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For other uses, see Yamaguchi.

The USS Yamaguchi[2] (NCC-26510)[3] was a 24th century Federation starship, an Ambassador-class tier 4[4] heavy cruiser[5] in Starfleet service in the 24th and 25th[6] centuries. (DS9 episode: "Emissary", ST reference: The Star Trek Encyclopedia, Decipher RPG module: Starships, ST video game: Trexels mission: "Skirmish")

Due to a refit, the Yamaguchi became the prototype of its own subclass, the Yamaguchi-class tier 6 support cruiser. (STO - Klingon War mission: "Welcome to Earth Spacedock")


Around stardate 73XX.6, the Yamaguchi was rated a level 4 battle group heavy cruiser. It featured room for four officers and slots for five weapons or additional systems. Its deflector shields were rated 490, while the structural integrity field, or hull strength, topped at 645. (ST video game: Trexels mission: "Skirmish")

At some point during the 24th century, Yamaguchi's spaceframe was modified, and the ship became the lead vessel of the the Yamaguchi-class tier 6 support cruiser and fleet support cruiser variants. The upgrades included a different positioning of the connection between saucer section and the neck of the engineering hull, shorter nacelle pylons, and an additional shuttlebay underneath the original bay. (STO - Klingon War mission: "Welcome to Earth Spacedock")


24th century[]

The Yamaguchi was launched in 2342. (ST reference: The Autobiography of Jean-Luc Picard)

On stardate 44002.3 in the year 2367, the Yamaguchi was part of the Federation fleet that engaged the Borg in the Battle of Wolf 359. The Yamaguchi joined the wave that included the USS Bellerophon. The Yamaguchi was badly damaged in the battle and considered destroyed.[6] (DS9 episode: "Emissary")

Years later, after having been rebuilt, the Yamaguchi fought in the Dominion War with the Twelfth Fleet. In 2375, she successfully breached the Dominion line in the Battle of Betazed. (Decipher RPG module: Starships)

As part of Federation Starfleet operations in the Trexelian Expanse around stardate 73XX.6, the USS Yamaguchi participated in the war games conducted by Starfleet and allied vessels from the 23rd and 24th centuries. (ST video game: Trexels mission: "Skirmish")

The Yamaguchi also saw action in conflicts with the Klingon Empire, Cardassian Union and Breen Confederacy. (ST video game: Trexels missions: "Events", "Breen Barrier")

25th century[]

In 2410, the Yamaguchi-class was designated a tier 6 support cruiser, and the Yamaguchi itself was chosen as the class representative in the Starfleet Shipyards Operations interface. (STO - Klingon War mission: "Welcome to Earth Spacedock")

In that year, the Yamaguchi was docked inside Earth Spacedock. (STO - Legacy of Romulus mission: "Welcome to Earth Spacedock")

Following the Battle of Excalbia on stardate 84999.22[7] in January 2411, which saw the prominent involvement of hero ships from the Federation's past and present, several Federation later other Khitomer Alliance ships underwent a refit to legendary starship[8] qualifications. (STO - J'Ula's Discovery missions: "Measure of Morality (Part 2)", "Welcome to Earth Spacedock")

Legendary temporal support cruisers.

The USS Yamaguchi, USS Narendra and a replica of the USS Enterprise-C received upgrades in the year 2411, shortly after the Shattering of the Klingon Empire during the Klingon Civil War of 2411. The ships then performed maneuvers in orbit of a planet. (STO website: Updates to the Ambassador and Narendra)

After the return of Klingon Chancellor L'Rell[9], the Yamaguchi was among the support cruiser ships that Starfleet refitted to legendary starship standards. The USS Yamaguchi, the replica USS Enterprise-C, the USS Narendra were upgraded to match the capabilities of the newly launched legendary temporal support cruiser USS Horatio. (STO website: The Legendary Temporal Support Cruiser)



Ambassador-class explorer/heavy cruiser starships
Federation Starfleet
(primary universe)
standard configuration AdelphiAmbassadorAssuranceAuroraAyersChamplinCrescentCybeleEnterprise-CExcaliburExeterFuryGandhiGravinaHammarskjöldHannibalHardingHawkesburyHickokHoratioIndependenceIndianapolisIroquoisIsisKadoscaKrotusLoma PrietaMacDonaldMadisonManassasMonroeMontgomeryNormanQuiberonSeattleSheltonStrongThelianThornValdemarVelascoWarakurnaWilsonWinslowYamaguchiZarnitzaZhukov Emblem of the United Federation of Planets. Seal of the Federation Starfleet.
variant configurations Horatio-subclass: HoratioNarendra-subclass: NarendraYamaguchi-subclass: ExcaliburForrestalYamaguchiZhukov
Terran Imperial Starfleet
(mirror universe)
Horatiovariant configurations: Ambassador Seal of the Terran Empire icon image.
Ships at the Battle of Wolf 359
Federation, Starfleet USS AhwahneeUSS BellerophonUSS BonestellUSS BuranUSS ChekovUSS EndeavourUSS FirebrandUSS GageUSS HoaglandUSS KadoscaUSS KyushuUSS LiberatorUSS Melbourne (Excelsior-class)USS Melbourne (Nebula-class)USS PorksauceUSS PrincetonUSS RighteousUSS RooseveltUSS SaratogaUSS Star LeagueUSS TolstoyUSS VictoryUSS YamaguchiUSS Yorktownunnamed Constitution class starshipsunnamed Nova class starships UFP emblem image. Emblem of Starfleet.
Borg Collective Cube 632 (Locutus's cube) Borg emblem.


External links[]