The Battle Fortress is the mobile airship headquarters of the Battle Bird Armada that was built by Dr. Fukurokov. Despite its incredible size, it is easily capable of flight as well as staying afloat in water.
In 3237 the Battle Fortress was disguised as a smaller island near Cocoa Island, with an under-tunnel built beneath the seabed to connect it to the island, and allow easy access to the cavern network below. Eventually, Miles "Tails" Prower, T-Pup, and Antoine & Bunnie Rabbot D'Coolette infiltrated the fortress through the under-tunnel and destroyed a storage bay while fighting Speedy in Fukurokov's Mole Mech. This caused enough damage to the Battle Fortress for Armada troopers to evacuate to the upper decks while the ship took off to avoid flooding, and then flew away from Cocoa Island, dropping debris and venting fuel. As the Battle Lord punished Dr. Fukurokov by ordering him to make all the repairs alone, the Battle Birds remained unaware that the Babylon Rogues' zeppelin was on an intercept course with them. (SU: #17, #18, #19, #20)
Some time after this, Dr. Fukurokov picked up a Babylonian energy signature, and the Fortress headed for it's source within the Gigan Mountains. Discovering that the Babylon Rouges had found the Key to Babylon Garden and were attemtping to flee with it, the Battle Lord had the Fortress plot an intercept course and the key was successfully recovered while the Rogues were forced back into the Armada. The Armada and Battle Fortress then made their way to Babylon Garden's hidden location beneath New Mobotropolis, and attacked the city while the Battle Lord fought off Ixis Naugus's attempt to take over the ship with his crystal magicks. Once in position over Castle Acorn, the Fortress fired its drill beam and the laser bored a massve hole to the Garden while the city was completely destroyed. After the Garden rose from beneath the surface and took to the skies, the Fortress fired anchor lines to tether itself to the other ship and was dragged along into the upper atmosphere. While still moored though, the Garden soon began to rapidly lose altitude for unknown reasons, and the Battle Lord ordered the all hands to abandon the Fortress as it was pulled down and crashed into some nearby mountains. (SU: #33, #34 #35, #36)
The Battle Fortress carried the entire compliment of the Battle Bird Armada, along with their various weapons and other equipment. It was capable of being submerged and being disguised as an island, and also possessed immense firepower. The fortress is armed with several cannons all over it, along with a giant drilling beam housed in its underside for attack and excavation purposes. Aside from having full training and housing facilities for the Battle Birds, the ship also features a flight deck and massive hangar for storing smaller vehicles, such as the zeppelin stolen by the Babylon Rogues. (SU: #18, #19, #33, #35)
- The Battle Fortress is based on the Battle Bird Armada's vehicle from the Tails Adventure videogame. In early story concepts for the Armada, it was referred to as the "Iron Kookabura," as revealed in the fifth volume of the Sonic Universe Graphic Novel Series.