摘要 |
According to the present invention, when a side wall of a cylindrical storage tank is cut away from a bottom plate and the sidewall is cut in spirally from the bottom end toward the top end to remove the cut-away pieces, temporary supporting for gradually lowering the bottom ends of the sidewall at a cut-in portion in accordance with the progress of the work of removal is successively transferred with the progress of the work of removal. According to the present invention, the work can be performed safely, the cost is low, the work can be performed when there is other structure therearound, and moreover, the work can be performed easily without providing a rotatable support member and rotating the top side of the storage tank. <IMAGE> |