Abstract: A dual-track chassis includes an understructure (2) for carrying a load which is pivotal about a vertical axis (6) with respect to the understructure (2). The understructure (2) is supported on two crawler members (1) by joints (4), which provide two oppositely disposed points of support. The understructure (2) is also supported by a rocker member (9), the ends of which are in turn supported by the crawler members (1). In the normal position, the rocker member (9) is parallel to a line between the two points of support provided by the joints (4) and is rotatable about an axis lying in the vertical longitudinal center plane (8) of the chassis. The distance between an axis of rotation (5) and the vertical axis (6) is smaller than the distance between the rocker member (9) and the vertical axis (6). Stability is increased by supporting the understructure (2) on the rocker member (9) using holding members (11) which provide two additional points of support for the understructure (2).