Freighter convoy to Pentath III
These two Cardassian freighters were deployed in response to an outbreak of Rudellian plague on Pentath III, in 2372. The Cardassians prepared seven convoys to transport medical supplies and relief workers over a period of a week. Among the ships in these convoys were vessels of this design. Because the Cardassians didn't have the warships available to protect the relief convoy, they asked for Starfleet protection. The USS Defiant was assigned to escort convoy number six. On stardate 49648, the Defiant was engaged by a group of Klingon raiders that were attacking the freighters, an engagement which eventually set the stage for the apparent, and inadvertent destruction of a Klingon civilian transport ship. (DS9: "Rules of Engagement")
Transport evacuating Quatal Prime
In 2373, a Maquis raider commanded by Michael Eddington fired on a Cardassian transport of this design, that was evacuating Cardassians from Quatal Prime. The Maquis disabled the transport, causing it to lose power and slowly spiral down toward the atmosphere of the planet.
The transport was rescued by the USS Defiant, which towed it free of the gravitational pull of the planet. After some rudimentary repairs were made by a repair team from the Defiant, the transport was able to limp back to Cardassia. (DS9: "For the Uniform")