The Helstorm Rocket Battery is an experimental artillery piece used by the Empire of Man as a means to shower the enemy with a hail of explosive rocket munitions. The Helstorm Rocket Battery was first inspired by a particularly impressive display of fireworks in the city of Altdorf. Early prototypes infamously blew apart an entire floor of the Imperial School of Engineers, but the soot-blackened Engineers persevered and succeeded in creating a deadly, if unpredictable, weapon. The shrieking rockets fired by this bizarre machine can be wildly inaccurate and frequently target nothing more than the ground. However, when these rockets do land on its intended target, the results are devastating; entire regiments can be blown apart by a series of earth-shattering explosive impacts. After Count Boris Todbringer was almost hit by an errant barrage, they were dubbed "Helstorm" rockets after the colorful language he used to reprimand the unfortunate crewmen.
- Warhammer Armies: The Empire (8th Edition) -- p. 49