Definition of "canch"

An upcast fault is when the seam is thrown up; to counteract this a "canch" of top stone must be taken down outbye over from the fault, and a "canch" of bottom stone taken up inbye over from the fault, then level up to the bottom of your "canch" at the foreside of the hitch outbye over until you have a regular gradient to the seam on the hitch.

1879, William Bailes, Student's Guide to the Principles of Coal & Metal Mining, page 17

I would like to know, for example, the length of time taken to cut the 125 yards of face with the bar machine, the number of fillers employed on the same length of face, and what number of gatewaymen were employed to do the necessary canch work at the face.

1926, Institution of Mining Engineers (Great Britain), The Mining Engineer, page 281