Cunette

A cunette was a small ditch excavated in the main ditch of permanent fortifications, usually parallel to the scarp wall, that was designed to drain the bottom of the ditch and carry off rainwater. Cunettes were scaled to the area of the ditch they were intended to drain and could be as large as 4 feet wide at the top, 2 feet wide at the bottom, with a depth of about 3 feet. To promote good drainage and insure that run-off would flow toward the cunette the bottom of the main ditch was usually given a slight downward slope from the foot of the scarp and foot of the counterscarp to the cunette. Run-off carried by the cunette was either collected in wells or carried out the low side of a fortification through masonry lined blinded drains sunken under the counterscarp and glacis.

January, 2003