Abstract: A method for manufacturing large tanks according to the "from the top and down" method, comprising manufacturing the roof of the tank first at ground level and then successively attaching generally cylindrical plates one below the other as the completed part of the tank is raised in stages. The plates each have lifting lugs which alternately cooperate with lifting units for successively raising the partially completed tank and with a guide rail which is used for guiding of a welding machine. The guide rail is preferably adjustably suspended relative to each lug so that the distance from the guide rail to the lower edge of the plate sweep, i.e. where the welding seam is to be made, can be precisely adjusted.