The Imperial Overlord-class Battlecruiser was based by the Adeptus Mechanicus on the design of the Acheron-class Heavy Cruiser in an effort to create a Cruiser-sized warship with the long-range punch and potent firepower of a true Battleship.
The design of the Overlord-class is generally considered a success in regards to it being a Battlecruiser possessing the long-range capabilities and firepower of a Battleship, despite many problems with its design. Difficulties in replicating the Acheron-class' power transmission systems led to the Overlord-class possessing only an armoured prow and standard Cruiser torpedo tubes in place of the Acheron's more powerful forward weapons batteries. Fortunately, this modification also freed up enough power to allow the installation of an upgraded dorsal Lance turret and row-upon-row of broadside weapons batteries, providing a range comparable to the vessel's other long-range laser batteries. These changes resulted in the long-ranged firepower that the Overlord's designers had hoped for when they had outlined the tactical requirements for the new Battlecruiser. Further difficulties in actually building the Overlord-class, however, meant that each one had to be painstakingly constructed at the Cypra Mundi orbital shipyards that serve as the headquarters of the Imperial Navy in the Segmentum Obscurus, and as such very few entered service with the Battlefleet Obscurus, with only three seeing action during the Gothic War.
A successful early illustration of how workable the Battlecruiser concept can be, the Overlord is as fine an example of a pure warship as can be found. Most Rogue Traders find the ship is poorly suited to anything other than combat, as its enormous weapons systems place a colossal strain upon the plasma drive. Some Rogue Traders strip out the extensive macrobatteries, freeing up space for other Components, but others regard this as a foolish and blinkered waste of some of the most elegantly designed and lethally effective weapons systems in the galaxy. Manufactured in the vast orbital shipyards of Cypra Mundi (as well as at other shipyards in lesser numbers), the Overlord is a difficult vessel to construct, but faithful and fierce in its service to Mankind. It does not waste space on massive Attack Craft hangars or the temperamental Nova Cannon. Instead, most designs use powerful long-range Macrocannon batteries and Lance turrets, backed by prow torpedo tubes. This simple, proven, and effective weaponry plays to the strengths of Imperial Navy tactics and Imperial technology. The design is an ancient but successful one, and new examples of the class are still commissioned every decade or so.
Notable Overlord-class Battlecruisers
- Cypra Probatii - The Cypra Probatii was completed partway through the Gothic War and arrived in the Gothic Sector only after a long and dangerous Warp journey from Cypra Mundi. It later had its point-defense turret array upgraded.
- Righteous Power - The Righteous Power fought in the Taros Campaign. It scored the killing blow on the Or'es El'leath (Custodian)-class Battleship A'Rho.
- Flame of Purity - Fought in the Gothic War alongside the Sword of Retribution, protecting strategic star systems from the Chaos raiders that plagued the Gothic Sector.
- Sword of Retribution - Fought in the Gothic War alongside the Flame of Purity protecting important star systems from Chaos raiders.
- Hull: - 5.3 kilometres, 0.85 kilometres abeam at fins approximately.
- Class: Overlord-class Battlecruiser
- Mass: Approximately 31 megatonnes.
- Crew: Approximately 100,000 crew.
- Acceleration: 2.4 gravities maximum sustainable acceleration.
- Battlefleet Gothic Rulebook (Blue Book), pg. 109
- Imperial Armour Volume Three - The Taros Campaign
- Star of Damocles (Novel) by Andy Hoare, pg. 218
- Rogue Trader: Battlefleet Koronus (RPG), pg. 22