Abstract: A transfer trailer defines a container for directly receiving articles from a loading apparatus and is removably attachable to a tractor for transporting the articles. The trailer includes a floor, a top covering spaced from the floor and adapted to substantially cover a top of the container, and at least a pair of walls adapted to substantially cover respective sides of the container and extend substantially between the floor and the top covering. At least one of the pair of walls and the top covering are movable relative to the floor between a closed position and an opened position. When the movable wall and the top covering are in the opened position, the trailer provides an opening into the top and the respective side of the container for directly receiving the articles from the loading apparatus. The trailer includes also a controller for controlling the movement of the movable wall and the top covering between the closed position and the opened position.