Ancient City Ship

An Ancient city ship is a large city-sized spaceship within the science fiction television series Stargate Atlantis, long ago constructed by the Ancients. Dwarfing even a Wraith Hive-Ship and Ori battlecruiser, the city ship is the largest ship ever encountered in the Stargate universe.

Structure and technology

The ship is a snowflake-shaped platform dotted with skyscrapers, lower buildings in the six outlying sections, with the control tower in the center. However, most systems can be activated from an auxiliary control room. Due to its enormous size, the ship has been compared in size and interior space to Manhattan. Most of these ships carry a Stargate, usually located in the control room. Curiously, the city ship does not have a traditional outer hull. Instead, the atmosphere is contained within the vessel by a huge energy shield spanned around the city. Also, most of the structures are surprisingly fragile, requiring the aforementioned shield to protect them from naturally occurring phenomena such as hurricanes.

The city ship, as with most Ancient technology, is powered by Zero Point Modules, requiring three to achieve full functionality. However, most systems, like the energy shield, can be activated with only a single ZPM, and day-to-day power can even be supplied by Naqahdah generators. However, in emergencies where no ZPMs are available, some systems, like the shield, can be activated by harnessing energy from lightning.

The ship is also equipped with several systems encountered on most interstellar vessels, such as long range sensors , internal transporters, and sophisticated computer systems. The advanced internal sensors, that can also be used to track life forms, enable the City to sense threats, including chemical and biological ones. The City can automatically seal or open sections of the city to secure its population. It also carries a complement of smaller ships, Puddle Jumpers. These Jumpers are stored in two Jumper bays. One is located directly above the Control Room, from where the Jumpers can be either sent through the Stargate or exit the City via the retractable roof , and a secondary Jumper bay is located in the lower sections of the city. Atlantis also has five desalination plants to supply the city with fresh water, which it stores in large tanks in the superstructure.

The enormous vessel can descend into the atmosphere of a planet, and often resides on top of an outpost. But the ship can easily land on the ocean of any planet. Engines are lined on the bottom side of the city ship, with six sets of engines on each of the piers. This configuration was encountered on both Atlantis and the Asuran city-ship. However, when Atlantis left Earth for the Pegasus Galaxy, the city was equipped with two on each of the three large piers.

Interstellar travel, or even intergalactic, is achieved by the activation of the stardrive. The drive requires an enormous amount of power that can only be achieved by all three ZPMs working simultaneously. However, the Atlantis expedition managed to bypass the energy requirements of three ZPMs by using a geothermal power station and a single ZPM to get Atlantis into space and away from the planet. When in flight, the city is piloted from the Ancient Control Chair.

The activation of the stardrive is automatically preceded by the powering up of the inertial dampers, also requiring a significant amount of power.

Tactical systems

Atlantis' activated shield.

Defense of the vessel is provided by its all-encompassing shield, although it does require the presence of a ZPM to be activated. This shield can be expanded to cover a larger area than the city itself, although exactly how much area can be covered depends on the power available. When powered by three ZPMs, the shield can be extended to cover most of a planet the size of Lantea.

In addition, the city can be rendered invisible by linking the cloaking device of a Puddle Jumper to the shield generators. As a last resort, the enormous city can be submerged into an ocean, protected by its energy shield and attached to the ocean floor with an intricate clamping system.

As with Puddle Jumpers and Aurora class battleships, the city ship is equipped with Drone Weapons controlled by an Ancient Control Chair and launched from three ports on the ends of three arms of the city.

When not activated, the drones are stored in specifically-designed racks that can be replenished if reloads are available.

Encountered city ships

Several city ships have been encountered by the Tau'ri, all of them in the Pegasus Galaxy. However, outposts required for landing the city have been discovered on both Earth and Proclarush Taonas, indicating the possible existence of several city ships in the Milky Way's distant past.

Atlantis

Atlantis was the capital of the Ancient empire in the Pegasus galaxy. The City was once located on Earth in what is now Antarctica. Several million years ago many of the Ancients who inhabited Earth at that time relocated the giant city to the Pegasus Galaxy. After years of being under siege by Wraith ships in ORBit, the Atlantis inhabitants abandoned the city, traveling back to Earth via the Stargate.

The city was submerged in the ocean and was left like this to keep it intact and safe from the Wraith. Eventually, a team from Earth used the Stargate to travel to the City in search of knowledge and possible contact with its builders, ten thousand years after it was abandoned. Thanks to the presence of a Dr. Weir from an alternate timeline, the Atlantis Stargate had been programmed to only accept incoming wormholes from Earth's address at the time, meaning it was secure from any Wraith attempt to gate in. As such, the city lay dormant on the ocean floor for ten thousand years. However, when the Atlantis Expedition arrived, the ZPMs were nearly depleted, and the autonomous city released its clamps on the ocean floor and resurfaced.

Today, a team of humans from Earth makes up the bulk of Atlantis' urban inhabitants, and the city now acts as the secure main base for Stargate operations in the Pegasus Galaxy.

The Tower City Ship

Another city ship was encountered on a planet in the Pegasus galaxy, populated by a primitive people. This city was in much worse condition than Atlantis, having been attacked by the Wraith or exposed to the elements and largely buried since the Ancients abandoned it. The city's ZPMs were nearly depleted, and most of The Primary systems were inactive. Only the central tower remained visible. However, the weapon and power systems had remained active for a greater time, and were still used to defend the planet from the Wraith by humans with the ATA gene, indicating the crossbreeding of Ancients and humans on this planet. Also, this was the only encountered city ship that did not contain a Stargate.

The City Ship was controlled by a Lord Protector to protect the planet from the Wraith and intimidate the village nearby. When the Lord Protector was poisoned, his advisor, Otho, who was also responsible for the Lord Protector's death, succeeded him. He tried to destroy the nearby village for "defying their Lord Protector" using the City's drones, but Rodney McKay managed to stop him by powering the City's stardrive, depleting the already-weak ZPM. The City's drones and Puddle Jumpers were eventually brought back to Atlantis for later use.

Asuras

Another Ancient city ship, Asuras, was encountered in 2006 by the Atlantis Expedition. This city was constructed and inhabited by replicators emulating unascended Ancients, the result of a failed Ancient experiment to combat the Wraith. This city was in perfect condition, and fully powered. The ship was the centerpiece of a much larger metropolis which, like Atlantis, is located in an ocean.

Once the Asurans discovered Atlantis had survived the siege by the Wraith, they decided to attack Atlantis themselves for vengeance against the Ancients. Defending their home, the Atlantis Expedition overloaded the Asuras' ZPMs, destroying the city while in space. The Asurans would later rebuild their city ship. The rest of the Asuran cityscape remained intact on their homeworld.

Asuran Atlantis copy

In This Mortal Coil, a group of Asurans from Niam's faction created on another world, a duplicate of Atlantis filled with replicated Atlantis personnel as well as living flesh and blood copies of the Atlantis team including Dr. Weir constructed by nanites. The purpose of the experiment was in order to get closer to ascension. The team discovered the ruse, the Asurans intended to erase their memories and start over when Oberoth discovered their location and destroyed the city but not before the duplicated Atlantis team was allowed to escape.