Abstract: An apparatus that raises and lowers a rotatable vestibule of the type used in airports to transfer passengers from a terminal building to a passenger loading bridge. A first plurality of telescoping columns are interconnected to and passively follow a second plurality of telescoping columns disposed interiorly of and in concentric relation with said first plurality of columns when the second columns are activated. J-shaped bushings made of Nylitron facilitate the extension and retraction of the columns and flat sections of that material provide additional bearing surfaces at other locations of the apparatus. The J-shaped bushing also provides stops that limit the extension of the apparatus.