The present invention provides a fastening assembly system for applying fasteners along the seams of a cylindrical structure. The fastening apparatus includes a base unit which releasably attaches to a cylindrical structure, and a first fastening device coupled the base unit for applying fasteners along a seam of the cylindrical structure. The base unit may be embodied as either two crescent shaped members in parallel alignment for attaching to the upper half of the cylindrical structure. Alternatively, the base unit may include a base plate that is attachable to the floor beams on the interior of the cylindrical structure. In the preferred embodiment, the first fastening device cooperate with a second fastening device located on the opposite side of the cylindrical structure during the fastening process.