Abstract: Device and method for the mutual positioning of shell parts. Such shell parts can be used for constructing a large cylinder, for example a silo. The shell parts are provided with end flanges which extend at right angles thereto. Once the shell parts have been brought into the correct position, the end flanges are connected to one another in any suitable way. It is proposed to position the shell parts and/or end flanges with respect to one another in the desired position by arranging supporting rollers on the side where there are no end flanges. On the other side, clamping rollers are used which are at an angle to one another. A combination of in each case a supporting roller and a clamping roller provides both the correct mutual positioning of the shell parts with respect to one another and the pressing against one another of the shell parts.