Black hole converter
From Tardis Wiki, the free Doctor Who reference
Black Hole Carriers were used by the Time Lords in the Last Great Time War.
The Master made use of a black hole converter on board his warships in the Time Lord Empire feeling that if he was denied control of the Earth then he would rather destroy it. (DW: Last of the Time Lords)
Like name says. Each of these ships carries a black hole which can be used as a weapon since they were created
