An Imperial Colossus Siege Tank

The Colossus, also known as the Colossus Bombard or Colossus Siege Tank, is an open-topped self-propelled artillery piece commonly used by the regiments of the Imperial Guard, and it is one of the oldest and most renowned siege weapons still in use during the 41st Millennium. The vehicle is usually deployed by the Guard during sieges of fortified enemy emplacements and against structures being used as cover by the enemy during urban combat. The Colossus is armed with one of the largest and most powerful mortars used by the Imperial armed forces, known as the Colossus Siege Mortar. The Colossus is based on the common Chimera armoured personnel carrier chassis, and like the Imperial Bombard mobile artillery piece has a crane installed on its rear to lift its heavy siege shells and move them into place to be loaded into the siege mortar. The Colossus and the Bombard are nearly identical in appearance, leading to many cases of mistaken identity between the two artillery pieces on the battlefield.


The Colossus is armed and also named after the weapon it carries, the Colossus Siege Mortar. This weapon is the largest and most powerful mortar used by the Imperial Guard. The weapon fires special high concussion shells, which upon impact create explosive shock-waves that are capable of crushing bones, cracking rocks, and pulping flesh. The weapon is mostly used to destroy enemy infantry in cover, since the shock-waves produced by the Colossus' shells are able to kill their soft targets without first destroying their hard cover, but the Colossus is also capable of destroying even fortified targets, crushing the defenders beneath tons of rubble and debris. The Colossus' range is equal to that of the much more common Basilisk artillery piece, and like most mortar weapons it is incapable of firing directly at its targets. The Colossus is also equipped with a hull-mounted Heavy Bolter, which can be replaced with a Heavy Flamer. The tank can also be outfitted with camouflage netting, an enclosed crew compartment, a Hunter-Killer Missile Launcher, a Dozer Blade, extra armour plating, and a Pintle-mounted Heavy Stubber or Storm Bolter.

Known Formations

  • Emperor's Wrath Artillery Company - An Emperor's Wrath Artillery Company will begin the Imperial Guard's march to war, preceding the troops and vehicles with a thunderous barrage of heavy artillery fire. The battlefield is turned into a smoking, crater-strewn ruin, amidst which the enemy can find no cover or shelter from the death raining down upon them. These bombardments can last for solar hours, days, weeks, or even longer, and few defences can withstand the sheer destruction that is unleashed. These companies usually consist of three ordnance batteries, with each battery ccomposed of up to three Basilisk or Colossus artillery tanks and a single command Chimera tank.

Known Users of the Colossus

  • Imperial Guard - Many regiments of the Imperial Guard field the Colossus during demanding sieges and urban battles.
  • Iron Warriors Traitor Legion - The warbands of the Iron Warriors Chaos Space Marines make use of many types of artillery and mortars during their sieges, including the Colossus, many of which have been captured from the Iron Warriors' Loyalist opponents.

Adeptus Mechanicus Technical Specifications

Technical Specifications for this vehicle are not available in existing Imperial records.

Also See


  • Codex: Imperial Guard (5th Edition), pp. 53, 103
  • Imperial Armour Volume Seven - The Siege of Vraks - Part Three, pg. 134
  • Imperial Armour Volume Twelve - The Fall of Orpheus, pg. 204
  • Warhammer 40,000: Apocalypse (6th Edition) (Digital Edition), pg. 144
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