The Spiral Method
- an ingenious and safe working method
- The spiral method is used to install tanks without using scaffolding. The procedure involves gradually rotating the tank upwards, which means that the work can be carried out in a small area from one and the same place. This method can also be used when dismantling existing tanks, thus achieving the greatest possible safety.
- With this method, the lower sheet casing is placed at ground level. The height of the sheet metal plates with horizontal bottom side gradually increases, thus forming a spiral sloping upwards by the width of one sheet-metal plate of the assembled sheet casings upper edge.
- Suspended jacks are placed on this upper edge and on these jacks, we place the uppermost sheet casing, whose lower edge forms an equivalent spiral. The roof is built onto the upper edge, which is horizontal. The upper section is the rotated along the helix and a new sheetmetal plate is placed in the opening and welded to the upper section. We rotate once again so that yet another sheet-metal plate can be placed in the same position. When the structure has reached its full height, the jacks are removed and the last sheet-metal plate is welded into position.
- Since all the sheet-metal plates are welded in place from the same position at ground level, only a small work area is required and weather protection can be provided together with and optimum work environment.