Abstract: A flexible sheet is erected on four rigid poles to form three rectangular sides thus containing the empty space between intermodal freight containers on consecutive flat-bed rail cars thereby reducing the aerodynamic drag which results from the sizeable gap between containers which is not present between traditional box cars. The apparatus can be raised and lowered by a rope and pulley mechanism, and can be separated into halves to allow detachment of consecutive rail cars.

Abstract: A drag reducer to be mounted on the rear face of a truck or other vehicle. It is comprised of an enclosed bag in the shape of a truncated cone with one or more elastic cord(s) encircling it. Air is introduced into the drag reducer upon forward motion of the vehicle via a tube, the open end of which is facing the direction of motion. As air pressure is increased in the drag reducer with increasing forward velocity the tension in the surface of the bag causes the elastic cord(s) to be extended allowing the drag reducer to reach its fully expanded shape. At slow driving speeds the elastic cord(s) contract and prevent the drag reducer from falling or being blown by cross winds over the rear signal lights or license plate and from touching the road in the case of larger more aerodynamically effective drag reducers.