Complex sentence: In 1908 the colliery had 5 mine shafts and employed 400 underground and 150 above ground workers who were managed by Peter Gorton, and his undermanagers T Pownall, John Grundy and P Bullough.
Split into simpler sentences: In 1908 the colliery had five shafts and employed 400 workers underground and 150 above ground. The colliery was managed by Peter Gorton, and his undermanagers T Pownall, John Grundy and P Bullough.