(Extract from FAQ 2010)
A battle barge is not a class of vessel, but rather it is the name given to any vessel configured to fulfill the role of battle barge. Because of this, it is theoretically possible for any large capital ship to fulfill this role, although the battle barges specially designed for the Space Marines by the Adeptus Mechanicus are the most common example.
However, some older Chapters, particularly those dating back to the First Founding, maintain much more ancient and revered vessels dating back to a time when the Adeptus Astartes and the Imperial Navy were more closely united than they now are and commonly employed reconfigured Navy vessels as battle barges. Such vessels are completely unique; indeed, some of them were later used as the basis for new Imperial Navy ship classes, and as such are greatly venerated by the Space Marines. Some Chapters rely on truly unique vessels imparted upon them for a specific role or to meet some dire threat. Others simply retain vessels they received millennia ago or gained through other means. The Space Wolves, a traditionally minded Chapter, is more immersed in the customs of its homeworld of Fenris than most Chapters and has access to only the most rudimentary of shipyards, and they are perhaps the best known example of this, relying as they do on an Emperor-class battleship to fulfill the role of battle barge.
Choosing a Battle Barge
In addition to their fleet list, any Space Marine fleet may include a single Venerable battle barge (meaning only one!), which may be any Imperial or Chaos battleship, grand cruiser, battlecruiser or heavy cruiser (painted propriately of course!). This replaces one of the battle barges allowed in the fleet. The normal cost must be paid for the ship, plus an additional +35 points for the cost of the Space Marine crew. This vessel represents an ancient, revered icon or a vessel granted with special dispensation. It is worth 100% victory points if crippled or 150% victory points if destroyed. A Venerable battle barge benefits from all the Space Marine special rules, but since it is already heavily reconfigured to make it into a battle barge, it may not be given any of the optional refits or upgrades listed in its profile – it must be used exactly as is, in its basic form. For example, a Mars battlecruiser
taken as a Venerable battle barge may not be given a salvaged targeting matrix for +15 points and can only earn such a refit in the course of a campaign normally. The only exceptions to this are the special refits that the Space Marines themselves make to their battle barges, as follows.
Launch Bays and Thunderhawks
Any launch bays on a Venerable battle barge have their launch capacity halved (rounding up). For example, an Imperial Mars battlecruiser with two launch bays each side is reduced to one each side, and a Chaos Styx heavy cruiser with three launch bays on each side is reduced to two each side. The launch bays are configured to carry Thunderhawks following the rules detailed beforehand and on p.21 of Armada, and they cannot be used to launch any other form of attack craft. This is a compulsory refit that applies to all Venerable battle barges equipped
with launch bays. A Venerable battle barge not equipped with launch bays cannot take Thunderhawks.
Prow Weapons and Boarding Torpedoes
Any Venerable battle barge equipped with a prow weapon (regardless of what it is) may if desired replace it with strength-6 torpedo tubes (speed: 30cm) for no change in cost. As with all Space Marine vessels, these tubes may also be used to launch boarding torpedoes. These boarding torpedoes are manned by Space Marines and get a +1 to their hit and run attacks when they hit an enemy ship.
