Dimension Cannon

The Dimension Cannon was a device used in Pete's World invented by Torchwood. Rose Tyler used the device several times to try find the Doctor. Mickey and Jackie also used it to help save Sarah-Jane Smith.

The cannon was originally designed and constructed with the intention of allowing passage between universes, however it was unable to break through the barriers separating them. Because of this, the device didn't function at all until the events of the Dalek Invasion of Earth, when the walls of reality started to break down. In the aftermath of the war, it is stated that the walls would repair themselves, suggesting that the cannon will once again not function. (DW: The Stolen Earth / Journey's End)