A storage and retrieval system is provided. The storage and retrieval system having a frame and a shuttle movable within the frame, the shuttle having a carriage extending at least partially between a top and bottom of the frame. At least one tension member extends between a first and second ends of the frame and is coupled to the shuttle. At least one drive member extends between the first and second ends of the frame and is coupled to the shuttle. The at least one drive member and the at least one tension member project from opposite sides of the shuttle towards respective first and second ends of the frame and effect stabilization of the carriage against at least rotation relative to the frame. The at least one tension member crosses the at least one drive member and the at least one drive member effects movement of the shuttle.