Pytheus Class Heavy Cruiser (as of 2030 Rebuild):

The USS Pytheus NCC-1013 was initially built, in 2221, as part of Starfleet's projected requirement for a single heavy cruiser of Warp 6 capable heavy cruiser to back up the fleet guarding the troublesome Kzinti border.

Rebuilt in 2230 and upgaded into a Warp 7 capable starship.

NCC-1013 USS Pytheus basic Service History:

2221 Launched & Commissoned.
2220's Involved in many border skirmishes with Kzinti warships.
2230 Warp 7 engine & Warp nacelles upgrade.
2230's Played a major part in third Federation - Kzinti War.
2245 Received Duotronic computer core upgrade.
2246 Reassigned to Klingon front durimg the 4 Years War.
2249 Returned to Kzinti border fleet.
2252 Received extensive battle damage, following a massive Kzinti drone missile salvo, too severe to be cost effective for repair.
2252 Scrapped.