Not long after the launch of the originial USS Enterprise, the Utopia Planitia yards started with theorising about a frame specifically meant for civilian use. They got the specifications of the Constitution class and used it as a template; afterall, not having to design everything from the ground up would keep the costs of the frame low. They minimalised the engineering section to contain the bare minimum for starship operation, and removed 80% of the normal structures inside the ship to make place for easily swappable modules. A single nacelle, reused where possible from older or scrapped spaceframes, was placed on top of the aft portion of the saucer. Starfleet was looking over their shoulder, curious if a one-nacelled ship could meet their criteria.
Initially, the great firms that were still alive in the 23rd century didn't see anything in the frame, opting other shipbuilders instead to make them personalised ships. These came at a hefty price, though, and orders for the Standard Civilian Frame (noted as SCF-xxxxx in the registry) only started to come in when a certain postal service saw the benefits of this design, placed an order and used the first of the SCF frames to get an ambassador his long-awaited Romulan Ale, for which they were awarded with a contract to make sure the core worlds of the Federation got their packages as fast as possible. During testruns the ship barely made it to Warp 7; UPS deemed that fast enough and after the request for the addition of four phaser banks was approved, the ship was pressed into service in 2260.
The Mark 1 SCF saw a good run before being replaced by the Mark 2 in 2290, which provided a higher top speed and a higher cargo capacity. Moving the engineering hull to the aft of the topside also meant that this design would be able to make planetfall and re-enter orbit if the situation required it.

Initially, the great firms that were still alive in the 23rd century didn't see anything in the frame, opting other shipbuilders instead to make them personalised ships. These came at a hefty price, though, and orders for the Standard Civilian Frame (noted as SCF-xxxxx in the registry) only started to come in when a certain postal service saw the benefits of this design, placed an order and used the first of the SCF frames to get an ambassador his long-awaited Romulan Ale, for which they were awarded with a contract to make sure the core worlds of the Federation got their packages as fast as possible. During testruns the ship barely made it to Warp 7; UPS deemed that fast enough and after the request for the addition of four phaser banks was approved, the ship was pressed into service in 2260.
The Mark 1 SCF saw a good run before being replaced by the Mark 2 in 2290, which provided a higher top speed and a higher cargo capacity. Moving the engineering hull to the aft of the topside also meant that this design would be able to make planetfall and re-enter orbit if the situation required it.
