Method and apparatus for making tanks from plates

A method for the construction of a cylindrical jacket for a vertical tank from plates connected to one another comprising:

• forming a bottom part of said jacket in a portion of a ring of said plates connected to one another;
• building up said bottom ring with an upper helically-shaped edge of said plates connected to one another to thereby provide a top part of the sides of said jacket;
• forming a cover part comprising a cover with a ring of plates attached thereto, said cover being formed with a lower helically shaped edge part, said cover part being placed upon the bottom part such that space for the insertion of additional plates is provided;
• attaching plates to the side plates at the sides of the jacket while providing a stepwise displacement of the cover part relative to the bottom part with said plates attached along the helical line following the edge of the bottom part and attaching the plates until the cover part is finally connected to the jacket, lifting the cover part along the helical line by a linear lifting movement and a simultaneous rolling movement of the cover part which results from the dead weight of the cover part moving along the surface which is inclined upwardly and in the opposite sense to the inclination of the helical edge of the bottom part;
• and
• completing the attachment of the plates about the cover part so displaced and lifted to complete the construction.