The buildup of post-Dreadnought battleships by Erusea and its allies in the early 1930s posed a great threat to the Coalition of Usean States, and their ally Osea also found themselves behind in terms of capital ship design. Forster Shipbuilding met an Osean Navy RFP with the Bannion class's design, and won a contract to supply the Osean Navy with four vessels. When the Great Usean War broke out, however, the first two ships were delivered to the CUS upon completion, where they fought against Erusean Belkan-designed battleships and Ugellan capital ships with enormous success. The Osean Navy received its first four vessels at the advent of the Eastern War. Although occasionally overwhelmed by numerically superior Verusan escort craft, they decimated capital ships imported from Ugellas with their speed and maneuverability, and by the end of the war ten more ships had been ordered. Only three were delivered, however, and six remained near-completion in Forster's drydock facilities when the war ended, and the half-completed BB-75 was broken up. Mothballed in case the Cold War ever went hot for two decades, the OMDF deemed them a burden and they were offered to the highest bidder for the next several years at increasingly lowered prices. Osea was unable to find customers until finally in 1980 Erusea's Second Republic sought to rearm its navy after most of its Eastern-supplied vessels were lost in the Good Friday War. The last six vessels were delivered to Erusea at a relatively low cost of $500 million OSZ each (adjusted for 2010 value) and indigenously modernized over the next decade.
Ships
UCS Unity (BB-04) - Delivered in 1934, she successfully sank the Ugellan battleships Mizuho and Takezō before conducting operations resulting in the loss of the EruseanSyn class battleships Hel and Hermóðr. Though not modernized, with funds instead going to carrier acquisitions in the next few decades, she was retained by the FCU Navy in a ceremonial role until converted into a museum ship in 1984. She was destroyed in the 2005 Saint Ark meteor impact.
UCS Resolution (BB-05) - Delivered in 1935 and sunk by the Ugellan flagship HIUMS Takezō in 1937.
OFS Bannion (BB-62) - Delivered in 1936, she single-handedly sank the Verusan Mizuho class battleships Feng and Huang in one engagement. Nicknamed "the Extinguisher," she was kept in service and modernized throughout the Cold War until being retired in 2006 after 70 years of service. She became a museum ship in Shannon.
OFS Stockdale (BB-63) - Delivered in 1936 and stationed in the North Ceres. Conducted operations with the Rowan, Fairweather, and Yuktobanian Navy to destroy what remained of Emmeria's Regia Marina, including the flagship Gracemeria and her support ships Impero and Corona. Remained in service until mothballed in 1975 and eventually scrapped.
OFS Shelton (BB-64) - The first Bannion assigned to the Atlantic Fleet during the Eastern War, mothballed in 1967. Supplied to the Navarro regime in Leasath in 2015 along with two Kingfisher class CVs and operated as the ARL Lesáta (B1). Sunk by Aurelian forces in 2020.
OFS Harwood (BB-65) - Assigned to the Atlantic Fleet along with the Shelton in 1942 and mothballed in 1967. Modernized while in storage and reactivated during the Belkan War. After retirement in 2001, turned over to the OFS Goldfinch museum as an exhibit.
OFS Waldron (BB-66) - Assigned to the Pacific Fleet and supported landing operations in Verusa; kept in service after the war until mothballed in 1974 and scrapped in the 2000s.
OFS Rowan (BB-67) - Sunk by gunfire from the Corona in the Battle of Glednia.
OFS Fairweather (BB-68) - Sank the Corona and Impero at the Battle of Glednia, kept in service until mothballed in 1977 and scrapped in the 2000s.
OFS Tanager (BB-69) - Completed after the Great Eastern War ended in 1944. Sat in drydock in Shannon until sold to Erusea's Second Republic in 1982 and rechristened the FES Thor (BB-4) as flagship of the Aegir Fleet. Sunk in the Second Battle of Comberth in 2004.
OFS Thrush (BB-70) - Completed after when the Great Eastern War ended in 1944. Sat in drydock in Shannon until sold to Erusea's Second Republic in 1982 and rechristened the FES Loki (BB-5) as flagship of the Vanir Fleet. Damaged at the Battle of Farbanti, but repaired and returned to service before being sunk in the 2007 coup d'etat.
OFS Nightingale (BB-71) - Completed after the Great Eastern War ended in 1944. Sat in drydock in Shannon until sold to Erusea's Second Republic in 1983 and rechristened the FES Odin (BB-6) as flagship of the Aesir Fleet.
OFS Fantail (BB-72) - Completed after the Great Eastern War ended in 1944. Sat in drydock in Shannon until sold to Erusea's Second Republic in 1983 and rechristened the FES Vili (BB-7) as a component of the Aegir Fleet. Sunk in Waosun Harbor during the Second Battle of Comberth in 2004.
OFS Sicklebill (BB-73) - Completed after the Great Eastern War ended in 1944. Sat in drydock in Shannon until sold to Erusea's Second Republic in 1983 and rechristened the FES Mímir (BB-8) as a component of the Vanir Fleet. Sunk at the Second Battle of Tyler Island in 2005.
OFS Kinglet (BB-74) - Completed after the Great Eastern War ended in 1944. Sat in drydock in Shannon until sold to Erusea's Second Republic in 1983 and rechristened the FES Forseti (BB-9) as a component of the Aesir Fleet. Transferred to the Vanir Fleet in 2008 to make up for the loss of the Loki.