The Kass'l (Orca)-class Gunship (not to be confused with the orbit-to-surface Orca dropship used by the Tau in planetary operations) is an Escort level starship used in the Tau Empire's Kor'vattra. Unable to build an Ether Drive light enough to produce a normal escort at the time, the Earth Caste designed an ingenious system of mounting Gravitic Hooks on capital ships, such as the Gal'leath (Explorer)-class Starship, so that the Kass'l design could be transported within the capital ship's gravitic sheath. Once unleashed in battle, the Kass'l proved a powerful gunship able to contend with any Imperial or Ork vessel.
- Battlefleet Gothic Armada, pg. 105
- Battlefleet Gothic Magazine – Issue 19, pg. 23