A Silver color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a shield blazoned: Per fess, enhanced Argent and Gules, in chief two bars of the second, in base a pickaxe palewise with handle couped surmounted near foot by a bayonet fesswise all of the first. Attached below and to the sides of the shield a Silver scroll inscribed FAISONS in Red letters.
Red and white are the colors of the Corps of Engineers. The two red bars on the white (silver) part of the shield, taken from the coat of arms of George Washington, symbolize Washington, D.C., the home area of the organization. The pickaxe and bayonet allude to the Battalions combined engineer and combat mission. The motto translates to Lets Do.
The distinctive unit insignia was originally approved for the 140th Engineer Battalion (Combat) on 30 June 1955. It was redesignated for the 140th Engineer Battalion on 4 January 1968. The insignia was rescinded on 26 December 1974.