The Chaos Hellfire-class Heavy Cruiser was an early attempt by the Adeptus Mechanicus to mount large batteries of various weapons onto a Cruiser hull. Initially the ships were only fitted with relatively weak, although numerous, Lance and weapons batteries, however after several years of careful observation and tinkering with the starship's power output enough, energy was able to be diverted to increase the range of the Lance batteries. The Hellfire-class ships became a formidable adversary and were used in planetary sieges and system blockades.
Although the ship's huge arsenal was of great use to fleet commanders, its inability to keep pace with other vessels of a similar design was a hindrance to fleet manoeuvres. Also they were considered to be an easy target for any enemy who were actually able to get close to them, due to their lack of Void Shields. Having power drained into the Lance batteries came to a large degree at the expense of the shield generators, which was fine if the ship was standing off and firing at a distant target or a planetary surface, but dangerous when the vessel was taking part in a large-scale fleet engagement at close quarters.
Another problem with the design was that all space in the vessel not taken up by engines and plasma generators was filled with the massive armouries required to hold ammunition for its myriad weapons systems. This meant that the vessel's crew quarters were very cramped and that the Hellfire-class was not able to carry a large supply of stores. In turn this meant the Hellfire was not much use for long-range patrols, unless supported by a flotilla of transports and Escorts.
Morale on-board the Hellfire-class tended to swing from one extreme to the other, being high at times of conflict when the crews pulled together and did not mind the harsh conditions, effectively manning the vessel's weapons so that the ship's massive batteries reduced all but the most determined enemy to pulp. On the other hand, during the long periods when the ships were at spacedock or appointed to stand sentinel over some obscure star system, morale slumped to an all-time low when there was no room to move within the ship's cramped corridors without bumping into one's fellows. In such conditions the murmurings of discontent started to spread and many of these vessels and their crews turned from the light of the Emperor of Mankind to the darkness of Chaos. Of those Hellfire-class Cruisers that remain in Renegade hands, little is known of their whereabouts, but occasionally they resurface into Imperial awareness, usually during Chaotic blockades of Imperial systems or trade routes for which the class was so well-suited.
- Battlefleet Gothic Annual (2002)