Temporal engine
From Tardis Wiki, the free Doctor Who reference
Temporal Engines are devices that allow multiple different timelines to exist simontainiously. Known engines were kept in the Red Waterfall facility for Chen-7 on Apalapuchia, which allowed 4000+ timlines to exist in seperate realities. Exhaust from the engines prevented Handbots from locating patients, such as the accidently admistered Amy Pond. (DW: The Girl Who Waited).