 The battalion's DieHard Tunnel Rat section cleared the extensive Vietcong tunnel systems with little more than small arms and demolitions.The battalion received four Meritorious Unit Commendations for actions during the Vietnam War.Some time following its return to Ft. Riley, the battalion was reorganized as a mechanized engineer battalion, composed of one headquarters company ("HHC"), four line companies (A-D) and an (E Company).