The Soup Cannon fires using the rules for Fire Throwers. It has Strength 2, Ignores Armour Saves and Slow to Fire special rules. If the Soup Cannon rolls a misfire The Halftank loses D3 Wounds with no saves allowed.
Source: Warhammer Armies Project: Unofficial 9th Edition (v2.2)
The Soup Cannon fires using the rules for Fire Throwers. It has Strength 2, Ignores Armour Saves and Slow to Fire special rules. If the Soup Cannon rolls a misfire The Halftank loses D3 Wounds with no saves allowed.