The Kass'l (Orca)-class Gunship is an Escort starship used by the Tau Empire's Kor'vattra, the Tau Navy. The Kass'l is a much more nimble vessel compared to the Kor'vattra 's other primary Escort class warship, the Kir'qath.
Unable to build an Ether Drive compact enough to fit within the smaller spaceframe of an Escort at the time of the Kass'l-class' construction, 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 much larger 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 of similar class.
- Battlefleet Gothic Armada, pg. 105
- Battlefleet Gothic Magazine 19, pg. 23