A comminuting machine including a frame, an infeed conveyor connected to the frame, a hammer mill connected to the frame, the hammer mill including a hammer mill housing substantially surrounding the hammer mill, a containment system substantially surrounding a comminuting portion of the comminuting machine, the containment system includes at least one cage, the at least one cage including a cage frame extending to substantially block projectile travel paths through openings of the comminuting machine, the cage frame being connected to the frame, and a drive unit movably coupled to the frame for effecting movement of the at least one cage relative to the comminuting portion of the comminuting machine without disconnecting the cage frame from the frame.