A steerable, retractable power drive unit (SRPDU) is provided for installation into a transport vehicle for moving cargo in mutually perpendicular directions, such as a doorway area where containers need to move both laterally and longitudinally in a cargo vehicle. The SRPDU rotates upon application of an external command, to orient the drive unit in the required direction and to drive the cargo containers. Embodiments include an SRPDU comprising a stationary support for fixedly attaching to a vehicle structure, and a rotating support rotatably mounted to the stationary support. A drive assembly is movably mounted to the rotating support, the drive assembly comprising a roller and a first electronically controlled electric motor for rotating the roller. A lift assembly mounted to the drive assembly has a second electronically controlled electric motor for moving the drive assembly relative to the rotating support from a retracted position substantially within the rotating support to an extended position with the roller in driving abutment against the cargo. A rotation drive assembly has a third electronically controlled electric motor on the rotating support for rotating the rotating support relative to the stationary support. An electronic controller controls the first, second and third motors.