sentences:  These drifts closed in 1934 and was replaced by the Waunffynhonnau drift (new drift or Wimpey drift), which employed over 300 men in 1945.The mine was closed by the National Coal Board in April 1954, with most of the workforce going to Carway or Pentremawr Colliery.The site was later opened up as part of Celtic Energy's move into opencast mining, called "Ffos Las", but was closed in 1997.