The USS Eldridge was a ship used in Earth's second world war to escort goods to North Africa and Europe.
History
The Eldridge was part of 'The Philadelphia Experiment', which was supposed to make the ship invisible. However, the project bent the laws of time and space and caused the ship to travel through time. The crew who didn't die were driven insane. The Time Lords tried to stop the project, but were thwarted when the ship fell through a dimensional rift and ended up on the sea floor. (BFA: The Macros)
For some reason, the ship let loose a blast of Vortron Energy and brought Vashta Nerada and an alien shark into the 23rd century with radiation poisoning. The gateway caused by the ship was closed by the Eleventh Doctor and Amy Pond. (VG: Shadows of the Vashta Nerada)
