The Fenlon-class was a Federation class V monitor starship in Starfleet service in the 23rd century, with an initial mark II configuration becoming active on reference stardate 1/9701. An upgraded mark IV configuration entered service on stardate 2/1010.
The Fenlon vessels crewed 72 crewmembers in the mark II design, increased to 76 crew in the mark IV configuration, both arrangements with space to carry 20 SFMC troops and 20 passengers. Additionally, the Fenlon could carry 5,000 metric tons of cargo, rated at 100 SCU (standard cargo units). Unloaded, the mark II Fenlon vessels weighed 48,080 metric tons, while the mark IVs weighed 48,335. The spherical Fenlon-class and measured 120 meters in length, width and height.
The Fenlon computers were of the M-1 type, and the vessels were loaded with three standard (6-person) personnel transporters, one 20-person transporter, a 22-person emergency stage and a single cargo transport stage. There were also six Federation shuttlecraft standard to these vessels' shuttlebays. These vessels were designed for deep-space stationing near sensitive worlds and other planetary outposts with their own support vessels. The Fenlon vessels were mainly put in place to organize with and support fleets of smaller cutters and fightercraft found on such outposts.
The Fenlon antimatter reactors were FSLB type, rated to cruise at nine-tenths the speed of light with impulse engines of the FIC-2 type on the mark II and FIB-3 type on the mark IV. The Fenlon vessels had ten phaser emitters, of the FH-2 type on the mark II and FH-4 type on the mark IV in three multiple-mount phaser banks, with arcs of fire to fore (2 emitters) as well as port and starboard (4 emitters each way). The vessels had no launcher weapon emplacements and were defended by FSD (mk II) or FSF (mk IV) model deflector shields.
By the later half of the 23rd century, the Fenlon was in full service production with over 876 units having been constructed. By the mid-2280s, 334 mark II vessels and 130 mark IV vessels were currently in service, with 110 mark II vessels and 42 mark IV vessels having been consigned to reserve fleets. One vessel of each type was taken from service and detailed to Starfleet Training Command, with other vessels out of service due to 132 mark II vessels and 68 mark IV vessels having been destroyed and 4 mark II vessels and 2 mark IV vessels listed as missing. 39 mark II vessels and 8 mark IV vessels had been scrapped by that point, and 4 mark II vessels and 1 mark IV vessel have been sold to private commercial concerns. In the 2280s, the Fenlons were produced at Alpha Centauri's shipyards at a rate of about 2 per year. (FASA RPG module: Federation Ship Recognition Manual)
Presumably, the first ship of this series would have been called USS Fenlon, although such a vessel was never specifically named in the sources mentioning this class.