U.S. Navy completes overhaul extending service life of nuclear-powered submarine USS Cheyenne

The submarine underwent the works at the federal Portsmouth Naval Shipyard in Kittery, Maine, at a cost of USD 315 million, with the process lasting from November 2021. In addition to a standard overhaul and replacement of reactor fuel rods, the programme included a life-extension review exceeding the originally planned 44 years of service.

According to the Department of War, the modernisation covered the sonar system and the command and combat control system, both using technologies applied on newer Virginia-class submarines, as well as a review of the electrical installation. Crew living spaces were also rebuilt as part of the upgrade, which is the most extensive ever carried out on a submarine of this type.

USS Cheyenne is the last nuclear-powered attack submarine of the Los Angeles-class submarines, built by Newport News Shipbuilding and commissioned on 13 September 1996. Publicly released data indicate that seven submarines of this class are to undergo similar life-extension and modernisation processes, although no detailed list has yet been published.