl Harbor Naval Shipyard.
PNS commander captain Daniel Ettlich said: “There is immense pride in knowing PNS bought back time for fleet-readiness.
“It is a monumental accomplishment to return California to the seas, combat-ready and modernised, to support our national security despite the once-in-a-century obstacles brought forth by Covid-19.”