Haakona class

The advanced warbird was a class of battleship used by the Romulan Republic and the Remans in the early 25th century. It was a refit variant of the warbird. 

History
The Haakona-class was originally designed by the Romulan Star Empire for the use of the Romulan Star Navy but was never adopted by the service. It was named for then-Subommander Taris' warbird.

The class was partially inspired by data gathered during an abortive attempt to steal the Starfleet prototype USS Prometheus (NX-59650) around Stardate 51462 in 2374. This data was merged with Romulan technology to produce a warbird capable of splitting into two independently warp-capable sections.

At some point the design fell into the hands of the Remans and the Romulan Republic and by 2409 it was in use by both. 

Technical data
The Haakona-class featured a cloaking device. Structurally it was effectively the result of bolting a guardian warbird on top of a  assault warbird. These sections could perform a dual vector separation maneuver during combat, breaking the vessel into two independently warp-capable sections and allowing the Ha'nom-like section to provide increased support to the Ha'feh-like section.