PEARL HARBOR, Hawaii -- Pearl Harbor Naval Shipyard & Intermediate Maintenance Facility (PHNSY & IMF) completed all planned maintenance and modernization work on USS Columbia (SSN 771) May 17, delivering the Los Angeles-class fast-attack submarine back to the fleet.

“With challenges to overcome during the availability, seeing her return from successful sea trials and achieving certification shows the results of the collective efforts and dedication of the shipyard team, ship’s force, Submarine Squadron 7, Submarine Forces Pacific and Naval Sea Systems Command,” said Mr. Devin Paiva, USS Columbia Project Superintendent. “We have a shared sense of pride knowing the team stayed focused to deliver Columbia back to her crew, ready to support our Navy and nation.”

Columbia entered dry dock at PHNSY & IMF in October 2018 for the submarine's engineered overhaul (EOH) availability. An EOH is a significant multi-year overhaul, which occurs near the mid-point of a submarine's service life. During this type of availability, the sub receives essential repairs and necessary modernization as well as routine maintenance to her systems.

Columbia’s EOH required more than 394,000 man-days with almost 800 employees supporting the project and completing more than 12,000 individual jobs. The availability officially ended May 17, following the submarine’s successful sea trials and certification.

Columbia's successful undocking July 16 last year marked a significant step towards returning to sea. Once undocked, the project team finished additional maintenance requirements pierside ahead of sea trials.

Ahead of her final certification for unrestricted operations, Columbia’s project team and ship’s crew embarked for sea trials to ensure the submarine can safely operate at total technical capacity. This step was essential for mission capability throughout the sub's designed service life.

While the joint maintenance team faced many obstacles throughout the project including the COVID-19 pandemic, the accomplishments achieved throughout the multi-year availability are a testament to the dedication and perseverance of the project team and crew.

"The project team and ship’s crew came together throughout extraordinary circumstances to successfully complete Columbia’s complex availability at PHNSY & IMF," said Shipyard Commander Captain Greg Burton, "We are proud to return her to the fleet to once again patrol the seas supporting and defending free and open sea lanes around the world.”

Commissioned in 1995, Columbia was the last Los Angeles-class submarine built at Electric Boat Shipyard in Groton, Connecticut. Columbia is one of the most versatile weapons platforms ever placed in the world's oceans, capable of long-range Tomahawk strike operations, anti-submarine and surface shipping operations, surveillance and intelligence gathering, and special forces insertions. Columbia is currently assigned to Submarine Squadron 7 and homeported at the historic submarine piers in Pearl Harbor, Hawaii.

PHNSY & IMF is a field activity of NAVSEA and a one-stop regional maintenance center for the Navy’s surface ships and submarines. It is the largest industrial employer in the state of Hawaii, with a combined civilian and military workforce of approximately 6,400. It is the most comprehensive fleet repair and maintenance facility between the U.S. West Coast and the Far East, strategically located in the heart of the Pacific, being about a week’s steaming time closer to potential regional contingencies in the Indo-Pacific.