Vorok's battle cruiser was a type of 22nd century Klingon battle cruiser that was in service during the early 2150s, under the command of Klingon Captain Vorok. The vessel was armed with forward and aft torpedo launchers, as well as an aft tractor beam.
In 2151, a Xyrillian ship hid in the plasma wake of this battle cruiser causing various on-board malfunctions to the ship. After being contacted by Enterprise NX-01, this battle cruiser fired upon the Xyrillian ship and locked it in a tractor beam. The Xyrillian ship was eventually released upon the installation of holotechnology aboard the Klingon ship. (ENT: "Unexpected")
In the script for "Unexpected", this Klingon vessel was described as "massive, battle-scarred, menacing." An ultimately unused but scripted line of dialogue had Vorok say that the craft and its crew had been away from Qo'noS for "a long time."
The bridge of Vorok's battle cruiser was represented with a set on Paramount Stage 8. (Information from call sheets)
This battle cruiser was a very much "unexpected" reuse of the K't'inga-class CGI model, used at the behest of the producers, despite the series being set over a hundred years before this Klingon ship class made its first appearance. A new CGI model was created to represent this ship, but the design was ultimately rejected.