Crew of One

"Blackadder: I was under the impression that it was common maritime practice for a ship to have a crew. Redbeard Rum: Opinion is divided on the subject: All the other captains say it is, I say it isn't!"

- Blackadder

Several kinds of vehicles are so complex and require such multitasking that they cannot be operated by a single person: tanks, trains, certain airplanes, etc.

Take the typical tank, for example. If you're in the driver's seat, you have limited visibility and you can't load or fire the main gun. If you're in the commanders seat, you can see all around you, but you can't drive, shoot or load the gun. If you're in the loader's seat, you can't see well or drive (you might not even be able to shoot the main gun).

However, this doesn't seem to be a problem in Fictionland. The Hero (usually a Universal Driver's License holder) can easily handle any such vehicle singlehandedly. Common in certain movies and video games (though in the latter case it could be considered an acceptable break from reality)

Almost universal in the case of Humongous Mecha, the notable exceptions being Combiners.

This can be justified in certain Speculative Fiction settings by omnipresent computers and simple AI. One might say the ideal number of people for any given vehicle is one: one human to handle the tactics and the moral decisions, and computers to handle the rest of the more mechanical tasks like navigation. The limiting factors, of course, are the amount of multitasking still left to the pilot, and how long the pilot can function at that level.

It can also be justified in emergency situations, at least in aviation. In the case of the death or incapacitation of one member of the flight crew, for instance, the other pilot is always able to fly the aircraft. In fact, it's a requirement that all aircraft be flyable by a single pilot for this very reason. And it's not that rare a circumstance; dozens of pilots have died during flight.

Compare Guy in Back and how they are often treated in video games.

Naval Vehicles
"Bart: Think he's going to do something dangerous? Nelson:How should I know? Just keep loading missiles. [loads one into a launcher] Ralph:[carrying a missile] Pop music's hard work."
 * Parodied in the climax of The Simpsons episode "New Kids on The Bleech", where pop band manager/Navy Lieutenant L.T. Smash single-handedly hijacks an aircraft carrier. Well...almost single-handedly:


 * While you can't quite pilot a battleship or aircraft carrier by yourself in the Battlefield series, you can instantaneously hop between a ship's four to six different stations with a keypress to come remarkably close.
 * The Protoss Carrier in Starcraft is, as the name implies, an aircraft carrier that can carry eight additional fighters inside, all helmed and controlled apparently by ONE Protoss. With his mind, no less. The fighter are supposedly mostly autonomous robot vehicles which receive targeting information and group launch/recall orders from their carrier (and manufacturing factory), making this a bit more plausible.
 * Despite the above quote, this trope is subverted in Pirates of the Caribbean. Jack and Will only manage to pilot the Interceptor after Norrington and his men set the sails. Even then, Jack admits that he can't sail it by himself.
 * But then in the sequel, they say that you could crew the Black Pearl with six men. That ship is huge. Do you know how heavy those sails are?
 * To be fair, they never said they could pilot it WELL...
 * Specifically, the debate was about the absolute minimum number of crew that the Pearl needed.
 * Blackadder II features the batshit insane Cpt. Rum, who runs a ship without a crew. Granted, he usually cons passengers by 'sailing 'round and 'round the Isle of Wight 'til everyone gets dizzy' then sailing home.
 * In Battlefield 1942, a single player could seize control of an naval ship and sail it around. There was almost zero reason to do this. Aside from one reason.
 * Single-handed oceanic sailing in the Real Life. The first transatlantic single-handed crossing must have occurred already in the 18th century. First person to sail single-handedly around the world was Joshua Slocum in 1895-1898 on his two-masted 36'9" ketch Spray. This feat has been repeated several times.

Tanks
In games tanks and other AFVs are by far the outstanding demonstrator of this trope; more often than not, a single person will be able to drive, aim, and fire the main weapons of an armoured vehicles on their own. Games which involve having multiple players operating one vehicle will usually have one player driving and any others operating the vehicle's weapons systems. It is also very rare to get a real first-person view inside the tank, usually to avoid showing the crew working but also because this is usually not conducive to gameplay. The rest is a Rule of Fun issue; it's rather hard to get people excited about getting to be a tank's loader or radio operator.


 * Mercenaries (The game, not Private Military Contractors)
 * Oddly, it's not allowed when driving the smaller vehicles. That missile launcher on your converted pickup will sit there and look adorable until you convince an ally to crew the bloody thing. And at least they make you run up and drop a grenade in a tank's crew hatch before 'borrowing' the whole thing.
 * Crysis has tanks, as well as jeeps and trucks, whose mounted weapons are controllable from the driver's seat. They just magically swing around. Note that this happens only in easy difficulty; harder difficulty levels require you to change seat in order to control the gun - although that still takes such a short time that it isn't really much of a hinderance.
 * Note that, on the higher difficulties, you can still drive the tank and aim/fire the main cannon at the same time.
 * In Call of Duty 2 the player is in control of all of the tank's functions, but it is understood that the tank has a proper crew.
 * The same is true of the original Call of Duty's brief tank segment. The Hand Wave is that you're the tank commander, and this is gameplay shorthand for you playing spotter and telling the crew what to do.
 * The Commandos series averts this, at least with tanks -- the Driver can drive tanks, but the Sapper must be on-board to fire the cannon.
 * The Battlefield series.
 * Some vehicles (such as the BTR-60 in Battlefield Vietnam) were in fact kinda useless without two people, one to drive and one to shoot. Other vehicles, such as the helicopters in Battlefield Vietnam and Battlefield 2 became significantly more effective with a second crewman to fire more guns, but didn't necessarily require them. But the tanks were pretty much always one-crew killing machines.
 * The Grand Theft Auto series.
 * The Command & Conquer franchise has plenty of variations.
 * Renegade, in all its gameplay simplicity, although one can set the game so when a second character embarks, he's the gunner. But not only is it optional, it's never enabled on any server. There is nothing to stop you from operating a Mammoth Tank all by yourself.
 * Tiberian Dawn originated C&C's surviving crew concept, where there is a fifty-fifty chance that a single soldier will pop out of a destroyed land vehicle. Red Alert extended the concept to aircraft. Then came Tiberian Sun, and suddenly, you have special hijackers. The idea only went as far as that before it was dummied out in Red Alert 2.
 * Generals made it possible to neutralize vehicle crews and take over the vehicle by ordering a single infantry unit into it. And they all know how to drive anything, too.
 * But only American vehicles have the ability to eject a soldier out of their machines and in spirit of the C&C games before it, only eject one soldier per vehicle. But it's not just any soldier, either; it's a trained Pilot, and for very good reason, too: a Pilot carries his experience with him. If he manages to get onto a friendly vehicle, he'll pass his battle experience down to the crew riding that vehicle.
 * The Landmaster in Star FOX. Probably justified due to the advanced tech of the races in the Lylat system.
 * This one does seems to be hardly larger than an Arwing (at most), and just about as complex.
 * The entire Halo series - mostly. Several vehicles can be run by Master Chief alone, including the Scorpion Tank, while a number of other ones have a gunner's seat as well.
 * In the fluff for the game it's explicitly stated that a Scorpion can be operated by two Marines OR a single Spartan.
 * A Spartan can't operate the gun on a Warthog jeep and drive it at the same time. This is justified in that the gun controls are physically located in a different part of the vehicle.
 * In XXX 2: State Of The Union: Darius' single handed operation of the tank stretches believability, it does look more awkward than his pursuers (fully staffed tanks) but it is his first time.
 * Golden Eye 1997 does this with a tank in the second level, not to mention a similar tank in the original film. Plus numerous other vehicles throughout the series.
 * Though in the film, he mostly just drives the tank, with apparently limited manoeverability. When he does fire it, it is completely stationary (implying that he moved about in it) and is being fired at an oncoming train.
 * Behind the scenes, Brosnan wasn't controlling the tank, just sticking his head through the front hatch. The real driver was lying prone on the floor underneath him and looking though a concealed glass panel cut out of the glacis plate.
 * Rambo does this in Rambo III. He's apparently able to drive, fire and load a Soviet tank with his head sticking out the front hatch.
 * Taken to spectacular heights in Keith Laumer's Bolo series, where massive continent-sieging combat vehicles can be operated by a single pilot. Some of the later models, however, don't even need a pilot at all.
 * Though supposedly not artificially intelligent, one Bolo mk III demonstrates the ability to operate entirely without human control. Most Bolo stories feature mk XV or higher units that have no real need of human crew, though almost all marks are intended to carry a commander.
 * In PlanetSide the factions' main battle tanks, along with jeeps, bombers, and transport vehicles, generally need at least one other player to man the guns, with the vehicle having to be stopped and a fair amount of motion needed to change slots. However, the Lightning skirmish tank and the Basilisk and Fury all-terrain vehicles used this trope to be the game's only real single-person ground combat vehicles.
 * Many old arcade shooters, when the player gets a tank, would let him crew it himself. Front Line and Ikari Warriors come to mind.
 * Metal Slug, on the other hand, does not count, given that the tank in question is too small for a second driver/gunner anyway.
 * Tokyo Wars is another example.
 * Real-Life example: When a crazy man stole a tank from a San Diego National Guard base and began rampaging around, the news anchors describing the action had to repeatedly remind the viewers that he could not operate the main gun alone.
 * In the original Mobile Suit Gundam, while not all tanks can be run by one man, the crew sizes are unrealistically small. The Federation's Type 61 tank has only a driver & a gunner, with the commanding officer usually taking the latter station, possibly justified by panoramic view provided by tiny cameras on the hull & screens in the interior. The Guntank also starts out with a driver/gunner crew, but is later upgraded so it can be piloted singlehandedly. The Zeon Magella Attack Tank, on the other hand plays it straight, with a single pilot in the turret, which can detach & become a fighter jet.
 * Annoyingly inconsistent in Medal of Honor: Allied Assault. Stealing an enemy tank in the original game requires escorting a specially trained crew to the tank, but in the Spearhead expansion, you manage to singlehandedly operate a tank after fighting your way deep into Berlin.
 * In Warhawk (1995 video game), tanks need only one player to be both driver and main gunner. A second player can board the tank and fire weapons from its hatch, or preferably, keep it repaired with the Wrench.
 * A 4x4 driver on the other hand, can only drive and honk the horn. It takes a second player on the 4x4 to fire its machine gun.
 * Utterly averted in Operation Flashpoint, in which tanks have the full crew of three (driver, gunner, and commander), though you can do without a commander in a pinch (and suffer impaired visibility as a result). In the tank missions the player typically acts as a tank commander, giving movement orders to the driver and targeting and firing orders to the gunner over the radio. If the tank isn't operating with a full crew, the ones present can switch positions as needed; even one person can drive a tank provided he switches between driving and aiming/firing as needed.
 * Also averted for the other types of vehicles in OFP. Boats, helicopters, and even armed jeeps have a separate driver and gunner. In all cases, the driver can still fire (though not aim) the weapons in the absence of a gunner.
 * Helicopters and tanks can switch to "manual mode" where the pilot/commander handles firing weapons all by himself but tanks still need targeting orders for the gunner, the commander can't do that himself.
 * Every vehicle in Battlezone 1998, most of which are hovertanks of one form or another. The player can even snipe the driver of an enemy tank, run over and jump in. Even if said tank is explicity stated to be an AI-controlled drone.
 * Averted in the old Sony online shooter Infantry. All the large vehicles required a driver and a gunner for each weapon the vehicle had. IIRC this meant that the hovertank required 4 players to be fully effective: one driver, one main gunner and two machine gunners.
 * Space Marine tanks in Warhammer 40000 have very small crew sizes: typically just a driver/commander and a single gunner, with advanced "machine spirits" taking care of jobs that would normally go to other crewmen. (Chaos Space Marine vehicles are much the same, but instead of machine spirits, they have daemons.) The Imperial Guard, who possess more men and less impressive technology than the Marines, have tanks with more conventional crew sizes.
 * In Valkyria Chronicles it's implied that the crew of the Edelweiss consists of just Welkin and Isara. The Edelweiss is based on a King Tiger, with five crew positions; it even conspicuously has an access hatch for the radio operator it apparently doesn't have. Later entries sometimes only have a single named person for an entire vehicle.
 * The MMO World of Tanks lives and breathes this trope, while simultaneously averting it. The player can control a tank, a tank destroyer, or a self propelled gun entirely with the mouse and a few keyboard hotkeys, but NPC crewmembers represent the commander, loader, gunner, radio operator, driver, and so on.
 * Averted in Unreal Tournament with several vehicles, all of which need a full crew to man all the guns.
 * The Goliath, the Cicada and the SPMA has the driver handling movement and the main weapon at the same time, with the second crew member manning a secondary weapon (top-mounted machine gun for the Goliath, gimbal laser turret and flares for the Cicada, skymine launcher for the SPMA).
 * The Hellbender has a driver, one gunner shooting a skymine launcher and another gunner manning a back-mounted laser turret. Surprisingly, this actually has a purpose as the rear gunner is completely exposed and vulnerable to snipers while the other gunner is even harder to snipe than the driver. The driver himself can do nothing but hoot; on the other hand, the bots in 2004 are scripted to automatically board a hooting Hellbender.
 * The Leviathan has not one but FOUR secondary positions, each handling a separate turret. As with the trio above, the Leviathan's driver also handles both main weapons.
 * The World War 2 game Red Orchestra: Ostfront 41-45 may be one of the few video games to nearly subvert this. There is a driver, main gun, and machine gun position on a tank; the driver can't see, and the gunners can't move. A good team needs to have the two coordinating their actions during a tank fight. Nearly, because players can and will drive out on their own, and switch between positions as needed.
 * Stated in the Earth 2150 manual that Eurasian Dynasty's tanks are, essentially, late 20th century tanks that have been refitted to be piloted by a single cyborg.

Spaceships

 * The Andromeda Ascendant is a kilometer-long capital ship with dozens of slipfighters and relativistic missile launchers and for most of the series functions with a crew of six. Albeit justified as most of the original crew of thousands abandoned ship in the pilot and the AI is capable of filling most of their functions.
 * Played with in Doctor Who: the Doctor's frantic dashing from one control to another while driving the TARDIS led many to theorize that it wasn't designed to be operated by a single Time Lord (though The Doctor does manage it pretty well. Most of the time.) This was confirmed in the commentary of one episode of the first series: The Doctor's TARDIS was designed to have 6 operators.
 * This can be surmised by the fact the control console is hexagonal indicating 6 duty stations.
 * There's also the fact that when you consider how many times the TARDIS malfunctions or is otherwise inaccurate in arriving at its destination, it seems that the Doctor is just barely able to maintain the thing. It is also occasionally implied that even he is not quite sure how it works, and leaves a certain degree of its operation to chance or trial and error. It helps that this particular TARDIS was a banged-up, obsolete model when the Doctor originally stole it.
 * The original set designer of the TARDIS said that he put all the controls and gauges on a control panel in the center of the room because one person was operating it.
 * Martian Successor Nadesico's movie shows the humans' One-Man One-Ship project attempting to engineer a human that could handle a ship all by himself, with onscreen results in the form of Ruri (a Super Prototype?), Harry, and Lapis.
 * Most games from the X-Universe series allow you to fly capital spaceships the size of space stations entirely on your own. Made all the more ridiculous because the ships in question are very clearly meant to house other people (at least, the lights and windows all over their surface suggest so). Handwaved by having the ship's computer handle practically everything. However, AI controlled capital ships (and corvettes) all have a large crew when open a comm channel with them - such as the Captain and navigation officer.
 * In X2: The Threat, this is very obvious by the lack of crewmen at your bridge's seats.
 * At the same time, Not only is the player controlling their own ship, but also the many many ships of their empire at the same time. (Although these too are computer controlled, the "living" NPC pilots aren't much smarter than your AI-controlled ships.)
 * General fan consensus is that the ships are manned, just by invisible Player Mooks.
 * The cargo freighters in Freelancer. Partly justified because they come across as trailer trucks
 * Also, although capital ships are implied to have a full crew, there's several third party mod where you can pilot one of these by yourself.
 * Spacecraft in EVE Online can be controlled by a single person, assuming that said single person is a 'capsuleer', or 'pod pilot' and the ship is designed to accept a pod. Otherwise it takes a full crew to fly a ship. Only a small fraction of humanity has the potential to be pod pilots, and those people are considered a valuable resource, to the point that capsuleers are assured access to clones and that no empire can lay claim to them.
 * It's assumed by the EVE-Online community that even capsuleer ships have some crew (1-6 for frigates, thousands for a battleship) but they're invisible because Life is Cheap in the Eve 'verse.
 * Assumed my foot. EVE Online is an aversion, except possibly in the case of the Reaper, which thematically is so small it barely escapes getting classified as a two-man fighter without a capsule. The question of crew presence has long been answered; they're just smaller than in non-capsuleer craft (and still generally huge). The question of late is if the crew should have any sort of in-system representation.
 * Derek Smart's Battlecruiser 3000AD series is this trope taken to the ridiculous extreme. Of course, in-universe, there are crews, but it's actually one man, the player, doing EVERYTHING.
 * In GURPS there are two ways to do this with spaceships. Either you can have an AI automate the system or you can take a penalty to skill rolls for multitasking, in fact with a big enough penalty it's possible for one person without any "superpowers" to run a ship that normally has a bridge crew of 60 people.
 * In Alastair Reynolds Revelation Space 'verse, the extreme size of the lighthuggers (around 4 kilometres long in most cases) are often contrasted with their relatively tiny crews; in Galactic North, the story revolves around two such ships that are crewed by single people. In his unconnected story House of Suns, each shatterling is given his or her own starship and expected to go it alone, minus the odd passenger.
 * Any brainship in Anne McCaffrey's The Ship Who series could technically run with just the shellperson controlling it -- just one person. However, these ships are usually paired with a normal human, resulting in a crew of two.
 * The Brawn is there for maintenance, cargo handling, company, and remote operations.
 * A Star Trek novel has Scotty control an entire starship himself by basically rigging a shuttlecraft's controls into it, so that the ship basically does whatever you tell the shuttle to do. Of course, he is Scotty.
 * Star Trek spaceships (at least of the Star Trek the Next Generation era) can generally be operated by a single person thanks to the advanced computers (though maintenance requires a complete crew).
 * In Star Trek III the Search For Spock, Scotty automates the Enterprise sufficiently to fly it with only a few people... though the system breaks down when they end up in a combat situation.
 * Taken to the extreme by the USS Prometheus in Voyager, which is advanced enough to fly a complete combat mission against Romulans - and win - without any crew at all (there were two characters on board, but they weren't actually piloting it). Somehow it still manages to avoid being classed as an AI, however.
 * Subverted in one episode of Star Trek the Next Generation when this is one more reason Beverly Crusher realizes something is HORRIBLY WRONG when only she and Picard are piloting the Enterprise. She asks him why there is no crew and he responds 'We never needed anyone else.'
 * ''Stargate SG-1': while an early appearance by an Asgard ship has Thor refer to having evacuated his crew when the ship was overrun, later appearances seem to imply it's just him aboard. He's certainly able to operate all its functions without even leaving his chair.
 * This is most likely the same situation as In Star Trek above: Automation allows a single person to operate the ship (although possibly not as well as a full crew), but maintenance is impossible. There is no sign of anything like maintenance bots, for instance.
 * In Mass Effect 2, the Cerberus-built Normandy includes an AI that could theoretically take over pretty much every aspect of running the ship, apart from helming it, and allow it to be run by a crew of one. Cerberus intentionally made the AI unable to do so,, and thus the ship features a full human crew complement.
 * Various ships in the Star Wars Expanded Universe have large crew complements which for one reason or another end up being cut down.
 * The Courtship of Princess Leia has Luke Skywalker flying the Falcon - whose unmodified version is supposed to be controlled by at least three people with another two at the guns, but has been altered extensively - and using the Force to operate all of the controls, including the turbolasers, with extreme precision.
 * In Wraith Squadron, the titular twelve-member squadron manages to capture a modified Corellian corvette and immediately call for crewers. They crew it themselves until the New Republic sends more people, but have some difficulty.
 * In The Thrawn Trilogy it's a plot point. Dreadnaught-class heavy cruisers usually need a crew complement of sixteen thousand people, but one fleet - called the Katana Fleet or the Dark Force - was fitted with slave circuitry which reduced the needed crew to two thousand two hundred each. And meant that when the crewers on the flagship caught a hive virus, went insane, and programmed a random jump, the entire fleet was lost in the depths of interstellar space, at least until they were accidentally found many years later.
 * Most starships in the later years of Known Space history are computer-automated to the point that a single pilot is all the crew you need. Of course, the cruise ships, military vessels, and exploration craft all carry larger crews for other reasons (guest comfort, backup in case of death or injury, and so on), but they don't need to if all they want to do is get from Planet A to Planet B.
 * It is perfectly possible for the autopilot to do ALMOST the entire flight, except for one minor detail: Traveling too close to a massive body while in hyperspace will destroy the ship, and a mass sensor, the only system capable to detecting such a hazard while in hyperspace, is a psionic device. That is, it operates only because a mind is examining the output.
 * In Path of the Fury, there is exactly one kind of interstellar spacecraft capable of being crewed by a single person, and that is the alpha synth. Even small courier vessels or heavily automated larger vessels generally require a crew of at least six.
 * Battlestar Galactica Online: You can take command of starships that should need multiple crewmen, but no mention of those is ever made.
 * Elite has one player piloting the ship and there are no mentions of the crew...
 * In Frontier versions the player character have to hire extra crew (number varies with ship type). Then again, fighters and small delivery craft have crew of 1 and others don't need all that much, even the huge ones - Imperial Explorer requires only 10, Griffin and Panther 12. At the rates crew is available for hire, sitting at a base and checking its message board until you get all 11 may take some time even at a high time scale, but if you can afford such a ship, you can afford to pay your early hires while waiting for the rest, too.
 * In Frontier versions the player character have to hire extra crew (number varies with ship type). Then again, fighters and small delivery craft have crew of 1 and others don't need all that much, even the huge ones - Imperial Explorer requires only 10, Griffin and Panther 12. At the rates crew is available for hire, sitting at a base and checking its message board until you get all 11 may take some time even at a high time scale, but if you can afford such a ship, you can afford to pay your early hires while waiting for the rest, too.

Other

 * Adverted in the MMO-FPS World War Two Online. More of a Simulator than a true FPS, driving tanks and boats required multiple crew members for multiple respective positions; The driver is, in fact, unable to shoot, has poor viability, etc. The player can swap between positions easy, however, but that doesn't lend much good in battle when one well-aimed shell can take you out.
 * Lampshaded in Armored Core: For Answer. The megacorporations in the game world used to rely on Humongous Mecha which played this trope straight, until they figured out that it was too dangerous to leave that kind of firepower in the hands of a single pilot. Consequently they started building Military Mashup Machines with hundreds of crew instead.
 * The video game Megafortress illustrated this literally - there are several different stations all simulated (pilot, weapons officer, EW officer, etc), but it's up to the player to hop around to all the stations to control them. This can be tricky when you're trying to turn around to bring some weaponry to bear while firing a missile at the MiG heading at you while trying to get the bomb bay doors closed and fiddle the ECM settings. Never mind the engine that's on fire from the last hit and the fact your attack radar is still on, broadcasting your position to the world.
 * Several vehicles in the Star Wars Battlefront games have multiple crew slots. The Assault Gunship has five: pilot, copilot, left, right & tail gunners. Only a pilot is required to drive and fire the main weapons, but a solo operator can switch rapidly from slot to slot if he wants to.
 * Taken to an extreme with the snowspeeders from the Hoth map: in the first Battlefront, a single player can fly one towards the Empire's AT-AT's, switch to the rear turret, fire the cable at its legs, then immediately switch back to the pilot's seat and tie it up. Quite understandably, Battlefront II added a forced delay between firing the cable and switching seats, making it nearly impossible to take an AT-AT down that way without two people.
 * Airplane!!: Ted Striker flies a modern jet airliner by himself, a task that normally takes a crew of three (pilot, co-pilot, flight engineer).
 * The film sort of hangs a lampshade on this with what confronts Striker when he first enters the cockpit: a slow pan across a literally endless array of dials, levers, switches and knobs. The Boeing 707 seen (but not heard) in the movie can be flown for a short time with a crew of one (the pilot). For longer flights, you need a flight engineer to keep an eye on the airplane's mechanical systems, and if you want to reach your destination, you add a third: the navigator. Modern jetliners only need a crew of two, the flight engineer's position having been given to computers.
 * It's long been a standing joke in the airline industry that the flight crew will soon be reduced to just a man and a dog. The man will be there to feed the dog, and the dog will be there to bite the man if he tries to touch the controls (though one has to ask what kind of dog would (literally) bite the hand that feeds it).
 * There were real-life attempts to create one-man armored fighting vehicles back during the 1920s and 1930s; they belonged to a class of vehicles known as "tankettes." The French, for example, wanted to create a sort of infantry replacement; one man would drive the vehicle and take care of everything, and he'd also be armed with a machine gun. In practice, it was unworkable, and the concept was abandoned. To be perfectly fair, during the past century there has been a significant trend towards smaller crew sizes, due primarily to automation.
 * However, the minimum crew size in a turreted vehicle is still three, because the only crewman who can realistically be replaced is the loader. And most western armies have avoided autoloaders because a good human loader is much more reliable, faster and more flexible. An autoloader can't help change a track, pull maintenance, stand guard, or sub for another crewman, either. He also serves as an extra pair of eyes to watch your back when he isn't loading.
 * Furthermore, reducing the crew to just one is probably inadvisable simply for morale reasons.
 * The titular Humongous Mecha in Metal Armor Dragonar require high-powered AI to aid in operation in order to keep the crew size down to a single person.
 * In the Ace Combat series, when you choose any aircraft with a crew of 2 or more (F-15E, F/A-18F, F-14, etc...), you still control all of its functions yourself as if it only needed one person...however, when you look at the actual plane's MODEL, you can see a guy in the back seat, presumably doing his job alongside the pilot.
 * Airforce Delta Strike does this for its 2-man fighters as well.
 * As does HAWX, though for at least one mission in the first game the guy in back is actually acknowledged (he's the one training you in the game's main gimmick).
 * In World of Warcraft the Catapults used during Wintergrasp fights have space for only one driver/gunner. The Demolishers also has a driver/gunner but have space for two passengers who can fire their own ranged weapons (bows, guns, etc.) from their seats. The Siege Engines have a ram controlled by the driver, a turret-mounted cannon that requires a separate gunner and two passenger spots. Similar vehicles exist on the Isle of Conquest, Ulduar and other in-game locations.
 * Prototype. While Alex has learned how to pilot APCs, tanks and helicopters by consuming people trained to do so, he can somehow operate them all by himself.
 * Maybe with his tentacles?
 * Come to think of it, this guy has the ability to shapeshift into basically anything...it is not a far stretch to assume he just fills the entire vehicle with himself and can then easily operate all the switches, buttons and levers as he pleases.
 * Inverted on Top Gear: In a crossover challenge with German motoring show D Motor, the presenters had to drive double-decker cars, with one person on top steering and a second person on the bottom operating the pedals and gearshift, thus turning a vehicle that normally is Crew Of One into Crew Of Two.
 * Trains can run with a Crew of One, it's called DOO (Driver Only Operation).
 * Real Life Subversion: Docklands Light Railway runs trains with a crew of nought.
 * Though the on-board Passenger Service Agent is trained to become the Crew of One and drive the train if computer operation fails.
 * Both used and averted in Assassin's Creed Brotherhood. The  is justified as only having enough space for one man. The   needs three people to run it, though gameplay usage does not act as such. The   is clearly meant to have a driver and gunner, but you get separate parts of the mission for using both and during the latter the thing is on autopilot or something. The   clearly is meant to have a gunner and driver too and this time Ezio has to switch between the two positions as necessary.
 * Almost all fighter aircraft have a one-man crew, who both flies the aircraft and operates the weapons.
 * Many exceptions to this are electronic-warfare variants of what are otherwise single-seat fighters (themselves often based on a two-seat trainer variant). The second person runs the (much more extensive) electronic warfare equipment. There are also fighters that only exist in two-seat configurations, which often carry much more elaborate electronics packages than single-seat aircraft do (since there's another person there to operate the more complex systems), such as the F-14 and A-6.
 * Can be seen in Half-Life 2 with both dune buggy and air boat. Being piloted by one fellow is reasonable enough, but that same fellow being a simultaneous driver and gunner? Not so much. Multitasking capabilities aside, there is a certain minimum of available arms required to preform both tasks, which can lead to only one conclusion :Gordon Freeman has an extra set of invisible hands. This would also explain how he can climb a ladder while fully operating a gun. Then again, maybe he has three sets of hands, two of which invisible, as his arms aren't visible while driving either vehicle.
 * Well, he can pick up objects without using his hands.
 * Averted by ALL multi-crew vehicles in the Tribes games, Even the Hover Tank has a driver and gunner, to say nothing of the larger aircraft where there is always a pilot who only handles flight and a tailgunner whose main duty is chucking flares at incoming missiles. Bombers have a weapons officer to handle the onboard ordnance and gunships have four passenger slots whose occupants can use their own infantry weapons to rain Death From Above; a single-man gunship is just a big fat target but a fully loaded one with everyone sans the pilot wielding mortars and missile launchers is a flying fortress. If you want to switch positions, you have to physically disembark the vehicle first.
 * An example from Real Life. Sterling Marlin became one of these during the 2002 Daytona 500 NASCAR race, climbing out of his car during a red flag stoppage to look at his right front fender. Unfortunately, according to NASCAR rules, this is illegal, and he was sent to the back of the lead lap when the green flag came back out. The worst part is that he was leading the race when that happened!
 * Sergey Lukyanenko's Competitors novel mentions this absurdity several times in relation to starships. Humans on the Platform build these ships using matter synthesizers (i.e. replicators) based on plans in the station's database and available raw resources. While there are plenty of small fighter-type ships, even the giant ships have only one standard control console. Also, the entire thing has controls similar to a car, including pedals for acceleration and braking, in order to allow any human to use them. This is justified in that the station and the plans were created by aliens to be reminiscent of a web-based space exploration game (the game actually exists in Real Life). Later on, though, a group of rebels modify a large ship to function as a command ship of sorts with multiple consoles jury-rigged so that the ship would have an actual crew.