Durham Mining Museum Operation of a Longwall Coal Cutting Machine
The slot made by the cutting machine is known as the 'cut' or 'kerf'. Normally the cut is 5" or 6" high and penetrates the seam to a depth of 4' 6" or 6', although cuts are sometimes made as shallow as 2' and as deep as 7'. If the cut is made at floor level, the seam is said to be 'undercut'. If halfway up the seam it is called a 'middlecut ...