The Steamrunner-class is an unusual design for a Starfleet vessel, the nacelles are partially built into the single-hulled structure. The navigational deflector array is connected at the end of the warp nacelles. The main shuttlebay is located directly in front of the ship.

The Steamrunner was a CGI only model created for Star Trek: First Contact by Alex Jager at ILM. Although it's design appears modern, it's registry would suggest the 2350s.

USS Appalacia NCC-52136
   Part of the armada to defend Earth against the Borg incursion of 2372.
   "Star Trek: First Contact"

Length: 355m
Speed: 9.8
Armament: Seven Type 10 phasers
Two torpedo launchers