HERDMANS FLAX- SPINNING MILL SION MILLS CO.TYRONE NORTHERN IRELAND Opened 1835, closed 2004, Four brothers from Belfast, James, John and George Herdman, built the mill in 1835 to complement the flax spinning business in Sion Mills. At its height, 1,500 flax mill workers were employed and the work continued for 170 years, ending in 2004 with the mill’s closure. In October 2010 a derelict part of the Sion Mills was gutted by Fire . The mill, ceased spinning linen in 2004. The company that owned the mill went into receivership in 2011. The Herdman's Mill site in Sion Mills has now been bought by a County Tyrone lottery winner.