Capitol Imperialis and it's armaments image - Warhammer 40K Fan Group

A Capitol Imperialis is a tracked Super Heavy tank (or in my opinion a titan tank) often used as a mobile command base for most Imperial Guard Regiments. Though heavily armored and protected by several Void Shields, it's sheer size and slow speeds limits the vehicle to defensive operations.

At almost fifty meters tall, the rhomboid-shaped Capitol Imperialis rivals a Titan in size. Solid adamantine plating and six Void Shield generators gives it a comparable level of protection. Its primary weapon is the massive Behemoth Cannon, so large that 4 Leman Russ Tanks could fit within it's barrel. The concussive force of firing the Behemoth Cannon can knock nearby troops off their feet and cause avalanches, while a single hit can kill thousands of enemy soldiers and vehicles, throwing them hundreds of meters into the air and producing a huge mushroom cloud. Secondary weapons include hundreds of Bolters for close-in defensive fire, and the hull can be electrically charged to repel boarders.

Within its massive hold a Capitol Imperialis can carry two full companies, whether Infantry or tanks. This allows the vehicle to act as a mobile bunker for troops, especially on inhospitable worlds, and the embarked soldiers can further support the Capitol Imperialis by fighting from its protective bulk. The command bridge situated deep within a Capitol Imperialis allows its regiment's commander the tools needed to command his troops efficiently. Vox-gear, pict-casters, logic-engines and a holo-map, all serviced by hooded Servitors gather, analyze and display information to allow the leadership to plan out their campaign.