Abstract: A power operated industrial door to enclose a doorway in a building. The door comprises a pair of flexible curtains, one vertical side edge of each curtain being secured to the building adjacent the doorway, while the upper horizontal edge of each curtain is attached to a plurality of trolleys that are mounted for movement on tracks disposed above the doorway. One trolley associated with each curtain is secured to an endless drive cable, while the remaining trolleys are freely mounted on the cable so that operation of the cable will move the curtain between open and closed overlapping positions. The upper edge of each curtain is connected to the trolley in a manner such that the curtain will be uniformly folded when moved to the closed position. Weights, in the form of metal shot, can be positioned in elongated pockets along the movable vertical side edge of each curtain, as well as at the bottom of the curtain to aid in resisting wind loads.This is a continuation of application Ser. No.