Abstract: An underground vault formed of two housing sections, each section having an open end bordered by an outwardly projecting annular flange, the flanges being of like diameter to permit their mutual abutment when the two sections are placed together to form an enclosure, each flange having a plurality of circumferentially located, equally spaced hooks and slot configurations to lock the sections together when the sections are positioned so that alternating hooks and slots of one section are aligned with slots and hooks of the other section is disclosed.