Shock cannon

The shock cannon is the secondary long range artillery cannon developed for the terran siege tank. They come in 120mm and 180mm variants. These cannons fire shells of superheated tungsten, and can deal heavy damage to clumped fortifications, but the siege tank must be locked into a stationary "siege mode" in order to fire it.

The 120mm variant, or the Arclite shock cannon, was developed by the Terran Confederacy for the Arclite siege tank, and was designed to fit the Confederacy's combat doctrine of a mobile force. As such, while the cannons would need to be stationary to fire, the siege tank could enter a tank mode to move around the battlefield. While these were most phased out by the Second Great War, mercenary companies such as the Siege Breakers and elite units such as Shock Division continued to use the 120mm cannon.

The 180mm variant was developed for the Crucio siege tank, and was an improved version of the Arclite's shock cannon. However, marines distrusted the accuracy of these shells, as they had the tendency to cause friendly fire. Specialized shaped charges and Maelstrom rounds were developed for the 180mm shock cannon.