A Siegebreaker Cannon is a type of Imperial ballistic weapon employed atop the carapace of the Dominus-class Knight Castellan. Siegebreaker Cannons are unsubtle gun turrets, fired by Servitor-brain sub-arrays slaved to the pilot's targeting systems.
They are capable of laying down a pounding bombardment of heavy ordnance to entirely carpet an area in flame and shrapnel and serve as effective area-denial wepaons for the super-heavy Knight Castellan.
- Codex: Imperial Knights (8th Edition), pg. 68
- Games Workshop Knight Castellan