0:37 In a more prosaic story, They were filming a TOS episode featuring the Romulans, BUT they discovered that they had mislaid the Romulan bird of prey model from "Balance of Terror" [my favourite Trek TOS Episode]. Between a rock and a tight shooting schedule, they grabbed the model of the Klingon D-7 instead, then wrote in a throw-away like for Leonard Nemoy quickly explaining Romulans were now using Klingon ship configurations. No one at Desilu expected ANYONE to give a sh*t 20, or 50 years on. The D-7 was a vicious looking ship, and I preferred it to the federation designs.

So the D7 was the Iowa class battleship of it's day.

My all time favorite to fly is the Command Cruiser D-7 . Upgraded energy weapons and a couple additional hard points, more reserve power.

So cool 😎

Actually, the Constitution-class sounded the death knell of Klingon military superiority. They just didn't realize it at the time. Then the Excelsior-class actually killed it.

I prefer my headcanon where the D7 and the K'tinga are actually the same class, with "D7" being a designation given by the Federation when first encountering it. Either the Federation didn't know what the Klingons were calling it, or they just didn't care because Klingon words like K'tinga are harder for humans to say than D7, and it's not like showing respect for Klingon naming convention was a priority for most people while actively at war with them. Sure there are on-screen differences in design, but we've seen ships given just as much of a visual overhaul when refitted before. Look no further than the Enterprise itself when it was given a major refit for The Motion Picture and following movies. It could *easily* have been called an entirely new class of ship, but no, same old Constitution class, different look. I think it makes the most sense to figure the same thing happened with the D7/K'tinga. Same ship, different names with different origins, and a major overhaul with updated tech and such at some point.

Late 2250s? Remember seeing this ship in the first season of Star Trek Enterpise which played 2151

It's just lore though. It doesn't matter