B10 Battleship

before the end of the General War in 2285. Part of the reason was changes in the design as the war progressed. Originally designed with a small fighter compliment, the design evolved into a full carrier and finally to an SCS before it was completed. All of this created enormous cost overruns on an already strained Klingon economy
Klingon B10 Battleship: In 2269 the Klingons began constructing the largest ship ever built. It was estimated that completion would take 4 to 5 years. As it was, the vessel was never completed