Prison Ship

A Prison Ship is a penitentiary, correctional facility, or jail that moves under its own power. Often featured to highlight the questionable practices of villains, the heroics of protagonist, a setting in itself, or just to move the story along. It's also an easy way to set up The Alcatraz; in the middle of the ocean or IN SPACE!, there's nowhere to escape to.

For the purposes of this trope there are two types of Prison Ship:
 * 1) the Prison Transport: often hijacked this humble vessel is either designed or modified to transport prisoners, not hold them permanently. The transport in Pitch Black is not a example as it had only one prisoner strapped in, the rest of the occupants were paying passengers. Conversely the prison transport in the Lexx miniseries would count because his divine shadow is just that thorough.
 * 2) The Jail: often a setting in and of itself this vessel is usually purpose built to hold prisoners permanently (often for unscrupulous deeds outside of jurisdiction) needs things like guard stations, plumbing, cafeteria, life-support, or stasis pods to function.

Anime

 * Cowboy Bebop episode "Black Dog Serenade". One such ship gets hijacked by prisoners.

Comic Books

 * The Marvel UK version of Zoids followed the story of the survivors of a human Prison Ship which crashed on what they think is an uninhabited planet but is in fact Zoidstar, former capital of the Zoidaryan Empire.
 * The Star Wars Expanded Universe had a "dungeon ship" which Luke found himself in in Dark Empire, specially-designed to hold Jedi.
 * Francois Bourgeon's series Les Passagers du vent contains both types at the time of the American War of Independence - a French slaver and a British prison hulk.
 * In Gotham City, Blackgate Prison (located on an island in the harbour) has used a modified barge as overflow housing for less dangerous prisoners. Cluemaster once planned a mass breakout that involved cutting the barge loose and having it picked up by modern-day pirate Cap'n Fear.

Film

 * The airplane in Con Air was a prison transport.
 * Von Ryan's Express is set on a train being used to transport allied POWs from Italy to Germany. The prisoners escape and hijack the train.
 * In X-Men: The Last Stand, the government imprisons Mystique in a special mobile prison built on a semi-trailer that is constantly moving; thereby making it harder for the Brotherhood to locate her and stage a rescue.
 * Amistad. The titular ship, a slaver, is a type 1.
 * One appears as a plot point in The Dark Knight.

Literature

 * In John W. Campbell's short story Who Goes There?, the characters speculated that the crashed alien vessel was a Prison Ship.
 * The Sherlock Holmes story The Adventure of the Gloria Scott concerns a prison ship to Australia.
 * Over the first few books in the X Wing Series we hear talk of Lusankya, the Empire's secret prison and brainwashing facility, but only later is it revealed to be the Lusankya, a Super Star Destroyer. Even after the pounding it takes in The Bacta War there's enough left to salvage, and the New Republic captures and makes use of it until the New Jedi Order, where it goes out in a proper blaze of glory for Operation Emperor's Spear.
 * Death Troopers largely takes place on one.
 * In Charles Dickens' Great Expectations, Abel Magwitch has escaped from a prison ship, and is transported to Australia on one.
 * The Matthew Hawkwood novel Rapscallion is set, in part, on the British prison hulks being used to hold POWs during the Napoleonic Wars.

Live Action TV

 * The original cast of Blakes Seven (with one exception, introduced later) were all prisoners on a Prison Ship.
 * Doctor Who episode "Doomsday". The Doctor discovers that the Genesis Ark was a Prison Ship built by the Time Lords during the Last Great Time War. Being of Time Lord origin, it's Bigger on the Inside and contains a small army of Daleks.
 * In Mirai Sentai Timeranger, the villains hijack a Prison Ship and name themselves after it.
 * Farscape: had many a episode set inside one, poignant considering Moya was one before the pilot episode.
 * A Stargate SG-1 episode centers on the team finding a crashed prison spaceship.
 * Both series of Battlestar Galactica had a prison ship among the ragtag fleet.
 * The Original Series had the Prison Barge, a ship used to hold prisoners of various kinds, including prisoners of war. Baltar organizes an escape from the ship along with various characters arrested or captured in previous episodes.
 * The Re-imagined Series had a prison ship called the Astral Queen which held common criminals as well as noted terrorist Tom Zarek. When the fleet needed laborers for dangerous duty mining water ice on a frozen moon, Zarek negotiated the partial release of the prisoners as a condition of their being used as grunt labor. The prisoners were given their former prison ship as their new home among the fleet.
 * On Red Dwarf, . Apparently only a few people are aware of that floor.
 * One episode of Star Trek: Enterprise had Captain Archer and Trip aboard one of these. The other criminals launched an escape and killed the guards, forcing them to make themselves useful to the criminals in order to survive.
 * An episode of Star Trek: Voyager had the Voyager itself briefly converted into a Prison Ship. Using Force Field Doors, of course...
 * The premise of Seven Days is the use of technology from the crashed Roswell UFO to develop Time Travel. In one episode, one of the inventors finally translates the markings on the ship and finds out that it is a prison transport. Unfortunately, the Grey prisoner has just escaped and is hell-bent on paying the humans back for putting him in a coma.

Real Life

 * Truth in Television, of course.

Tabletop RPG

 * Traveller Adventure 1 The Kinunir. The Kinunir class starship Gaesh was converted into a Prison Ship and used to hold Imperial political prisoners.
 * Warhammer 40,000's Imperium of Man has the dreaded Black Ships, each ferrying tens of thousands of psykers conscripted as per government policy. They're all taken to Holy Terra for processing, with the strong being "sanctioned" to serve as communicators or warriors, and the rest fed to a giant psychic navigational beacon.

Video Games

 * The Elder Scrolls III: Morrowind has you starting off in one.
 * Ratchet and Clank Going Commando has one.
 * Rayman 2: There's also The Buccaneer, the robot pirates' mobile headquarters and prison ship.
 * Unreal has you start out on a crashed prison transport named the "Vortex Rikers".
 * In Phantasy Star Online, an incarnation of Dark Force Faiz was locked away in a giant Prison Ship in the center of Ragol.
 * Mass Effect 2 has a sequence set on the prison ship Purgatory, a privately-run jail holding the type of prisoners planetary governments don't want in their prisons. The warden also makes some extra cash by threatening to release the inmates in the systems it passes through unless the locals cough up free supplies. Real nice guys, the Blue Suns.
 * And then the warden wants to imprison Shepard in order to make a buck. Shepard is supposed to be the hero, although there are plenty of enemies who'd like to see him/her out of the way (e.g. Shadow Broker, Collectors, Batarians, various gangs).
 * Though trying to imprison Shepard turned out to be a very bad idea.
 * An alternate Cave Johnson in the Portal 2 Perpetual Testing Initiative is captain of one of these.

Western Animation

 * An early episode of Avatar: The Last Airbender has a Fire Nation Prison Ship.
 * The X-Men animated series featured a two-part episode with a "Spirit-drinker" that Lady Deathstrike accidentally released from an alien Prison Ship.
 * Sherlock Holmes in the 22nd Century