Elongation

The increase in length of a material stressed in tension.

Embankment (or Fill)

A bank of earth, rock or other material constructed above the natural ground surface.

Embrittlement

Loss of ductility of a material resulting from a chemical or physical change.

Emergency Controls

Those controls that stop power to machine or components.

Emergency Recovery Shaft

See Rescue ShaftAn unplanned additional shaft required to remove obstacles/obstructions and/or retrieve or repair the MTBM. The rescue shaft may need to function as a jacking shaft to complete the drive..