A cargo handling system is disclosed. In various embodiments, the cargo handling system includes a first rail defining an upward facing surface and a longitudinal direction and a lateral direction; a platform having a first recessed channel configured to engage an upper portion of the first rail to prevent a movement of the platform in the lateral direction and configured for rolling engagement with the first rail; and a first drive assembly disposed within the platform and configured to propel the platform along the first rail in the longitudinal direction, the first drive assembly having a first drive roller and a first motor.