Supergate

The Supergate is a massive Stargate developed by the Ori, spanning three to four hundred meters across. Comprised of 80 individual segments, the device draws its power from a black hole, the only force in the universe strong enough to sustain it indefinitely.

Overview
The Supergate was developed for the specific purpose of establishing permanent footholds in distant locations in the universe, permitting of enormous Ori ships or an entire armada of ships. The only known defense against the Supergate is to break the chain of connecting segments, causing a power surge that prevents the completion of the device. When it is completed, it is not known which way it can be destroyed.

While it is not known whether an active supergate can be destroyed - they can be disabled. It is possible to place a normal sized stargate alongside the supergate, and dial into it from a gate in another galaxy in close proximity to a black hole. By detonating a shaped thermonuclear charge toward the gate near the black hole, it is possible to make the wormhole jump from the normal stargate onto the supergate. The result is that the supergate is dialed into a black hole stargate. This will keep the supergate indefinately occupied - thus preventing incoming wormholes from the Ori galaxy. This plan was successfully executed, using a black hole in the Pegasus galaxy, resulting the destruction of both a Wraith hive ship and an Ori battlecruiser.


 * The concept from which this strategy is devised comes from the season two episode when the SGC dials a gate near a black hole and cannot disengage the wormhole.

The Stargate blocking the Supergate was destroyed to allow SG-1 to send the Sangraal to the Ori home galaxy. However, this allowed the Ori Army to resecure the device and send another six ships through to the Milky Way.