BortaS bIr class

The bortaS bIr-class was a Klingon starship class, a battleship in service to various Great Houses of the Klingon Empire in the 2250s decade. 

Specifications
The class name meant cold revenge in Klingonese. ( partwork)

This was one of four Klingon attack ship classes, all variants of the same basic spaceframe. Besides the bortaS bIr, the other Klingon attack ship classes were, and. The ship consisted of a spear-like elongated primary hull, framed by a pair of long, bulky and forward-facing warp nacelles with weapon ports. The nacelles and neck section were connected by a compact engineering hull marked with a circle and impulse engines at its stern. ( The bortaS bIr was a battleship, armed with disruptor beam arrays and photon torpedo launchers.

In 2256, ships of the class belonging to Great Houses loyal to Kol, son of Kol-Sha received a House of T'Kuvma cloaking device. 

Service history
Ships of the class were employed by the Klingon Great Houses by 2256. 

Ships of this class were also used by Klingons of the mirror universe around the same time. 

Several vessels of this class fought in the war between the Federation and Klingon Empire, also known as Burnham's War, starting with the Battle of the Binary Stars in May 2256. 

In November 2256, General Kol, son of Kol-Sha, traveled aboard a BortaS bir-class ship to claim the crippled at the binary system. 

In 2257, a pair of bortaS bIr-class battleships were part of an armada gathering in the Sol system to attack Earth. The armada disengaged and returned to Klingon space when Chancellor L'Rell ended the war. 

In 2410, the temporal displacement of J'Ula and many of her forces of House of Mo'Kai from the Defense of Starbase 1 to present-day, the bortaS bIr class returned service. 

Ships of the class, including from a 2256-era mirror universe, were involved with transtemporal events instigated by $𝜇$ at Pahvo.