Based on the Greer-class or Gagarin-class spaceframe, the Fisher class starships would have (instead of the secondary hull common to the Gagarins) a tow pad that could carry up to two standard transport containers. As needed, the ship's warpfield could be extended to include the additional container.
The standard crew complement was 50. Armament included 6 phasers. Maximum velocity was warp factor 8, though less with the containers in tow. (Jackill's Starfleet Reference Manual: Ships of the Fleet, vol. 1 [revised])
The prototype of the starship class was the USS Fisher.