Head Canon: The Klingon ships of Discovery season 1

Head Canon: The Klingon ships of Discovery season 1

The very un-Klingon looking Klingon ships seen in Star Trek Discovery's Klingon-Federation war.

These ships look so radically different from other Klingon designs for a good reason: these are NOT in fact Klingon ships.  These are actually old Hur'q ships, captured by the Klingons during the Hur'q invasion in Earth's 14th century A.D.  These ships were captured and used by the Klingons until eventually being surpassed technologically by Klingon designs.  The ships were then either abandoned or kept as heirlooms by the great houses, passed down through the generations.  Even in the 23rd century, some of these ships would be used as flagships by the leaders of the great houses.  The ships would no doubt be upgraded and augmented with Klingon technology over the centuries.  As the Federation-Klingon War of 2256-2257 was at least initially fought by the fleets of T'Kuvma and the great houses (on the Klingon side), this would explain why the majority of Klingon ships seen in early engagements (such as the Battle of the Binary Stars) are these older originally Hur'q ships.  Needless to say, some number of these ships would be severely damaged or destroyed during the war.  Following the end of the Federation-Klingon war, the ascension of L'Rell to power as chancellor and the unification of the Klingon Empire's forces under the Klingon Defense Force, and the launch of the new D7 class battlecruisers, these older ships (those that were not destroyed during the war) would be retired and mostly scrapped for parts and raw materials.  As many of these raw materials would be needed to build the new fleet of D7 and later K'tinga class battlecruisers, these centuries old, klingonized Hur'q ships would no longer exist by the end of the 23rd century.