Articulated-Tug Barges (ATBSs)
consist of a tank vessel (barge) and a large, powerful tug that is positioned in a notch in the stern of the barge, which enables the tug to propel and maneuver the barge. Unlike an ITB (Integrated Tug/Barge), where the tug and barge are locked together in a rigid connection and become for practical purposes one unit, the ATB has an articulated or "hinged" connection system between the tug and barge. This allows movement in one axis, or plane, in the critical area of fore and aft pitch.
