from Ship Recognition Manual - The Federation, 2nd Edition, FASA

Notes - circa 2287:

     The Fenlon is the only monitor Class in Star Fleet. Be-cause ships of the monitor type generally are used to patrol and maintain order over subjugated worlds, the UFP has little need for a vessel of this type, except near the borders. These ships patrol border systems and protect them from marauders and pirates. The spherical hull design is a drastic departure from normal Star Fleet designs. The engines are mounted centrally and are difficult to locate on a visual scan. The sub-light drive system is capable of moving the Fenlons at .9 warp for periods of up to 6 months. Of course, being stationed in-sys-tem or at a border outpost because their limited top speed limits their range, the monitors will seldom need this capability because they are always near their supply depots. The Fenlon Class monitor is seldom found alone. Its primary function is to support the cutters that are operating in the area. It will act as a heavy support vessel when the cutters have encountered a ship that they cannot deal with alone. The Fenlon, with its 10 phasers, is an unwelcome sight to smugglers, pirates, and marauders. Of the 876 Fenlons built, 334 Mk Ils and 130 Mk IVs remain in active service, with 110 Mk Ils and 42 Mk IVs in reserve fleets. One of each type is used by Star Fleet Training Command; 132 Mk Ils and 68 Mk IVs have been destroyed; 4 Mk Ils and 2 Mk IVs are listed as missing; 39 Mk Ils and 8 Mk IVs have been scrapped; and 4 Mk Ils and 1 Mk IV have been sold to private commercial concerns.
     The Fenlon is produced at the Alpha Centauri shipyards at a rate of 2 per year.