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The Yangtze-31 (simply marked Yangtze in the game) is a submerged, barely functional Chinese submarine found in Fallout 4. When first discovered by the Sole Survivor in 2287, it is lodged in the shallow waters of Boston Harbor south of Boston Airport and northeast of the Four Leaf fishpacking plant.

The submarine is not marked on the map until the Sole Survivor swims out to it. Upon discovery, the quest Here There Be Monsters will automatically be started if it hasn't been received already from Donny Kowalski near the Shamrock Taphouse.


Yangtze-31 (Chinese: 揚子-三十一) is a Yangtze-class stealth submarine[Non-game 1] (referred to as Liao-class Type 113 in the game guide)[Non-game 2] of the Chinese People's Liberation Army Navy. It is a nuclear-powered ballistic missile submarine commanded by Captain Zao. Shortly before the Great War, the Yangtze was on deployment with a payload of six warheads, and an unknown number of tactical nuclear missiles and torpedoes. When the Great War began, the Yangtze's captain obeyed his orders to fire the submarine's strategic nuclear weapons at their targets. All but one of the missiles were successfully launched.[1]

Shortly after firing its strategic missiles, the Yangtze-31 struck a mine that severely damaged her reactor and forced her to seek shelter in Boston Harbor. The damage caused a reactor leak that immobilized the sub and ultimately killed or ghoulified the crew of approximately two dozen men, of which only Zao retained his sanity.[2][Non-game 2]


Unlike the only other Chinese submarine the player character can personally encounter in the series, SSN-37-1A, the Yangtze is a full-scale combat vessel with extensive crew amenities and visible missile and torpedo tubes.

The Yangtze has three large propellers, one on each side and a third under the reactor control room, as well as a smaller propeller at the rear of the submarine with the rudder. Upon entering the ship, the first room the Sole Survivor comes to is the bridge, where Zao is located. Down the stairs is the reactor control room, with a small radio room on the left side ahead.

North of the reactor room on the upper level is a small room that contains two decontamination showers and an Expert terminal-locked door with a stairway to the lower level. There is also a small science lab with a chemistry station. North of the crew quarters are two doorways that lead to a single stairway down into a room with a workshop containing a weapons workbench. The next room to the south is a small room before the reactor room, which contains a terminal-locked door to the stairway to the upper level.

Notable loot[]

  • Submariner uniform and submariner hat - Worn by Captain Zao.
  • Zao's sword - Possible reward for completing the quest. Only obtainable if all Speech checks are passed when first requesting a larger reward near the start of the quest.
  • Chinese officer sword - In the captain's quarters, on a desk.
  • Two fusion cores - One is in a box underwater on the east side of the lowest level of the engine room, just past a skeleton lying on a barrel. The other is inside an open footlocker in the crew quarters, near the Nuka-Cola Quantum.
  • Vault-Tec lunchbox - In the galley, on the table in the southeast corner.
  • Nuka-Cola Quantum and (closeby) Nuka-Cherry - In the crew quarters, next to the bunk of the dead crew member holding a Nuka-Cola truck.
  • Stealth Boy - In the armory, inside the Master terminal-locked cage.
  • Submariner hat - In the silo room, worn by the first mate, now a glowing one.
  • First mate's password - In the silo room, on the first mate.
  • Warhead - In the silo room, in the capsule on the west wall.
  • Hazmat suit - In the silo room, in a locker to the southeast. The door to the locker must first be manually opened to reveal the suit and other minor loot.

Related quests[]

  • Here There Be Monsters - Living on the ocean shorefront is a boy named Donny Kowalski, who asks the Sole Survivor to help him determine what he has been seeing out in the water recently.


  • Approximately 30 former crew members can be found, both alive and dead, throughout the submarine. Some are skeletons strewn throughout the ship, and some have been transformed into feral ghouls.
  • In the infirmary, the skeleton of an American serviceman is found on a bunk with handcuffs, with a bone cutter and a surgical scalpel on a table nearby.
  • The doors inside the submarine are called "bulkheads."
  • The Yangtze can be destroyed during the quest Here There Be Monsters when the Sole Survivor is tasked to replace the dampening coil and put a warhead in the reactor. However, the explosion will kill the Sole Survivor and Zao, even if they manage to leave the submarine before the explosion.
    • Even if the dampening coil and warhead are installed in the correct order, doing so before speaking with Zao will still cause the explosion because the reactor wasn't prepared first.
  • After completing the quest Here There Be Monsters, Travis reports that people have seen a submarine going out to sea. However, the Yangtze still doesn't actually move from its original position.
  • After completing the quest Here There Be Monsters, items can be safely stored in the ship.
  • The periscope/sensor mast of the Yangtze (confused for the eye of a monster by Donny Kowalski) is raised at times.
  • After using console command tmm 1 to reveal all locations on the map, the Yangtze location is not revealed.

Companion comments[]

  • When at this location, companions make comments, which are activated at three locations: the bridge, the engine room, and after placing the warhead in the reactor.
Location comments
Character Specific location Comment
Cait Bridge "Nothin' I'd rather do than spend my life underwater in a giant metal coffin."
Engine room "If you start tamperin' with that engine, I'm gettin' out of here."
After placing warhead "*Sigh* I hope you know what you're doin'."
Codsworth Bridge "Hmph. I suppose the red bastards deserve some credit for the state of this submarine."
Engine room "An impressive bit of machinery... for communist wankers."
After placing warhead "Sir/Mum, I do hope you know what you're doing helping this... captain."
Curie Bridge "The submarine, it is still working. Somewhat."
Engine room "I am no engineer, but the engines could be fixed, I think."
After placing warhead "Ah, look. It is working."
Danse Bridge "I'm only going to say this once. Don't touch anything. You turn the wrong valve, you could flood the entire vessel."
Engine room "I'm astounded that this vessel's nuclear power plant is still viable."
After placing warhead "I'm amazed you were able to get the engine to activate. Now all we have to do is hope that it remains stable."
Deacon Bridge "I can't believe it's still working."
Engine room "God, you Pre War types could do some amazing things."
After placing warhead "Woah. Hey, it's working. Damn."
Hancock Bridge "I'd love to not have to swim out of here, so maybe don't touch anything."
Engine room "That is some serious hardware."
After placing warhead "Damn. And folks lived down here listening to that?"
MacCready Bridge "This is great... I've always wanted to ride on one of these."
Engine room "Damn, that's a lot louder than I thought it would be."
After placing warhead "Unless you want to start glowing, you might want to hang back."
Nick Valentine Bridge "Well, it's certainly in better shape than I expected... thank god."
Engine room "Almost makes Diamond City's reactor look quaint."
After placing warhead "Imagine having to hear this all day long."
Piper Bridge "Oh, you've got to be kidding me. "Just one second. Need to get this all down.""
Engine room "Don't get to wander around an active submarine everyday."
After placing warhead "You know, it's kind of soothing once you go a little deaf."
Preston Garvey Bridge "I can't believe we're walking around inside a Chinese sub."
Engine room "I'd rather not get any closer to that than I have to. Just in case I want to have children one day."
After placing warhead "Well, what do you know. It actually worked."
X6-88 Bridge "This craft is remarkably well-preserved."
Engine room "If we ever need to disable this vessel, this is the place to do it."
After placing warhead "I admit it, I didn't think this would actually work."

Behind the scenes[]

  • The Yangtze-class is an unique, retrofuturistic shape not similar to any real-world submarine, unlike the SSN-37-1A, which bears a very conventional (albeit small) design. Its shape would give it a very conspicuous sonar profile.
  • While the Yangtze is tied to a single mission, Here There Be Monsters, the original design would see it take to the sea and crash into Vault 120 during 20 Leagues Under the Sea. Zao, its captain, would play a major role in the quest. Nothing remains of the quest, save for the cells in Fallout 76 files and a single marker in Fallout 4.
  • While Yangtze is a Chinese submarine and manned by a Chinese crew, her interior bears no Chinese characters (漢字, Hanzi). Warning signs are written in English, and the onboard terminals all use the RobCo Industries Unified Operating System. Furthermore, all other items present aboard seem to be of American origin, similar to the FMS Northern Star which is of Norwegian origin. Yangtze's design as also very similar to that of the American submarine USS Democracy from Far Harbor, albeit larger.
  • On page 507 in the Fallout 4 Vault Dweller's Survival Guide the class of the submarine is described as "Liao-Class Type 113"[Non-game 2] when it is actually a Yangtze-class.[3] However, in the real world, all People's Liberation Army Navy Submarine Force nuclear submarines are named Changzheng (Long March), followed by a serial number, i.e. "Changzheng-31." PLANSF submarines use types rather than classes, i.e. "Type-113." However, NATO assigns reporting names, also known as classes, to PLANSF submarines. These classes are based on Chinese dynasties, i.e. "Liao-class."
  • The Yangtze is the longest river in both Asia and China. However, in real life, the term Yangtze(揚子) is relatively unused in modern Chinese, apart from the river. Chinese speakers would likely use the much more popular term Changjiang(長江), while westerners use Yangtze. In addition, Yangtze would also have been spelled Yangzi in modern pinyin, since Yangtze is the romanized spelling.


The Yangtze appears only in Fallout 4.


Concept art and renders


  1. The Sole Survivor: "Where are you going to get that?"
    Zao: "Ah... Now that is the right question to ask. 200 years ago, I launched all of Yangtze's high-yield nuclear missiles. As ordered. For 200 years, I have lived with that guilt. That shame. So much fire Such bei. But one missile failed to launch. You must go down. Remove the warhead. Then bring it to me."
    (Zao's dialogue)
  2. The Sole Survivor: "Have you been here for 200 years?"
    Zao: "Wa! It has been that long? Shi de. Yes. I suppose it has. Long ago. Just after the fire. Yangtze struck a mine. My qianting barely made it here into harbor. City already ruins by then. Few noticed us. Fewer cared. Too much tong ku. Your arrival is good xingyun for me. I need help, you see. Yangtze is not... ahh... Seaworthy. You will help me fix her?"
    (Zao's dialogue)
  3. Yangtze-31 terminal entries; reactor terminal


  1. Josh Jay on ArtStation: "The Chinese stealth submarine in Boston Harbor that launched nuclear missiles against the mainland in Fallout 4."
  2. 2.0 2.1 2.2 Fallout 4 Vault Dweller's Survival Guide Collector's Edition p. 507: "[17.04] YANGTZE
    Easily mistaken for a strange aquatic monster, this Chinese nuclear submarine (Liao-Class Type 113) is hidden among the wrecks of other ships in the Boston Harbor. It is commanded by Captain Zao. Should you wish to access the terminal (Master) on the lower level, find the first mate’s password from the fellow lurking down in these parts."
    (Fallout 4 Vault Dweller's Survival Guide Map)