Federation tug (2374)
A Federation tug was a class of small specialized tug starships used exclusively for towing damaged or disabled vessels. These ships were used by the Federation and operated by Starfleet in the 24th century. 

During the Dominion War, tugs were utilized in the evacuation of disabled vessels from battle zones. The  was one such starship to benefit from these utility vessels in 2374. ()

Appendices

Background information 
This class was never specifically identified on screen, nor directly in the script. It was referred to, offhand, in a script note reference which indicated that "a couple of the ships are being towed, unable to proceed under their own power."

According to a comparison chart drawn up by Gary Hutzel and Larry Nemecek, the length of the Federation tug, which they had listed under the name "tug boat", was 216.5 feet in length. . Its appearance in  makes it stand out as one of the few utility vessels, apart from the shuttles and cargo management units, of Starfleet ever to be shown on screen.

According to Issue #140 of the Star Trek: The Official Starships Collection, the Federation tug was approximately 90 meters, or 295 feet, in length, had a maximum speed of warp factor 6, and a crew complement of 6. The crew was composed largely of engineering specialists.

Studio model 
The episode "A Time to Stand" needed a shot of a retreating flotilla of Starfleet vessels. To beef out the scene, the production staff built several new ships, kitbashing them out of parts from commercially available AMT/Ertl Star Trek model kits. Members of the production team who pitched in to build the models for the episode were, among others, Gary Hutzel, Judy Elkins, Adam Buckner, and Anthony Fredrickson. 

Elkins was directly responsible for the construction of the tug, which was affectionately called the "USS Ertl" among the staff themselves; however, the model itself was not given any formal markings to indicate a name or registry.   The warp engines were those of a  Romulan warbird, originating from AMT kit number 6858. 

Tug (2374)

ja:連邦曳航船