OSIRIS CLASS BATTLECRUISER
Of Piconese origin, the six Battlecruisers of the OSIRIS CLASS was a pre-unification design that had just finished construction prior to the outbreak of the Cylon War. As such the original design did not incorporate much in the way of the ability to carry fighter sized craft - having only a small hangar amid-ships. Instead it was a design that depended more on it's impressive battery of Turbo-Laser Cannons for ship to ship combat.
It did however provide the newly formed Colonial Fleet with a warship that could (for the early war period anyway) take on the heaviest Cylon Warships unless a Basestar with it's massed waves of fighters became involved. It also provided a valuable testbed for many of the technologies that were to be incorporated into the then building great Battlestars.
The OSIRIS CLASS Battlecruisers were generally used as the core element of the Fleet's Heavy Battle Groups.
As the war continued on, the need for anything that could carry fighters was greatly felt by the Colonials. Due to the Cylon's new tactics it was determined that it was critical to upgrade the design or the whole class would guickly be lost due to combat attrition before they could ever engage the enemy. As soon as room was available in the shipyards, units of the class were pulled off the battleline and fitted with a single Battlestar sized flight pod on the center-line. As the rebuilt ships (now known as the OSIRIS CLASS - MOD.II) reentered service, the original versions were relegated to escorting Battlestars, while the upgraded MOD.II versions took their places as the core of the Battle Groups. Later, as the more powerful TIGER CLASS Destroyers took over the head of the Battle Groups, the OSIRIS CLASS ships continued on with the valuable multipurpose ability of providing fighter cover for the group but still able to bring their formidable guns and missiles to bear on the enemy if needed.
DESIGN NOTE: The Battlecruiser
OSIRIS (pre-rebuild to MOD.II design) was one of the first ships in the Colonial Fleet to carry the new ASP Mk.I Point-Defense Fighter - the ship being specially modified to operate the type even before the fighter had "Officially" entered service.
(Background story based in part on one by Terry Ollila)
OSIRIS CLASS - MOD.II BATTLECRUISER:
LENGTH: 1,395 meters
STANDARD CREW: 1,900 Officers and Crew
PASSENGERS: 500 Marines
ARMAMENT:
4x Medium Turbo-Laser Cannons (2x Upper Forward, 2x Lower Bow)
4x Assault Cannons (2x Twin turrets, one turret on each side of the ship)
1x Solonite Missile Turret (4x Tubes - 72 missiles) (500 megaton Thunderbolt anti-ship/anti-surface missiles)
12x Twin, Heavy Dual-Purpose Blaster Batteries
40x Twin, Light Point-Defense Blaster Batteries
AIRWING:
2x Squadrons Viper sized fighters (24 each)
1x Squadron Adder Mk.II Strike Fighters (24 aircraft)
2x Condor Class Drop-Ships
1x Transport Squadron - 6x Alpha Class Shuttles - 6x Micro-Shuttles